[Biological findings in rapid cycling syndromes]

A subgroup of bipolar affective psychoses is characterized as rapid cycling affective disorder with at least four affective episodes resp. two bipolar cycles per year, including cycles of 48 hours ("ultra-rapid-cycling"). We show that rapid cycling-syndromes but not ultra rapid cycling-syndromes are comparable to traditional cyclothymic psychoses with respect to psychopathology, sex distribution, age of onset, REM sleep parameters and neuroendocrinological findings. Rapid cycling-syndromes exhibit acute switches, a peculiar coherence of course and intensity and a atypical combination of depression and hypersomnia. Ultra rapid cycling-syndromes are psychopathologically closely linked to some hypo- und hyperphases of endogenous psychoses. Like seen through a window they represent phenomena of syndromal shifting and can be related to organic dienzephaloses. They verify experiences of the sleep deprivation therapy that show the most sensitive night time for shifting being that between 1 and 3 o'clock a.m. The meaning of the drug induced rapid cycling may be overrated. The differential diagnosis includes various symptomatic affective psychoses as well as catatonic schizophrenic syndromes. Pathogenetic ideas discuss disorders of the pituitary dienzephalic regulation.