ULTIMATE AND PROXIMATE FACTORS UNDERLYING SEASONALITY ......... 81 NEUROENDOCRINE MECHANISMS UNDERLYING SEASONALITY ................ 83 Activational Mechanisms ........................................................................ 83 Timing Mechanisms .............................................................................. 94 HUMAN SEASONALITY ..............................................

Our goal was to challenge both normal controls and patients with seasonal affective disorders (SAD) to various light histories and then measure their retinal response modulation using the electroretinogram (ERG) in both winter and summer. In winter and summer, 11 normal controls and 12 SAD patients were exposed to three different light conditions for 1 h (10,000, 100 and 5 lux) followed by an E...

The risk of suicide is high amongst individuals with bipolar affective disorder and mixed affective state. Research has shown that the suicide risk increases during both rapid-cycling and mixed affective states in bipolar. This article reviews the recent research of patients with bipolar and mixed affective state and suicide risk and highlights the reasons and potential benefits of factoring th...

Background: Seasonal rhythms in mood and behavior (seasonality) have been reported to occur in the general population. Seasonal affective disorder, a clinically diagnosed syndrome, is believed to represent the morbid extreme of a spectrum of seasonality. Two types of seasonality have been clinically described: one characterized by a winter pattern and a second by a summer pattern of depressive ...

Loss of control eating confers risk for excess weight gain and exacerbated disordered eating. Affect theory proposes that loss of control eating is used to cope with negative mood states. Self-report data suggest that negative affect may contribute to the etiology of loss of control eating, but this theory has not been well-tested using laboratory paradigms. We examined associations between pre...

BACKGROUND Low levels of light exposure at critical times are thought to cause seasonal affective disorder. Investigators, in studies demonstrating the usefulness of bright light therapy, also have implicated light's role in non-seasonal depression. The precise cause of postpartum depression has not been delineated, but it seemed possible that new mothers would spend reduced time in daylight. T...

BACKGROUND Seasonal affective disorder (SAD) is now a well-described form of depressive disorder. However, relatively little research has focused upon psychosocial factors and SAD. AIMS To determine the association between demographic/psychosocial factors and increased reported seasonal patterns of mood disorder (seasonality) and SAD in a community sample in the UK. METHOD A total of 1250 p...

OBJECTIVE To determine if the antidepressant effect of 1 hour of light therapy is predictive of the response after 1 and 2 weeks of treatment in patients with seasonal affective disorder (SAD). PATIENTS Twelve patients with SAD. SETTING National Institutes of Health Clinical Center, Bethesda, Md. INTERVENTIONS Light therapy for 2 weeks. OUTCOME MEASURES Scores on the Seasonal Affective ...

BACKGROUND We investigated a possible mechanism of action for the antidepressant response to light-phase advances of the circadian clock-by measuring the onset of melatonin secretion before and after light treatment in the morning or evening. METHODS Plasma melatonin was sampled in 42 patients with seasonal affective disorder, in the evening or overnight while depressed and after 10 to 14 day...

BACKGROUND Seasonal depression has generated considerable clinical interest in recent years. Despite a common belief that people in higher latitudes are more vulnerable to low mood during the winter, it has never been demonstrated that human's moods are subject to seasonal change on a global scale. The aim of this study was to investigate large-scale seasonal patterns of depression using Intern...