The American journal of psychiatry
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Comparative Study
Impact of sleep deprivation and subsequent recovery sleep on cortisol in unmedicated depressed patients.
One night of sleep deprivation induces a transient improvement in about 60% of depressed patients. Since depression is associated with abnormalities of the hypothalamic-pituitary-adrenal (HPA) axis, the authors measured cortisol secretion before, during, and after therapeutic sleep deprivation for 1 night. ⋯ This study demonstrated a significant stimulatory effect of 1 night of sleep deprivation on the HPA axis in unmedicated depressed patients. The results suggest that the short-term effects of antidepressant treatments on the HPA axis may differ from their long-term effects. A higher cortisol level after sleep deprivation might transiently improve negative feedback to the hypothalamus or interact with other neurotransmitter systems, thus mediating or contributing to the clinical response. The fast return to baseline values coincides with the short clinical effect.
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Multicenter Study Comparative Study
The mood spectrum in unipolar and bipolar disorder: arguments for a unitary approach.
This study examined the extent to which individuals with a lifetime diagnosis of recurrent unipolar disorder endorse experiencing manic/hypomanic symptoms over their lifetimes and compared their reports with those of patients with bipolar I disorder. ⋯ The presence of a significant number of manic/hypomanic items in patients with recurrent unipolar depression seems to challenge the traditional unipolar-bipolar dichotomy and bridge the gap between these two categories of mood disorders. The authors argue that their mood spectrum approach is useful in making a more accurate diagnostic evaluation in patients with mood disorders.
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Comparative Study
Event-related fMRI of frontotemporal activity during word encoding and recognition in schizophrenia.
Neuropsychological studies have demonstrated verbal episodic memory deficits in schizophrenia during word encoding and retrieval. This study examined neural substrates of memory in an analysis that controlled for successful retrieval. ⋯ The pattern of prefrontal cortex underactivation and parahippocampal overactivation in the patients suggests that functional connectivity of dorsolateral prefrontal and temporal-limbic structures is disrupted by schizophrenia. This disruption may be reflected in the memory strategies of patients with schizophrenia, which include reliance on rote rehearsal rather than associative semantic processing.