Differences in Real-world Functioning Between Adoptees With High or Low Risk for Schizophrenia Spectrum Disorders-The Finnish Adoptive Family Study of Schizophrenia.

Background and hypothesis: Schizophrenia spectrum disorders are known to affect the patient's functional performance. The functioning of those who are at familial risk for these disorders is less well understood. In this study, we compared the real-world functioning of adoptees with a genetic high-risk (HR) for schizophrenia spectrum disorders with adoptees without this risk (low-risk, LR). We hypothesized that the HR-group would have more difficulties in real-world functioning compared to the LR-group.

Study design: The data were based on the Finnish Adoptive Family Study of Schizophrenia project. The study sample included 127 HR- and 130 LR-adoptees. An interview-based method, Strauss-Carpenter Level of Function (SCLF)-scale, was used to measure functional performance in a setup of adoptees living in comparable adoptive families. The SCLF-scale comprises domains for function, symptoms, social contacts, and work. The Structured Interview of Schizotypy was utilized in assessments of possible schizotypal traits of the HR- and LR-adoptees.

Study results: No significant differences in the real-world functioning in total scores or scores of any SCLF domains were observed between HR- and LR-adoptees. Of single SCLF items, the HR-adoptees were characterized as being less likely to have achieved formal education and the LR-adoptees needed more help with their own basic needs.

Conclusions: No differences were found in the real-world functioning between HR- and LR-populations. This indicates that the real-world functioning does not express one's genetic risk for schizophrenia spectrum disorders. Our findings highlight the importance of considering environmental factors when comparing genetically different groups.