Demographic moderators of the relationship between psychiatric diagnosis and functional capacity in people with serious mental illness.

Abstract

The UCSD Performance-based Skills Assessment-Brief (UPSA-B) is widely used to evaluate functional capacity in people with serious mental illness (SMI; schizophrenia/schizoaffective disorder [SZ], bipolar disorder [BD], major depressive disorder [MDD]). Previous research has not addressed diagnostic group differences on UPSA-B performance using demographically normed T-scores, nor has it probed whether this relationship is moderated by demographic factors (age, sex, racial/ethnic minority status, education). Participants were 153 outpatients with SMI (SZ n = 58; BD n = 37; MDD n = 58). We analyzed relationships among UPSA-B T-score, diagnostic group, demographic variables, and diagnostic group by demographic variable interactions. The model revealed a significant main effect of age, with younger participants outperforming older participants (F[1144]=12.26, p=.0006). There was a significant effect of diagnosis, with SZ participants performing significantly worse than those with BD and MDD (F[2144]=17.72, p<.0001). There was also a significant diagnosis by sex interaction (F[1144] = 9.10, p=.006) such that within MDD participants, women outperformed men. The diagnostic effect (lower scores in SZ compared with BD/MDD) is consistent with prior research. The age and sex effects were above and beyond the UPSA-B normative corrections generated in a non-psychiatric sample, suggesting an accelerated aging effect in a transdiagnostic SMI sample and a distinct functional disadvantage for men with MDD. When developing and implementing interventions for this population, particular attention should be paid to those living with schizophrenia and schizoaffective disorder, older adults with SMI, and men with MDD.