Neurobiological findings in a patient with 48-hour manic-depressive cycles. A case study

Forty-eight-hour rapid cycling is a rare subclass of affective disorders an d entails a regular periodic change of moods. The following case study desc ribes the symptoms,therapy, and outcome of a patient suffering from daily s witching between mania and depression along with neurobiological findings c orrelated to the affective cycles. We found alternating reduction and prolo ngation of sleep duration during manic and depressive days as well as diffe rences in the amount of REM sleep. Cortisol secretion was regularly increas ed during depressive days. Regarding thyroid-stimulating hormone (TSH) secr etion, the circadian rhythm was absent on depressive days. Howewer, the glu cose metabolic rate as measured by positron emission tomography (PET) did n ot differ on manic and depressive days. The patient reached almost complete remission under treatment with lithium.