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Discerning depressive symptoms in patients with obstructive sleep apnoea

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The assessment of depression in obstructive sleep apnea (OSA) is confounded by the overlap in symptoms between the disorders. Romola Bucks suggests nonoverlapping depressive symptoms may be useful discriminators of clinical depression amongst patients with untreated, symptomatic OSA.

Image courtesy of interviewee. March 13, 2024

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The transcript discusses obstructive sleep apnea (OSA), a sleep-related breathing disorder characterized by partial or complete blockage of the airway, leading to interrupted breathing during sleep. This video video condition can have negative effects on both physical and mental health, particularly increasing the prevalence of depression among those affected.

The speaker, a psychologist, focuses on the mental health impacts of OSA, especially the relationship between sleep apnea symptoms and the symptoms of depression, leading to questions about whether depression rates in individuals with OSA are overestimated. They note that overlapping symptoms of OSA and depression, such as fatigue and irritability, complicate diagnosis and treatment.

The discussion highlights a study investigating the effects of Continuous Positive Airway Pressure (CPAP) therapy on depression in individuals with OSA. The study tracked participants' depression scores over a 12-week CPAP treatment period. Findings indicated that CPAP treatment generally led to improvements in depression symptoms, particularly in those with overlapping symptoms related to OSA. However, non-overlapping symptoms of depression, which are more characteristic of depression itself (like hopelessness and guilt), showed less improvement.

Key findings included:
1. Both overlapping and non-overlapping depression symptoms improved with CPAP use, but the improvement was greater for overlapping symptoms.
2. The extent of CPAP usage correlated with reductions in depression scores, especially for overlapping symptoms, indicating that adherence to the treatment is essential for improving mental health.

The speaker concluded that CPAP effectively alleviates overlapping symptoms of depression in OSA but may not address the more severe non-overlapping depressive symptoms, suggesting that individuals with significant non-overlapping symptoms may require additional treatments, such as medication or cognitive-behavioral therapy. The speaker proposed the need for an OSA-specific depression scale to better assess and address the mental health needs of patients with sleep apnea.

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Obstructive sleep apnea.

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OSA is a breathing disorder that happens during sleep.

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And what a pa basically happens is that the upper airway

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partially or completely obstruct, so it kind

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of collapses and smushes down.

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Think standing on a, on a hose pipe.

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And as a result, when you are trying to breathe in

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and breathe out in normal respiration, normal breathing,

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the airway is obstructed, partial your holy,

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and you can't get the air in

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and you can't breathe out the carbon dioxide.

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This is spectacularly bad for the body and the brain.

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And usually what happens is the individuals,

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will wake up either wholly

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or partially from deeper stages to lighter stages of sleep,

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or actually wake up completely to restart breathing.

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If you're sleeping in the bed next to someone with OSA,

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you will hear them go like this as they restart breathing,

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and there might be periods of silence or snoring before that

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and it can happen hundreds of times a night.

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And we have a metric of

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how severe your apnea is called the a HI,

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and it basically is the number of times you partially

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or completely obstruct, and that obstructs

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and drop your airflow

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and drops your blood oxygen levels below a acquired level

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for at least 10 seconds at a time.

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And that's the number of times per hour

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of sleep is the a HI.

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And, you know,

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a mild a HI would be about five times, an hour.

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You, you don't breathe properly for 10 or more seconds.

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Moderate might be, 15 times an hour, severe 30

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or more times an hour.

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And there are people who can spend as much as half

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of the night not breathing properly.

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So this is a significant disorder.

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Now, the context of the study is that

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sleep apnea is associated with a whole lot of physical

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and mental health difficulties.

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And I'm a psychologist, so I'm particularly interested in

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the mental consequences of apnea.

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And I'm particularly interested in,

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the effects on mental health, particularly depression,

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because it turns out

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that depression is more common in people

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with sleep apnea than it is in the general public, by,

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by a significant margin.

