Recurrent Premenstrual Decline in Serum Lithium Concentration: Clinical Correlates and Treatment Implications

A 16-year-old female adolescent who met DSM-III criteria for bipolar disorder, mixed with psychotic features, showed a clinical response to lithium carbonate, but experienced repeated deterioration in function whenever she entered the premenstrual phase of her menstrual cycle. This exacerbation in her affective psychosis coincided with a progressive fall in serum lithium concentration despite a constant oral regimen with which the patient was compliant. If the oral dose was prophylactically increased during the patient's luteal phase in order to compensate for the anticipated decline in serum concentration, and if the concentration could thereby be maintained at or above 1.1 mEq/L, then the premenstrual deterioration could be prevented.