Depression and Breathing Disorders

First created | 10/10/2003

Last edited   | 05/11/2012

Summary by Maurice M. Ohayon, MD, DSc, PhD

Reference to cite: Ohayon MM, The effects of breathing-related sleep disorders on mood disturbances in the general population. J Clin Psychiatry. 2003 Oct;64(10):1195-200; quiz, 1274-6

 

The results of clinical studies have been mixed:

• Some were showing that obstructive sleep apnea syndrome is associated with higher rates of clinical depression (2, 3, 4) or higher rates of depressive symptomatology (5, 6).

• Other clinical studies have found that obstructive sleep apnea patients do not have higher rates of depression than do individuals with other chronic diseases (7) or control subjects (8, 9).

• Some studies have also measured whether depressive symptomatology is lessened when a breathing-related sleep disorder is treated with continuous positive airway pressure (CPAP) (6, 10). However, the amelioration in the depressive mood could be due to a placebo effect of the CPAP (10).

• One study that examined the sleep architecture of depressive patients with obstructive sleep apnea syndrome found that sleep latency was longer and the percentage of REM shorter in depressed patients without obstructive sleep apnea compared to depressed patients with obstructive sleep apnea (11).

 

 

Research

 

Data about breathing-related sleep disorders and depressive illness were documented only to a clinical level.

The importance of this association in the general population remained undocumented until the realization of this study.

 

 

Method

 

The studied countries were:

   ● The United Kingdom,

   ● Germany,

   ● Italy,

   ● Portugal

   ● and Spain.

 

The target population was all non-institutionalized residents aged 15 years or over with the exception of Portugal, where the minimum age was set at 18 years.

This represented about 206 million Europeans.

 

A two-stage design was used for all countries.

The population of each country was:

• First divided according to its geographical distribution as per the official census data, then telephone numbers were randomly drawn in each geographical area.

• Second, within each household, a member was selected by age and gender using the Kish method (16) in order to maintain the representation of the sample and to avoid bias related to non-coverage error.

 

Participants had to first grant their verbal consent prior to proceeding with the interview.

For subjects younger than 18 years of age, the verbal consent of the parent(s) was also requested.

 

We excluded potential participants who had insufficient fluency in the national language, who had a hearing or speech impairment or with an illness that precluded the feasibility of an interview.

 

The participation rate was:

• 79.6% (4,972 of 6,249 eligible individuals) in the UK;

• 68.1% (4,115 of 6,047 eligible individuals) in Germany;

• 89.4% (3,970 of 4,442 eligible individuals) in Italy;

• 83% (1,858 of 2,234 eligible subjects) in Portugal;

• and 87.5% (4,065 of 4,648 eligible individuals) in Spain.

 

A total of 18,980 subjects participated in the study.

The overall participation rate was 80.4%.

 

 

Results

 

This is the first time that an epidemiological study has attempted to estimate the association between breathing-related sleep disorders and major depressive disorders.

 

Our results show that 0.8% of the general population have both disorders; this represents about 800 individuals out of 100,000.

 

Comparison with other community-based studies

 

• Obstructive sleep apnea syndrome (OSAS)
  Existing prevalence rates for OSAS have been mainly derived from studies on cohorts or from selected samples (13, 28, 29) rather than from representative samples of the general population.
  The prevalence of OSAS observed in this sample is similar to the rate reported by Young et al. (13) in the Wisconsin cohort when comparing the same age range.

• Major depressive disorders
  In this study, the point prevalence of a DSM-IV major depressive episode (4.3%) is comparable to the one-month prevalence reported in the National Comorbidity Survey (NCS) (4.9%) (15).
  However, this is higher than the prevalence obtained in the Epidemiological Catchment Area (ECA) survey (2.2%) (14).
  The main difference is in the definition of major depressive episode.
  In this study, to include as much individuals with a major depressive episode, we did not exclude individuals who also fulfilled the criteria for a manic episode (like the NCS study did).
  When we excluded the individuals with substance abuse or dependence, bipolar disorders or non-affective psychosis, the prevalence of a major depressive episode dropped to 2.4%, which is close to the ECA rate and close also to the 2.1% rate of “pure episode” of major depression reported in the NCS study.