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And of course that's really critical

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because depression itself is associated with lots

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of negative consequences

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and may interfere with somebody's ability to engage

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with treatment for sleep apnea.

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So there's a vicious cycle.

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Um, but the problem is, is that depression is made up

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of constellation of different kinds of symptoms, some

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of which are also symptoms of sleep apnea in and of itself.

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So there is overlap between the symptoms of depression

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and the symptoms of sleep apnea.

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So one of the critical questions is, is are we

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overestimating the prevalence of depression and sleep apnea?

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And when we treat depression symptoms in sleep apnea,

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are we actually treating the depression

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or are we treating the, the, the symptoms of sleep apnea

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that happen to overlap and look like depression?

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There was very little re at all asking the question of

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of whether,

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there is a difference following sleep,

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AP treatment in depression,

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symptom improvement depending on the type of symptom

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that you've got, whether they're

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overlapping or not overlapping.

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So there's most studies basically ask the question,

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does CPAP treat depression in sleep apnea?

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Now, CPAP, it just in case most people will know,

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but just in case, is a, is a treatment

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where you wear a mask over the nose or mouth

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and it applies, blows.

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There's a machine that blows air,

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through a pipe into the mask, that helps

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to keep the airway open.

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So it helps to keep the, the, the air flowing into,

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into the lungs, which is really important.

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So most studies have just asked,

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does CPA treat depression in the answers?

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Yes, it does, right?

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But we wanted to know, we wanted

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to know a different question to the extent

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that an individual actually uses the therapy

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because not everybody does use it perfectly.

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What is the effect of that therapy on depression symptoms?

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And particularly, is there a different effect

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of CPAP on overlapping and non-overlapping symptoms?

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So let me explain to you what I mean by overlapping

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and non-overlapping, just to be a little bit more concrete.

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The kinds of symptoms that you see in OSA

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that could look like depression

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'cause you also see them in depression,

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are things like the behavioral consequences, like a loss

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of libido, changes in menstrual symptoms, mental

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and physical, slowing, what we call psychomotor retardation.

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Uh, tension and irritability, really common,

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as we all know, when you don't sleep.

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Um, physical anxiety symptoms.

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So kind of trembling in the tummy, heart palpitations,

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that kind of thing, sleep difficulties, which of course,

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you know, you get in both, loss of energy

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and some changes in co in thinking.

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So people feeling they're a bit slower mentally,

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they can't think as clearly,

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they can't problem solve as clearly.

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And you can see why that could be both a symptom

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of depression and a symptom of of sleep apnea.

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If you don't sleep well, if your brain's not getting an hypo

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oxygen, of course you're not gonna think as clearly,

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but it, that's not necessarily the case

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that you're also depressed.

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So those are the overlapping symptoms.

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And the non-overlapping symptoms are things that

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as a psychologist, I think of as kind

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of more cardinal features, the depression like agitation,

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loss of weight and appetite, depressed mood,

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feeling like everything is terrible

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and nothing is can can, can never get better, hopeless,

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helpless, guilt, suicidal thinking,

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changes in insight and awareness

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or the opposite actually a kind of feeling

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of disconnection from your feelings

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that you don't really feel anything is real.

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A sort of derealization

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and hypochondriasis are kind of complaining of lots

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of physical problems when actually is there.

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And they are very different qualitatively to the first set

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that I've just described.

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But they are all symptoms of depression.

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And the problem is, is that in all the previous trials

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that have looked at whether CPAP, treats depression,

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they've used a range of different measures

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with different numbers and different proportions

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of those overlapping and non-overlapping sym

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items or symptoms.

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And actually we, a previous paper we did,

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was a meta-analysis of the prevalence

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of depression in sleep apnea.

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And we found a direct relationship between how many

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symptoms in a scale.

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So the proportion of symptoms in a scale

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that were overlapping a direct relationship between that

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and the prevalence of depression.

