Data on schizotypy and affective scales are gender and education dependent--study in the Northern Finland 1966 Birth Cohort.

We present psychometric properties and normative data by gender and educational level in scales related to schizotypy and affective disorders in a large population-based adult sample. As part of the 31-year follow-up survey of the Northern Finland 1966 Birth Cohort; Bipolar II scale (BIP2), Hypomanic Personality Scale (HPS), Physical Anhedonia Scale (PAS), Social Anhedonia Scale (SAS), Perceptual Aberration Scale (PER) and Schizoidia Scale (SCHD) were filled in by 4928 subjects. In total sample mean scores were: BIP2 10.59 (3.80), HPS 11.26 (7.03), PAS 14.99 (S.D. 7.03), SAS 9.44 (5.52), PER 2.35 (3.26) and SCHD 2.56 (1.42). Men scored higher (had more psychopathological symptoms) in PAS and SAS (P<0.001), and in BIP2 (P=0.02). Women had higher scores in SCHD, HPS and PER (P<0.001). Participants with a lower level of education scored higher in all scales; differences were largest in BIP2, PAS and SAS (ES>0.5,P<0.001). The gender and education differences were moderate or large in all the included scales. These differences should be taken into account when considering normal values in these scales. The findings indicate that commonly used student samples are likely to be biased when compared to community based samples. Copyright 2008 Elsevier Ltd. All rights reserved.