Predictors of Community Functioning in Schizophrenia and Substance Use Disorder Patients

Community functioning is a broad term that encompasses various ‘real world’ measures of disability among schizophrenia patients.
It includes outcomes such as independent living, social competence and behavioural problems—all of which are priorities for
treatment among schizophrenia patients, mental health care providers, and family members. An important goal for rehabilitation
programs is to identify predictors of community functioning which, in turn, could be used as targets for intervention. The
present case–control study examined socio-demographic and substance use disorder (SUD) variables as well as psychiatric, extrapyramidal,
and cognitive symptoms as predictors of community functioning in schizophrenia patients with (DD patients; n = 31) and without
comorbid SUDs (SCZ patients; n = 31), and non-psychosis substance abusers (SUD patients; n = 39). Psychiatric and extrapyramidal
symptoms were evaluated with the Positive and Negative Syndrome Scale, the Calgary Depression Scale for Schizophrenia and
the Extrapyramidal Symptoms Rating Scale. Cognition was evaluated using the Cambridge Neuropsychological Test Automated Battery
(speed of processing, explicit and working memory). In SCZ patients, community functioning was predicted by explicit memory
performance. In DD patients, community functioning was predicted by substance abuse, depression and speed of processing. In
SUD patients, community functioning was predicted by substance abuse, positive symptoms and education. Our results suggest
that cognition should be among the top treatment priorities in SCZ patients, whereas the key treatment targets in DD patients
should be substance abuse and depression. Future studies will need to replicate the current findings, using prospective research
designs.