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Simply put, if you used a scale with very high numbers

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of overlapping symptoms, you reported a higher prevalence

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of depression in your sample than if you lose to scale

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with lower, numbers

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or proportions of overlapping symptoms.

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So that suggests to me that our understanding of

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what is the true nature

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of depression in sleep apnea is quite muddled.

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It is challenging.

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And we could have a whole existential argument about, well,

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a depression symptom is a

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depression symptom, it's still a bad thing.

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And I would agree, but I do think if we are trying

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to work out, well, who needs more help than OSA

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to treat their depression, we need

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to know the answer to this question.

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So this is a 12 week single arm study.

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So we didn't have a control group

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because we were only interested in individual differences.

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So what happened within the individuals we studied,

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so everybody got CPAP, they had never had CPAP before.

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We had to exclude all the sorts of things

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that might've mi the water like psychosis and insomnia

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and central apnea,

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which is a different kind of sleep disorder.

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Um, people who couldn't speak English well enough

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to follow the questionnaires, that kind of thing.

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Um, and we basically, assessed them at baseline.

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They then went into 12 weeks of CPAP treatment

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and we assessed them at week three, week eight and week 13.

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So after the 12 weeks of CPAP treatment,

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and we used a questionnaire measure called the ham D

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and we used that because it allowed us

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to divide the symptoms into overlapping

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and non overlapping as I've described.

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And because there were different numbers

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of symptoms within the questionnaire

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that fit into those categories, we created two scores,

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but as, as a proportion of the number of items.

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So we produced percentage scores for those.

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We also just calculated the standard total score in raw

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points that you would expect to see.

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And what we wanted to do was to see whether,

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well obviously how depressed were they to begin with,

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and then what was the change in depression score over time

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and was it different between overlapping

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and non-overlapping symptoms?

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So we then did what's called growth curve modeling,

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which allows you to,

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describe the initial starting score at baseline

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and then a slope of change, a change function over time.

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And if I may, I could share a, an image

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with you when we're talking about the results that, that

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I think captures what I'm trying to describe in words.

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The first thing I think I want to say.

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And if you could just mentally combine those two lines

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that I'm showing you together, which are the overlapping

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and non-overlapping symptoms together,

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the first thing I wanted to say is

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everyone's depression improved.

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So on average they started at about 11 points

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and they went down about three, 3.2 points per visit,

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but it wasn't linear.

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So what you can see from those two separate slopes

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and imagine them smushed together, is that there was a,

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a faster change between baseline

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and week three than across the rest of the,

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the 12 weeks of treatment.

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What I think you can also see, I think it's really obvious

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that the solid line here is the overlapping symptoms

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and the dotted line is the non-overlapping symptoms.

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So what you'll see, first of all, is that everyone started

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with higher percentage scores are overlapping symptoms than

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non-overlapping symptoms, which is not surprising given

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that they're overlapping with OSA.

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So you would expect that and that both overlapping

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and non overlapping symptom scores improved over time

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and those changes were significant.

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What you'll also see is that the, the slope

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of change is much steeper,

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even though it still flattens off, it's much steeper overall

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for the overlapping symptoms.

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So they started at about 30%

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and they improved on average about 9% per visit.

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But again, it flattened off, off

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for the non-overlapping symptoms.

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They started at about, what was it,

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12 percentage points

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and went down by about three percentage points per visit.

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Again, flattening off.

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So yes, both kinds of symptoms improved with treatment,

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but overlapping more than non-overlapping, you might say.

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Well, so what, what we wanted to know was,

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is this a function of

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how much people actually engage with their therapy?

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'cause as I said, lots of people start CPAP,

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but don't continue it.

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Lots of people don't use it.

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The required number of hours a night.

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And the rough rule

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of thumb is if you use it fewer than four hours a night,

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you're probably not using it enough.

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I mean, you should really use it the whole night,

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but we kind of roughly say four hours

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or more is kind of better than less.

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So what we did was we looked

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to see whether there was a relationship between,

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how quickly people's depression improved within overlapping

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and non-overlapping symptoms

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and how much they used their CPAP.

