Longitudinal patterns of social functioning and conversion to psychosis in subjects at ultra-high risk

Impaired social functioning is one of the defining features of patients with schizophrenia and subjects at ultra-high risk (UHR) for psychosis. This prospective study aimed to investigate the course of social dysfunction in UHR subjects and to examine its relationship with later conversion to psychosis. The effect of pharmacotherapy on the course of social dysfunction was also examined.

A total of 57 UHR subjects and 58 healthy controls participated in this study. The Social Functioning Scale (SFS) was used to assess social functioning of UHR subjects at baseline and at the 1 year follow up. The changes in social functioning of UHR subjects have been examined to compare the social functioning of those who later converted to psychosis ('converters') with those who did not ('non-converters'). The effect of pharmacotherapy on longitudinal change in social functioning was also evaluated.

Subjects at UHR for psychosis showed more impaired social functioning at baseline than did healthy controls. Moreover, the course of social dysfunction of the converter and non-converter groups differed during the 1 year follow up period. The converters showed decreases in SFS average (F (1,32) = 7.85, p = 0.009) and interpersonal behaviour (F (1,32) = 10.43, p = 0.003) scores over time, whereas the non-converters showed increased scores. Additionally, we found that pharmacological treatment was associated with increased prosocial activities score (F (1,32) = 4.66, p = 0.038).

We found that the social functioning of converters was impaired before the onset of the psychosis and further declined during the at-risk phase. A series of social functioning indices in the longitudinal course may be helpful in predicting conversion to psychosis in subjects at UHR. Appropriate pharmacotherapy can offer clinical benefits by improving social functioning in UHR individuals.