Changes in Stereotypical Behavior Following Chlorpromazine Termination: Polypharmcy Effects on Response Class Membership.

Objectives: A paucity of information exists relating to the possible biological and environmental interactions influencing the occurrence of stereotypical behavior. In particular, there is limited research on the effects of psychotropic medication use on stereotypy presentation in individuals diagnosed with developmental disabilities such as intellectual disability and autism spectrum disorder.

Methods: We studied the stereotypy of a man with autism spectrum disorder and intellectual disability across 2 years. The topographies of stereotypical behavior included walking in circles, head tapping, arm flinging, and object stereotypy. These behaviors were observed weekly while the participant received daily dosages of 25 mg of chlorpromazine, 1.5 mg of lorazepam, and 2,500 mg of divalproex. At Week 75, chlorpromazine was discontinued while the other drugs and dosages were maintained.

Results: We observed a statistically significant decrease in walking in circles, but no changes in the other topographies of stereotypy.

Conclusions: The results suggest that the gross motor activity was differentially affected by the chlorpromazine discontinuation and also suggests that alterations in dopamine receptor binding may have selectively influenced changes in stereotypical responding.