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And there was, but only for the overlapping symptoms.

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So those people who use their CPAP device,

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more hours on average across the 12 weeks

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or more percentages of a greater percentage of nights

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for more than four hours, four

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or more hours had a steeper slope of decline.

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So you could imagine that this average is made up

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of a whole load of different trajectories.

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Each person gets their own slope function.

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So someone who uses their CPA more would have a steeper

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slope than someone who uses their C who use their CPAP less.

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And that association was significant.

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And that is, I think, a very interesting finding,

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particularly as it contrasts with the fact

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that there was no relationship between

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how much people use their CPA treatment

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and the change, the rate

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of change in non-overlapping depression symptoms.

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The first conclusion, I guess I want to draw is,

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is the good news story is this confirms

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that CPAP improves depression for everyone.

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And I think we don't wanna lose sight of

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that in the excitement about the differences.

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So the proportion who started out depressed,

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in a sense of they met criteria for mild

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or more severe depression was 63% and that went down to 24%.

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So that's a, that's a big change.

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Now you might say, well, that's just a placebo effect.

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There's no control group in this study

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because we weren't doing a randomized controlled trial.

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But placebo effects wouldn't explain the differences

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between non-overlapping and overlapping symptoms.

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They just wouldn't. So the second thing is to, you know,

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we conclude is that CPAP use does appear

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to improve overlapping symptoms more than non-overlapping,

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and in a way that is related to how much

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of the treatment people were using.

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So, good news story, if you're trying to say

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to your patient, you really need to use CPAP

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'cause it's gonna help your depression, and the more you use

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it, the more it will help your depression, right?

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Regardless of the type of depression symptom.

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But the relationship between CPAP use

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and depression was really only significant

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for overlapping symptoms.

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So if you were being really radical, you could conclude

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that CPAP doesn't treat depression, it only treats OSA

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I'm being provocative here for

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that is a conclusion you could draw, right?

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Um, because the symptoms that seem to be more persistent

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after CPAP treatment were the non-overlapping ones, the ones

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that as a psychologist I see as cardinal features

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of depression, the hopelessness, the helplessness,

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the guilt, the, the, you know, the negativity,

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the depressive mood, the kind of,

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it's all hopeless, helpless, worthless.

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I am a useless individual. Really, really strong symptoms.

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So it, if it could mean that CPAP doesn't treat

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depression in OSA, maybe what it means is, is

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that those people who have a lot

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of those non-overlapping symptoms need something else apart

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from CPAP to treat their depression.

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There's no doubt they need the CPA, right?

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For other reasons that I'm interested in,

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which is cognition thinking and memory skills.

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We know that you is terrible for thinking and memory skills.

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We know it's terrible for hypertension.

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It's a risk factor for diabetes.

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So you've got to have the CPAP,

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but if you are someone who is depressed and

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That depression has a lot

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of those non-overlapping features, then I think it means

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that you need something else, perhaps, medication,

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perhaps something like a cognitive behavioral

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therapy or CBT.

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The other thing that I think is a potential, kind

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of next step from this would be, well,

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maybe we should be designing an OAA

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specific depression scale.

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Because that way we might be able to actually talk about

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what is the true prevalence

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of depression in obstructive sleep apnea

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and how best to treat depression in sleep apnea.

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That isn't of the overlapping kind.

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And I haven't seen anyone yet take up the,

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the challenge of that

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because some people would say,

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well it doesn't matter if you're treating depression

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symptoms, you're treating depression, who cares?

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And others like me kind of go, but maybe it does.

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And I actually dunno the answer.

00:00 - Obstructive sleep apnea. OSA is a breathing disorder that happens during sleep. And what a pa basically happens is that the upper airway partially or completely obstruct, so it kind of collapses and smushes down. Think standing on a, on a hose pipe.

