Sleep and depression — results from psychobiological studies: an overview
Section snippets
Sleep disturbances and depression
The relationship between depression and insomniac symptoms is not a one-way street as it was formerly assumed. Recent epidemiological studies strongly suggest that not only is insomnia a typical symptom of depression but, vice versa, insomnia may be an independent risk factor for depression in the long run. The relation between insomnia and depression constitutes a situation with evidence supporting a strong bi-directional linkage.
More than 90% of depressed patients complain about impairments
Polysomnographic studies in depression
Systematic sleep EEG investigations in unmedicated depressed patients using formalized diagnostic criteria were initiated by the group of David Kupfer (Kupfer, 1976, Kupfer and Foster, 1972). Besides sleep continuity disturbances, sleep in depression was characterized by a reduction of slow wave sleep (SWS) and by a shortening of the interval between sleep onset and the occurrence of the first REM period (i.e. REM latency). Further abnormal features included an increased amount of REM sleep, a
Important confounding/intervening influences on sleep parameters
Prior to the discussion of pathophysiological models interrelating sleep abnormalities and depression, several important methodological issues have to be mentioned in order to outline limitations, constraints and problems of polysomnographic research in psychiatry, especially in depression.
How stable are sleep abnormalities in depressed individuals over time?
An important research strategy in psychobiological research is based on the question of whether a given abnormality that is present during the acute disease phase normalizes with remission (‘state’-marker), can still be detected when the disorder is no longer present (‘scar’), or was already present prior to the clinical onset of the disorder and persists throughout the life-span (‘trait’- or ‘vulnerability’-marker). Rush et al. (1986) found a persistence of REM sleep abnormalities in a sample
The impact of antidepressive therapies on sleep in depression
The type of research described under this heading aims at correlating changes of sleep seen during any kind of antidepressive therapy with concurrent or delayed changes of psychopathology. Also relevant is the relationship between pre-therapy sleep abnormality and therapeutic outcome.
Chronobiological models
The most influential model suggested to explain sleep abnormalities in depression based on chronobiological assumptions is the two-process model of Borbély and coworkers (Borbély, 1982, Borbély and Wirz-Justice, 1982). This model attempts to explain the effects of sleep deprivation on depression, REM sleep disinhibition, and reduced SWS. According to this model the so-called process ‘S’ is deficient in depression, which is reflected by a diminution of delta-activity and SWS (see Fig. 2).
Conclusion
After reviewing all theories on the pathophysiology of sleep alterations in depression, one has to conclude that there is still no entirely convincing model capable of explaining all typical changes in the sleep EEG of depressives. The initial hope that the investigation of sleep may be a valuable tool for differential-diagnosis in psychiatry has not been fulfilled. Numerous studies in different psychiatric populations have not conclusively demonstrated specificity in the relationship between
Acknowledgements
We thank Professor Dr Charles Reynolds for his comments and suggestions concerning an earlier version of this manuscript.
References (237)
- et al.
Mono-amine oxidase inhibitors, sleep and mood
Electroencephalog. Clin. Neurophysiol.
(1970) - et al.
The utility of the REM latency test in psychiatric diagnosis: a study of 81 depressed outpatients
Psychiatry Res.
(1982) - et al.
Sleep in fall/winter seasonal affective disorder: effects of light and changing seasons
J. Psychosom. Res.
(1994) - et al.
Depression in adolescents and young adults — polysomnographic and neuroendocrine aspects
J. Affect. Disord.
(1988) - et al.
Comparison of the delta-EEG in the first and second non-REM period in depressed adults and normal controls
Psychiatry Res.
(1992) - et al.
Sex differences in the distribution of EEG frequencies during sleep: unipolar depressed outpatients
J. Affect. Disord.
(1995) - et al.
Sleep loss, a possible factor in augmenting manic episode
Psychiatry Res.
(1996) - et al.
REM latency in neurotic and endogenous depression and the cholinergic REM induction test
Psychiatry Res.
(1983) - et al.
Pilocarpine, an orallly active muscarinic cholinergic agonist, induces REM sleep and reduces SWS in normal volunteers
Psychiatry Res.
(1990) - et al.
Effects of a tryptophan-free amino acid drink challenge on normal human sleep electroencephalogram and mood
Biol. Psychiatry
(1998)
All-night spectral analysis of the sleep EEG in untreated depressives and normal controls
Psychiatry Res.
Sleep disturbance and psychiatric disorders: a longitudinal epidemiology study of young adults
Biol. Psychiatry
Social rhythm stability following late-life spunsal bereavement: associations with depression and sleep impairment
Psychiatry Res.
