Subjective sleep, depression and anxiety: inter-relationships in a non-clinical sample.

OBJECTIVES: Previous research confirms the interdependent relationship between poor sleep and depression, but has often focused on objective measures of sleep and overlooked the importance of subjective factors. Insomnia may be maintained by anxiety and perceptions of poor sleep timing, and depression is associated with poor sleep satisfaction, regardless of perceived sleep timing. METHODS: This study explored the contribution of current depression and anxiety to sleep perceptions. Participants (n = 98) completed the Hospital Anxiety and Depression scale, and questionnaires were used to evaluate current and previous psychiatric illness, sleep disorders and prescribed psychotropic medication. RESULTS: A series of ANOVAs and regression analyses indicated that variance in sleep timing perceptions was more likely to be explained by symptoms of anxiety than depression; explained variance (adj. R(2)) 25%, t = 2.361; p = 0.023. The analyses also showed that sleep satisfaction perceptions (adj. R(2) = 20%, t = 3.085; p = 0.004), and those relating to overall quality of life (adj. R(2) = 37%, t = -2.763; p = 0.013), were more likely to be explained by symptoms of depression. CONCLUSIONS: These findings support the observation that anxiety appears related to poorer sleep timing perceptions, while depression appears associated with poor sleep satisfaction. Further research is needed to explore the factors that might maintain poor sleep satisfaction in depression.

The relationship between sleep disturbance and depression.

This paper focuses on several aspects of the relationship between sleep and depression, with particular attention to objective factors and subjective perceptions. It does not address the effect that antidepressants have on sleep, nor does it explore the wider implications of the types and course of depression, age, or other psychiatric conditions. "Normal sleep" is explored, examining typical sleep architecture in individuals without sleep disorders, psychiatric conditions or physical illness. Sleep disorders are reviewed and examined to present the nature of the disturbance and the role that they may play in depression, with particular attention paid to insomnia. Studies have identified a sub-group of insomnia patients (highly distressed poor sleepers), who appear to be less satisfied with their sleep quality than "low distressed poor sleepers", even though they did not differ on sleep timing perceptions. Recent work has shown that depressed individuals to be less satisfied with sleep quality than healthy controls, even though they did not differ on sleep timing perceptions. The evidence presented here supports the view that subjective sleep perceptions play an important role in depression. Poor subjective perceptions of sleep in depression may be associated with faulty cognitions. This has been found extensively in insomnia, but is under-researched in depression.

Antidepressants and their effect on sleep.

Given the relationship between sleep and depression, there is inevitably going to be an effect of antidepressants on sleep. Current evidence suggests that this effect depends on the class of antidepressant used and the dosage. The extent of variation between the effects of antidepressants and sleep may relate to their mechanism of action. This systematic review examines randomised-controlled trials (RCTs) that have reported the effect that antidepressants appear to have on sleep. RCTs are not restricted to depressed populations, since several studies provide useful information about the effects on sleep in other groups. Nevertheless, the distinction is made between those studies because the participant's health may influence the baseline sleep profiles and the effect of the antidepressant. Insomnia is often seen with monoamine oxidase inhibitors (MAOIs), with all tricyclic antidepressants (TCAs) except amitriptyline, and all selective serotonin reuptake inhibitors (SSRIs) with venlafaxine and moclobemide as well. Sedation has been reported with all TCAs except desipramine, with mirtazapine and nefazodone, the TCA-related maprotiline, trazodone and mianserin, and with all MAOIs. REM sleep suppression has been observed with all TCAs except trimipramine, but especially clomipramine, with all MAOIs and SSRIs and with venlafaxine, trazodone and bupropion. However, the effect on sleep varies between compounds within antidepressant classes, differences relating to the amount of sedative or alerting (insomnia) effects, changes to baseline sleep parameters, differences relating to REM sleep, and the degree of sleep-related side effects.

Quantifying subjective assessment of sleep and life-quality in antidepressant-treated depressed patients.

This study sought to establish a method of quantifying subjective perceptions of sleep against perceptions of life-quality and mood, using amended versions of the Pittsburgh sleep diary (PghSD) and quality of life of insomniacs (QOLI) questionnaire. Diaries and questionnaires were self-completed in participants' homes. Outpatients with a DSM-IV diagnosis of major depressive disorder were compared with a healthy control group (with no history, or family history, of depression). Poorer sleepers, as determined by the sleep diary, were significantly more likely to report poorer life-quality and mood perceptions on the subsequent questionnaire. Furthermore, the depressed group reported significantly poorer perceptions of sleep quality and poorer perceptions of life-quality and mood than the control group, even though estimates of sleep disturbance were similar. This may indicate that depressed individuals experience more 'sleep distress' than healthy individuals. These results confirm the extent of subjectively reported sleep disruption in depression and demonstrate the merit of combining the amended PghSD and QOLI to quantify sleep perceptions.

Assessing subjective sleep reports in the first-degree relatives of antidepressant-treated depressed outpatients.

This study sought to investigate whether first-degree relatives of depressed patients report, and react to, sleep perceptions in the same way as the depressed group. Our previous research suggested that depressed individuals may experience greater sleep 'distress' than healthy individuals; we wished to explore whether this was also apparent in their nearest relatives. A sample was recruited of 18 antidepressant-treated patients with a current DSM-IV diagnosis of major depressive disorder, 18 healthy controls, and a group of 10 first-degree relatives for each study group. In accordance with previous findings, poorer sleep perceptions corresponded with poorer life-quality and mood perceptions, and depressed individuals reported poorer sleep perceptions and poorer life-quality/mood perceptions than controls. Additionally, there was evidence of similar sleep reporting between depressed patients and their relatives, and for a difference between these relatives and other non-depressed groups. There was a non-significant trend for depressed patients, and their relatives, to report total sleep time in the same manner as each other, and differently to other non-depressed groups. Reports of poor sleep may be associated with reports of poor mood in depression, but in non-depressed individuals the association may be with a feeling of weariness.