00:16 - And as a result, when you are trying to breathe in and breathe out in normal respiration, normal breathing, the airway is obstructed, partial your holy, and you can't get the air in and you can't breathe out the carbon dioxide. This is spectacularly bad for the body and the brain. And usually what happens is the individuals, will wake up either wholly or partially from deeper stages to lighter stages of sleep, or actually wake up completely to restart breathing.

00:45 - If you're sleeping in the bed next to someone with OSA, you will hear them go like this as they restart breathing, and there might be periods of silence or snoring before that and it can happen hundreds of times a night. And we have a metric of how severe your apnea is called the a HI, and it basically is the number of times you partially or completely obstruct, and that obstructs and drop your airflow and drops your blood oxygen levels below a acquired level

01:13 - for at least 10 seconds at a time. And that's the number of times per hour of sleep is the a HI. And, you know, a mild a HI would be about five times, an hour. You, you don't breathe properly for 10 or more seconds. Moderate might be, 15 times an hour, severe 30 or more times an hour. And there are people who can spend as much as half of the night not breathing properly.

01:37 - So this is a significant disorder. Now, the context of the study is that sleep apnea is associated with a whole lot of physical and mental health difficulties. And I'm a psychologist, so I'm particularly interested in the mental consequences of apnea. And I'm particularly interested in, the effects on mental health, particularly depression, because it turns out that depression is more common in people

02:05 - with sleep apnea than it is in the general public, by, by a significant margin. And of course that's really critical because depression itself is associated with lots of negative consequences and may interfere with somebody's ability to engage with treatment for sleep apnea. So there's a vicious cycle. but the problem is, is that depression is made up of constellation of different kinds of symptoms, some

02:33 - of which are also symptoms of sleep apnea in and of itself. So there is overlap between the symptoms of depression and the symptoms of sleep apnea. So one of the critical questions is, is are we overestimating the prevalence of depression and sleep apnea? And when we treat depression symptoms in sleep apnea, are we actually treating the depression or are we treating the, the, the symptoms of sleep apnea that happen to overlap and look like depression? There was very little re at all asking the question of

03:06 - of whether, there is a difference following sleep, AP treatment in depression, symptom improvement depending on the type of symptom that you've got, whether they're overlapping or not overlapping. So there's most studies basically ask the question, does CPAP treat depression in sleep apnea? Now, CPAP, it just in case most people will know, but just in case, is a, is a treatment

03:30 - where you wear a mask over the nose or mouth and it applies, blows. There's a machine that blows air, through a pipe into the mask, that helps to keep the airway open. So it helps to keep the, the, the air flowing into, into the lungs, which is really important. So most studies have just asked, does CPA treat depression in the answers? Yes, it does, right?

03:54 - But we wanted to know, we wanted to know a different question to the extent that an individual actually uses the therapy because not everybody does use it perfectly. What is the effect of that therapy on depression symptoms? And particularly, is there a different effect of CPAP on overlapping and non-overlapping symptoms? So let me explain to you what I mean by overlapping and non-overlapping, just to be a little bit more concrete. The kinds of symptoms that you see in OSA

04:22 - that could look like depression 'cause you also see them in depression, are things like the behavioral consequences, like a loss of libido, changes in menstrual symptoms, mental and physical, slowing, what we call psychomotor retardation. tension and irritability, really common, as we all know, when you don't sleep. physical anxiety symptoms. So kind of trembling in the tummy, heart palpitations, that kind of thing, sleep difficulties, which of course,

04:52 - you know, you get in both, loss of energy and some changes in co in thinking. So people feeling they're a bit slower mentally, they can't think as clearly, they can't problem solve as clearly. And you can see why that could be both a symptom of depression and a symptom of of sleep apnea. If you don't sleep well, if your brain's not getting an hypo oxygen, of course you're not gonna think as clearly, but it, that's not necessarily the case

