Abstract
The authors report the clinical histories of two adults with profound mental retardation, features of rapid cycling bipolar disorder, and periodic maladaptive behaviour. In each case, primary features of mania and depression were identified, operationally defined and measured with an ongoing data system, which was used to track SIB and aggression. In the first case, data analysis across days showed that 1-week episodes of depressive features alternated with 2-week episodes of manic features and that SIB was only associated with the depressive features. In the second case, episodes of manic and depressive features alternated every few days, and aggression was only associated with the manic features. These cases suggest that severe behaviour problems can be a state-dependent phenomenon of bipolar disorder. The behaviour monitoring system provided an objective methodology for aiding in the diagnosis of bipolar disorder with profoundly handicapped adults.