Associations between schizotypal features and indicators of neurological and morphological abnormalities.

Objective: Limited research suggests that subtle neurological and morphological abnormalities that have been documented in patients with schizophrenia also may be associated with schizotypal traits in non-psychiatric samples. Based on the notion that neurological soft signs (NSS) may mark a genetic diathesis, this study hypothesized that NSS scores would be related to the level of schizotypy in relatives of schizophrenia patients and in controls. Additionally, associations between MPA scores and schizotypy were explored in these two groups.

Method: Twenty-six first-degree relatives of schizophrenia patients and 38 controls with no personal or family history of psychosis were assessed for schizotypy using the Structured Clinical Interview for DSM-IV Axis II Disorders schizotypal personality disorder module, as well as the self-administered Schizotypal Personality Questionnaire. The Neurological Evaluation Scale and a structured examination for MPAs also were administered.

Results: Mean schizotypy scores did not differ between relatives and controls. Both NSS and MPAs were associated with the level of interviewer-assessed schizotypal features in controls but not in relatives of patients with schizophrenia. NSS and MPAs were not associated with self-reported schizotypy in either group.

Conclusions: These findings demonstrate that both NSS and MPAs are associated with interview-based schizotypal traits, at least in non-psychiatric participants. Future research should seek to replicate these results in other samples of relatives and controls.