05:15 - that you're also depressed. So those are the overlapping symptoms. And the non-overlapping symptoms are things that as a psychologist, I think of as kind of more cardinal features, the depression like agitation, loss of weight and appetite, depressed mood, feeling like everything is terrible and nothing is can can, can never get better, hopeless, helpless, guilt, suicidal thinking, changes in insight and awareness

05:44 - or the opposite actually a kind of feeling of disconnection from your feelings that you don't really feel anything is real. A sort of derealization and hypochondriasis are kind of complaining of lots of physical problems when actually is there. And they are very different qualitatively to the first set that I've just described. But they are all symptoms of depression. And the problem is, is that in all the previous trials

06:08 - that have looked at whether CPAP, treats depression, they've used a range of different measures with different numbers and different proportions of those overlapping and non-overlapping sym items or symptoms. And actually we, a previous paper we did, was a meta-analysis of the prevalence of depression in sleep apnea. And we found a direct relationship between how many symptoms in a scale.

06:35 - So the proportion of symptoms in a scale that were overlapping a direct relationship between that and the prevalence of depression. Simply put, if you used a scale with very high numbers of overlapping symptoms, you reported a higher prevalence of depression in your sample than if you lose to scale with lower, numbers or proportions of overlapping symptoms. So that suggests to me that our understanding of what is the true nature

07:00 - of depression in sleep apnea is quite muddled. It is challenging. And we could have a whole existential argument about, well, a depression symptom is a depression symptom, it's still a bad thing. And I would agree, but I do think if we are trying to work out, well, who needs more help than OSA to treat their depression, we need to know the answer to this question. So this is a 12 week single arm study.

07:22 - So we didn't have a control group because we were only interested in individual differences. So what happened within the individuals we studied, so everybody got CPAP, they had never had CPAP before. We had to exclude all the sorts of things that might've mi the water like psychosis and insomnia and central apnea, which is a different kind of sleep disorder. people who couldn't speak English well enough to follow the questionnaires, that kind of thing.

07:48 - and we basically, assessed them at baseline. They then went into 12 weeks of CPAP treatment and we assessed them at week three, week eight and week 13. So after the 12 weeks of CPAP treatment, and we used a questionnaire measure called the ham D and we used that because it allowed us to divide the symptoms into overlapping and non overlapping as I've described. And because there were different numbers of symptoms within the questionnaire

08:18 - that fit into those categories, we created two scores, but as, as a proportion of the number of items. So we produced percentage scores for those. We also just calculated the standard total score in raw points that you would expect to see. And what we wanted to do was to see whether, well obviously how depressed were they to begin with, and then what was the change in depression score over time and was it different between overlapping and non-overlapping symptoms?

08:46 - So we then did what's called growth curve modeling, which allows you to, describe the initial starting score at baseline and then a slope of change, a change function over time. And if I may, I could share a, an image with you when we're talking about the results that, that I think captures what I'm trying to describe in words. The first thing I think I want to say. And if you could just mentally combine those two lines that I'm showing you together, which are the overlapping

09:13 - and non-overlapping symptoms together, the first thing I wanted to say is everyone's depression improved. So on average they started at about 11 points and they went down about three, 3.2 points per visit, but it wasn't linear. So what you can see from those two separate slopes and imagine them smushed together, is that there was a, a faster change between baseline and week three than across the rest of the,

09:36 - the 12 weeks of treatment. What I think you can also see, I think it's really obvious that the solid line here is the overlapping symptoms and the dotted line is the non-overlapping symptoms. So what you'll see, first of all, is that everyone started with higher percentage scores are overlapping symptoms than non-overlapping symptoms, which is not surprising given that they're overlapping with OSA. So you would expect that and that both overlapping and non overlapping symptom scores improved over time

10:09 - and those changes were significant. What you'll also see is that the, the slope of change is much steeper, even though it still flattens off, it's much steeper overall for the overlapping symptoms. So they started at about 30% and they improved on average about 9% per visit. But again, it flattened off, off for the non-overlapping symptoms. They started at about, what was it,

10:34 - 12 percentage points and went down by about three percentage points per visit. Again, flattening off. So yes, both kinds of symptoms improved with treatment, but overlapping more than non-overlapping, you might say. Well, so what, what we wanted to know was, is this a function of how much people actually engage with their therapy? 'cause as I said, lots of people start CPAP, but don't continue it.

