Recovery from neuroendocrinological abnormalities and frontal hypoperfusion after remission in a case with rapid cycling bipolar disorder

Abstract  A 51-year-old Japanese woman who had been suffering from a rapid cycling affective disorder (RCAD) for 24 years responded to combined clonazepam and carbamazepine therapy. Before remission, she showed neuroendocrinological and neuroimaging abnormalities such as subclinical hypothyroidism with exaggerated response to thyrotropin releasing hormone (TRH) injection, non-suppression on the dexamethasone suppression test (DST) and hypofrontality in cerebral blood flow. Her symptoms improved remarkably soon after adjunctive clonazepam treatment. After remission, her biological markers gradually returned to normal. First, subclinical hypothyroidism improved 2 months after remission. Next, hypofrontality disappeared 18 months later. Furthermore, non-suppression on the DST normalized 24 months later. The normalization of biologcal markers with apparent recovery from RCAD suggests a decreased risk of relapse into mood disorder. These findings reiterate the importance of following-up on the biological markers in RCAD for years after remission.