Neuropsychological deficits are found in both schizophrenic patients and their relatives, and some studies have shown similar, but less severe, deficits in affective psychotic patients and their relatives. We set out to establish – whether schizophrenia spectrum personality traits are more common in the relatives of schizophrenic patients than relatives of affective psychotic patients; – what is the relationship between spectrum personality traits and neuropsychological deficits in these relatives.

Relatives were interviewed using the International Personality Disorder Examination (IPDE), and also completed the National Adult Reading Test (NART), the Trail Making Test (TMT: Parts A and B) and Thurstone's Verbal Fluency Test (TVFT). Spectrum personality traits were equally common in the 129 relatives of schizophrenic and 106 relatives of affective psychotic patients. Relatives of psychotic patients who themselves had high paranoid traits had lower NART scores than those without such personality traits (p=0.007);similarly, those with high schizoid personality traits took longer to complete the TMT, part B than those without such traits (p=0.0l); and relatives with high schizotypal traits generated significantly fewer words on the verbal fluency test than those without such traits (p=0.04).