Reversed diurnal variation in depression: associations with a differential antidepressant response, tryptophan:large neutral amino acid ratio and serotonin transporter polymorphisms

Background. Although diurnal variation of mood is a widely recognized symptom of depression, the clinical, neurobiological and psychopharmacological significance of this symptom has not previously been reported.Method. A total of 195 depressed out-patients underwent a detailed clinical and neurobiological assessment, and were then randomized to treatment with either fluoxetine or nortriptyline.Results. Of the 195 depressed patients, 62 had a pattern of reversed diurnal variation (i.e. worse in the evening). Those with reversed diurnal variation had a poorer response to a serotonergic antidepressant, were less likely to have bipolar II disorder, had a higher tryptophan:large neutral amino acid ratio and had different allele frequencies of the polymorphisms in the promoter region of the serotonin transporter.Conclusions. These findings raise the possibility of serotonergic influence on diurnal variation, and that the symptom of reversed diurnal variation is of relevance to antidepressant prescribing.

The 24-Hour Variation of Mood Differs between Morning- and Evening-Type Individuals

This study investigated a 24-hour variation of subjective mood in 16 healthy Morning-type and 13 Evening-type subjects as defined by the time of day at which their oral temperature curve reached its maximum. The subjects were instructed to use a sleep-wake logbook, in which they kept daily records of the ratings of their mood and alertness for a period of two consecutive weeks. For mood as well as for alertness analysis of variance indicated significant interactions between Morning-and Evening-types and time of day. It is concluded that a pronounced diurnal variation of mood can be observed in healthy individuals, which differs between Morning-type and Evening-type subjects.

Cerebral perfusion correlates of depressed mood

BackgroundThe spontaneous diurnal variation of mood and other symptoms provides a substrate for the examination of the relationship between symptoms and regional brain activation in depression.MethodTwenty unipolar depressed patients with diurnal variation of mood were examined at 8 a.m. and 8 p.m. with neuropsychological measures, clinical ratings and single photon emission tomography (SPET). Brain perfusion maps were spatially transformed into standard stereotactic space and compared pixel-by-pixel. A parametric (correlational) analysis was used to examine the relationship between symptom severity and brain perfusion, both between and within subjects.ResultsGlobal depression severity and an independent ‘vital’ depression factor were associated in subjects with increased perfusion in cingulate and other paralimbic areas. In addition there was a probable association between an increase in an anxious-depression factor and reduced frontal neocortical perfusion.ConclusionsDepressive symptom changes are associated with metabolic changes in the cingulate gyrus and associated paralimbic structures.

A longitudinal study of sleep deprivation responses in depression; The variability is highly related to diurnal mood variability

Unequivocal results demonstrating a causal relationship between a disturbance in circadian rhythms and depression have not yet been reported (reviews). However, acute mood changes, such as the antidepressive effect of sleep deprivation, diurnal variations of mood and their interrelationship, are commonly put forward as evidence of the importance of circadian dysregulations in affective disorders. The purpose of the present study is to obtain more insight in the mechanisms underlying these mood changes. The results will be discussed in the context of a recently postulated non-chronobiological explanation.Earlier studies have suggested that the relationship between diurnal variation of mood and the response to total sleep deprivation (TSD) is clear and unambiguous: improvement of mood during the day prior to TSD (a positive diurnal variation) is followed by a positive response (mood improvement) to TSD, while no improvement or deterioration of mood during the day prior to TSD (a negative diurnal variation) may result in no, or even a negative, TSD response (for references see Van den Hoofdakker). However, these conclusions were based on the results from cross-sectional studies, comparing single TSD effects across individuals. Comparison of sleep deprivation effects within individuals, however, revealed that the course of mood during the day prior to TSD is irrelevant for the TSD response. Accordingly, a favourable response to TSD appeared to be related to the patient's propensity to show diurnal mood variations per se, irrespective of their direction.