Heterogeneity and the longitudinal recovery of functioning during inpatient psychiatric rehabilitation for treatment-refractory severe mental illness

Introduction. Few studies adequately capture the heterogeneity of severe mental illness (SMI) in recovery outcomes. In this study, we examine the between-person and within-person variance in the longitudinal recovery of key functional domains during a comprehensive inpatient psychiatric rehabilitation program for a severe, treatment-refractory population with SMI. Method. We reviewed clinical assessment data collected over 10 years from an inpatient psychiatric rehabilitation program in the Midwestern United States. Multilevel modeling techniques were applied to examine the between-person and within-person variance in baseline functioning, rates of change, and recovery of social functioning, neurocognition, social cognition, and the reduction of psychiatric symptoms in participants with schizophrenia-spectrum disorders (N=180) over a 12-month period. Results. After considering heterogeneous features at admission, significant overall improvement was evident in social functioning, neurocognition, and psychiatric symptoms. The recovery of social cognition improved at different rates across individuals, and there was an overall improvement in this domain over time. Discussion. SMI is characterized by significant heterogeneity in the recovery of functioning. Despite the between-person and within-person variance at baseline and over time, individualized comprehensive psychiatric rehabilitation can effectively enable the most disabled persons with SMI recover key domains of functioning.