Former college students (n = 36) identified by high scores on the Hypomanic personality Scale (HYP; Eckblad & Chapman, 1986) were compared with control participants (n = 31) at a 13-year follow-up assessment. As hypothesized, the HYP group reported more bipolar disorders and major depressive episodes than the control group. The HYP group also exceeded the control group on the severity of psychotic-like experiences, symptoms of borderline personality disorder, and rates of substance use disorders. HYP group members with elevated scores on the Impulsive-Nonconformity Scale (Chapman et al., 1984) experienced greater rates of bipolar mood disorders, poorer overall adjustment, and higher rates of arrest than the remaining HYP or control participants.

The predictive validities of several indicators of psychosis proneness were evaluated in a 10-year longitudinal study (N = 508). As hypothesized, high scorers on the Perceptual Aberration Scale, Magical Ideation Scale, or both (n = 182), especially those who initially reported psychoticlike experiences of at least moderate deviance, exceeded control subjects (n = 153) on psychoses (revised 3rd edition of the Diagnostic and Statistical Manual of Mental Disorders), psychotic relatives, schizotypal symptoms, and psychoticlike experiences at follow up. Ss who initially scored high on the Magical Ideation Scale and above the mean on the Social Anhedonia Scale were especially deviant. The Physical Anhedonia Scale and the Impulsive Nonconformity Scale were not effective predictors of psychosis proneness.