Sleep electroencephalogram in seasonal affective disorder and in control women: effects of midday light treatment and sleep deprivation
Biol. Psychiatry
Molecular clock genes in man and lower animals: Possible implications for circadian abnormalities in depression
Neuropsychopharmacology
Electroencephalographic sleep studies in depressed outpatients treated with interpersonal psychotherapy. I. Baseline studies in responders and non-responders
Psychiatry Res.
Electroencephalographic sleep studies in depressed outpatients treated with interpersonal psychotherapy. II. Longitudinal studies at baseline and recovery
Psychiatry Res.
Electroencephalaographic sleep correlates of episode and vulnerability to recurrence in depression
Biol. Psychiatry
Sleep onset abnormalities in depressed adolescents
Biol. Psychiatry
Effects of sleep deprivation on the limbic system and the frontal lobes in affective disorders: a study with Tc-99-HMPAO-SPECT
Psychiatric Res. Neuroimaging
Hypthalamic peptide modulation of EEG sleep in depression: a further application of the S-process hypothesis
Biol. Psychiatry
Estimation of the time course of slow wave sleep over the night in depressed patients: Effects of clomipramine and clinical response
Biol. Psychiatry
Inducing lifestyle regularity in recovering bipolar disorder patients: results from the maintenance therapies in bipolar disorder protocol
Biol. Psychiatry
48-hour rapid cycling: results of psychopathometric, polysomnographic, PET imaging and neuroendocrine logitudinal investigations in a single case
J. Affect. Disord.
The influence of carbamazepine on sleep-EEG and the clonidine test in healthy subjects: results of a preliminary study
Biol. Psychiatry
Hypersomnia in major depressive disorders
J. Affect. Disord.
Which endogenous depressive symptoms relate to REM latency reduction?
Biol. Psychiatry
Polysomno-graphic findings and dexamethasone nonsuppression in unipolar depression: a replication and extension
Biol. Psychiatry
REM latency concordance in depressed family members
Biol. Psychiatry
Risk factors in families of unipolar depression. I. Psychiatric illness and reduced REM latency
J. Affect. Disord.
Secular trend in unipolar depression: a hypothesis
J. Affect. Disord.
Sleep abnormalities in depressed children: a hypothesis
Psychiatry Res.
Age related changes in sleep in depressed and normal subjects
Psychiatry Res.
Sleep-onset rapid eye movement after electroconvulsive therapy is more frequent in patients who respond less well to electroconvulsive therapy
Biol. Psychiatry
A cholinergic–adrenergic hypothesis of mania and depression
Lancet
Schlafentzug und anschließende Schlafphasenvorver-lagerung stabilisiert den positiven Schlafentzugseffekt bei depressiven Episoden
Nervenarzt
Concurrent use of REM latency, dexamethasone suppression, clonidine, and apomorphine tests as biological markers of endogenous depression. A pilot study
Psychiatry Res.
Sleep and psychiatric disorders: a meta-analysis
Arch. Gen. Psychiatry
Neuroendocrinological and neurophysiological studies in major depressive disorders: are there biological markers for the endogenous subtype?
Biol. Psychiatry
Sleep-EEG variables as course criteria and predictors of antidepressant therapy with fluvoxamine/oxaprotiline
The cholinergic REM-sleep-induction test with RS 86: State- or traitmarker of depression?
Arch. Gen. Psychiatry
Sleep deprivation combined with consecutive sleep phase advance as a fast-acting therapy in depression: an open pilot trial in medicated and unmedicated patients
Am. J. Psychiatry
Sleep in normal aging and dementia
Sleep
Complex interaction of the sleep–wake cycle and circadian phase modulates mood in healthy subjects
Arch. Gen. Psychiatry
A two process model of sleep regulation
Hum. Neurobiol.
Sleep, sleep deprivation and depression
Hum. Neurobiol.
Insomnia in the elderly: prevalence, gender differences and relationships with morbidity and mortality
Int. J. Geriatric Psychiatry
Sleep parameters in SAD: effects of midday light, season, and sleep deprivation
Sleep Res.
Rapid eye movement sleep characteristics during and after mood disturbing events
Arch. Gen. Psychiatry
Sleep markers for major depressive disorder in adolescent patients
Sleep Res.
Cited by (528)
Closed-loop auditory stimulation of sleep slow oscillations: Basic principles and best practices
2023, Neuroscience and Biobehavioral ReviewsSubjective and objective sleep and circadian parameters as predictors of depression-related outcomes: A machine learning approach in UK Biobank
2023, Journal of Affective DisordersFunctional connectivity between dorsal attention and default mode networks mediates subjective sleep duration and depression in young females
2023, Journal of Affective Disorders