 

Association between breathing-related sleep disorders and major depressive disorders

 

We found a high positive association between major depressive disorder and breathing-related sleep disorders: depressive subjects being five times more likely to have breathing-related sleep disorders than non-depressed subjects.

 

This association remains strong and positive even when controlling for other important factors such as obesity and hypertension.

This result is different from a clinical study that found the association between a breathing-related sleep disorder and depressive symptoms disappeared when controlling for BMI and hypertension (30).

This can be due to the fact that these authors measured only sleep apnea (respiratory disturbance index >=15 events per hours) and based the presence of depression on the CES-D scale.

 

The contradiction found in the literature about the association between breathing-related sleep disorders and depression can be related to the definition used:

• Some studies used only the respiratory disturbance index as a measure of the presence of a breathing-related sleep disorder.
  However, obstructive sleep apnea syndrome and breathing-related sleep disorders diagnosis are more complex clinical entities that require the presence of other clinical symptoms such as excessive daytime sleepiness or non-restorative sleep, two symptoms that are often observed in depressed patients.

• Other studies have attempted to relate the severity of the breathing-related sleep disorder using the RDI to the presence of depression (31).
  The severity of the RDI did not appear related to the presence of depression.
  However, the severity of clinical symptoms of breathing-related sleep disorders was not assessed.
  The severity of fatigue or daytime sleepiness associated with the breathing-related sleep disorder may have influenced the presence of a depressive disorder.

 

psychotic features

 

We also found that psychotic features were positively associated with breathing-related sleep disorders but not as strongly as major depressive episodes.
The association remained even when controlling for the presence of major depressive episodes.
These associations have been seldom investigated although some cases have been reported (32,33).

 

In conclusion, nearly one fifth of subjects with a breathing-related sleep disorder also have a major depressive disorder and a similar proportion of individuals with depressive disorder have a breathing-related sleep disorder.

 

The identification of one of these disorders should prompt physicians to investigate for the presence of the other disorder.

 

More Information

Medical & Psychiatric Correlates
Smoking is positively related to difficulties in initiating sleep and estimated sleep latency.

Although often reported in clinical studies, the association between the use of antihypertensive drugs and insomnia was seldom reported in epidemiological studies.
On sleep patterns, alcohol at bedtime accelerates the sleep onset, increases the amount of slow-wave sleep, decreases the amount of REM sleep and causes sleep disruption in the second half of the sleep period.
About four out of 10 insomnia subjects medicate themselves with over-the-counter medications or alcohol.
Other medications, such as serotonergic reuptake inhibitors (SSRIs), some neuroleptics, some antiparkinsonians and amphetamines may all provoke insomnia among patients using these kinds of medications. Hypnotics and anxiolytics may cause insomnia

 

Morning Headaches

Waking up with a headache is traditionally associated with sleep disorders

 

Hypertension

Obstructive Sleep Apnea Syndrome is an independent risk factor (odds ratio: 9.7) for hypertension. Snoring and breathing pauses during sleep appeared to be non-significant predictive factors.

 

Chronic Pain

 

Depression, Pain and Sleep
Surprisingly, few studies have attempted to determine if a comorbid medical condition in individuals with chronic painful physical disease increased the likelihood of having a major depressive disorder

 

Depression with Psychotic Features

There are little data regarding the prevalence of associated psychotic features in subjects with major depressive disorders in the general population

Sleep Apnea and Depression
Some clinical studies have attempted to determine whether depression limits the recognition and treatment of breathing-related sleep disorders, or if breathing-related sleep disorders play a role in the etiology or course of depressive disorder