Background: The rare cases of patients with 48-hour ultrarapid cycling allow close investigation of mood cycles in affective disorders, because rhythmic changes in psychopathologic state and biological parameters happen very precisely.
Method: A 67-year-old white man who had experienced bipolar 48-hour ultrarapid cycling (DSM-IV 296.80) for several years was studied without any medication and then again studied 4 weeks later during treatment with valproate (1800 mg/day).
Results: Objective and self ratings revealed pronounced manic states 1 day and depressed states the following day, which were found to be accompanied by rhythmic fluctuations in behavior and electroencephalographic parameters, blood cortisol and growth hormone levels (both elevated on depressive days), and urinary metanephrine (dopamine metabolite) and norepinephrine levels (both elevated on manic days). Using single photon emission computed tomography, regional blood flow in the left thalamus was lower than in the right thalamus on the manic day, while symmetric perfusion of the thalamus was found on the depressive day. Under valproate treatment, the patient remitted completely, and significant rhythmic changes in most of the biological parameters were no longer detectable.
Conclusion: The biological findings in this patient with bipolar 48-hour ultrarapid cycling, which correspond to those in other types of affective disorders, suggest that disturbances in the diencephalon-pituitary axis may be especially correlated to pathologic changes of mood.