Background: Decline in social functioning occurs in individuals who later develop psychosis.
Aims: To investigate whether baseline differences in disability are present in those who do and those who do not make a transition to psychosis in a group clinically at high risk and whether disability is a risk factor for transition.
Method: Prospective multicentre, naturalistic field study with an 18-month follow-up period on 245 help-seeking individuals clinically at high risk. Disability was assessed with the Disability Assessment Schedule of the World Health Organization (WHODAS-II).
Results: At baseline, the transition group displayed significantly greater difficulties in making new friends (z = -3.40, P = 0.001), maintaining a friendship (z =-3.00, P = 0.003), dealing with people they do not know (z =-2.28, P = 0.023) and joining community activities (z =-2.0, P = 0.05) compared with the non-transition group. In Cox regression, difficulties in getting along with people significantly contributed to the prediction of transition to psychosis in our sample (β = 0.569, s.e. = 0.184, Wald = 9.548, P = 0.002, hazard ratio (HR) = 1.767, 95% CI 1.238-2.550).
Conclusions: Certain domains of social disability might contribute to the prediction of psychosis in a sample clinically at high risk.