11:00 - Lots of people don't use it. The required number of hours a night. And the rough rule of thumb is if you use it fewer than four hours a night, you're probably not using it enough. I mean, you should really use it the whole night, but we kind of roughly say four hours or more is kind of better than less. So what we did was we looked to see whether there was a relationship between,

11:21 - how quickly people's depression improved within overlapping and non-overlapping symptoms and how much they used their CPAP. And there was, but only for the overlapping symptoms. So those people who use their CPAP device, more hours on average across the 12 weeks or more percentages of a greater percentage of nights for more than four hours, four or more hours had a steeper slope of decline. So you could imagine that this average is made up

11:51 - of a whole load of different trajectories. Each person gets their own slope function. So someone who uses their CPA more would have a steeper slope than someone who uses their C who use their CPAP less. And that association was significant. And that is, I think, a very interesting finding, particularly as it contrasts with the fact that there was no relationship between how much people use their CPA treatment and the change, the rate

12:18 - of change in non-overlapping depression symptoms. The first conclusion, I guess I want to draw is, is the good news story is this confirms that CPAP improves depression for everyone. And I think we don't wanna lose sight of that in the excitement about the differences. So the proportion who started out depressed, in a sense of they met criteria for mild or more severe depression was 63% and that went down to 24%. So that's a, that's a big change.

12:47 - Now you might say, well, that's just a placebo effect. There's no control group in this study because we weren't doing a randomized controlled trial. But placebo effects wouldn't explain the differences between non-overlapping and overlapping symptoms. They just wouldn't. So the second thing is to, you know, we conclude is that CPAP use does appear to improve overlapping symptoms more than non-overlapping, and in a way that is related to how much of the treatment people were using.

13:15 - So, good news story, if you're trying to say to your patient, you really need to use CPAP 'cause it's gonna help your depression, and the more you use it, the more it will help your depression, right? Regardless of the type of depression symptom. But the relationship between CPAP use and depression was really only significant for overlapping symptoms. So if you were being really radical, you could conclude that CPAP doesn't treat depression, it only treats OSA

13:44 - I'm being provocative here for that is a conclusion you could draw, right? because the symptoms that seem to be more persistent after CPAP treatment were the non-overlapping ones, the ones that as a psychologist I see as cardinal features of depression, the hopelessness, the helplessness, the guilt, the, the, you know, the negativity, the depressive mood, the kind of, it's all hopeless, helpless, worthless. I am a useless individual. Really, really strong symptoms.

14:14 - So it, if it could mean that CPAP doesn't treat depression in OSA, maybe what it means is, is that those people who have a lot of those non-overlapping symptoms need something else apart from CPAP to treat their depression. There's no doubt they need the CPA, right? For other reasons that I'm interested in, which is cognition thinking and memory skills. We know that you is terrible for thinking and memory skills. We know it's terrible for hypertension.

14:42 - It's a risk factor for diabetes. So you've got to have the CPAP, but if you are someone who is depressed and That depression has a lot of those non-overlapping features, then I think it means that you need something else, perhaps, medication, perhaps something like a cognitive behavioral therapy or CBT. The other thing that I think is a potential, kind of next step from this would be, well,

15:10 - maybe we should be designing an OAA specific depression scale. Because that way we might be able to actually talk about what is the true prevalence of depression in obstructive sleep apnea and how best to treat depression in sleep apnea. That isn't of the overlapping kind. And I haven't seen anyone yet take up the, the challenge of that because some people would say,

15:40 - well it doesn't matter if you're treating depression symptoms, you're treating depression, who cares? And others like me kind of go, but maybe it does. And I actually dunno the answer.

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