Hypothesis: Schizotypal personality disorder patients will show cognitive improvements in 1) working memory 2) learning and memory 3) sustained attention 4) enhanced performance on the AX-CPT, N-back and Eriksen during pergolide treatment. There will be a significant diagnosis by drug administration of 0.3 mg of oral pergolide interaction for performance on the cognitive tasks, with the schizotypal personality disorder group demonstrating significantly improved peformance compared to the other personality disorder group after pergolide compared with placebo.

Design: Randomized, double-blind, crossover study of pergolide vs. placebo. Half of subjects receive pergolide for eight weeks; half of subjects receive placebo for four weeks followed by pergolide for four weeks.

Inclusion Criteria: DSM-IV criteria for Schizotypal Personality Disorder (or meets full criteria bar one) or another personality disorder and shows impairment on markers of cognitive functioning. Medically healthy, not abusing drugs or alcohol, is at least two weeks medication-free and does not have significant neurological disease.

-

Exclusion Criteria: DSM-IV or RDC criteria for Schizophrenia or any Schizophrenia-related psychotic disorder or for Bipolar Disorder. Any other Axis I disorders must be transient and preceded by the personality disorder diagnosis, which should be primarily responsible for subject's functional impairment.

-