[Atypical depression in Japan--39 case series].

UNLABELLED: In Japan, relatively little attention has been paid to atypical depression, which is defined as the presence of mood reactivity and two of four associated features: hyperphagia, hypersomnia, leaden paralysis, rejection sensitivity. The present study was undertaken to obtain detailed clinical information from patients with a diagnosis of atypical depression. We assessed clinical characteristics of each atypical feature, comorbidity of other psychiatric disorders, presence of a stressful life event, and underlying psychological stress in 39 psychiatric outpatients. We also examined the relationship of interpersonal sensitivity to each atypical feature. RESULTS AND DISCUSSION: Mean age of onset was 22 +/- 6, 74% were female, 20 patients (51%) had comorbid social phobia. Thirty (77%) had hyperphagia and 25 of these were women. Twenty (74%) had hypersomnia. Only seven patients reported daytime sleepiness and others (13) reported difficulty in staying awake due to lack of energy. Nineteen (49%) had leaden paralysis. Thirty-two patients (82%) had rejection sensitivity and this symptom correlated with scores of FNE (fears of negative evaluation), LSAS (Liebowits social anxiety scale) and Brief social phobia scale (BSPA). Seven patients reported disappointment in love as a stressful life event preceding the depressive episode. In patients with comorbid social phobia, loss of confidence due to hypersensitivity to rejection or criticism seemed to be the most important factor as a chronic psychologica stress. Seven patients met criteria for bipolar disorder and five out of seven had comorbid generalized social phobia. The clinical and theoretical implications of these findings were discussed.

Endogenous 5-HT inhibits firing activity of hippocampal CA1 pyramidal neurons during conditioned fear stress-induced freezing behavior through stimulating 5-HT1A receptors.

This study examines the activity of hippocampal CA, pyramidal neurons during conditioned fear stress (CFS)-induced freezing behavior in unanesthetized, unrestrained rats. The firing frequency of hippocampal CA1 pyramidal neurons was significantly decreased when conditioned rats exhibited freezing behavior. Firing frequency returned to the baseline after freezing behavior disappeared. The selective 5-hydroxytryptamine (5-HT)1A antagonists, N-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-N-(2-pyridinyl)cyclohexanecarboxamide (WAY-100635), and N-tert-butyl-3-[4-(2-methoxyphenyl)piperazine-1-yl]-2-phenylpropamide (WAY-100135) and 5-HT depletion with parachlorophenylalanine (PCPA) completely abolished the decrease in firing frequency during CFS-induced freezing behavior. These results suggested that endogenous 5-HT inhibited the firing activity of hippocampal CA1 pyramidal neurons during CFS-induced freezing behavior mainly through stimulating 5-HT1A receptors.