Premorbid Functioning Patterns and Post-Illness Psychosocial Functioning in the Early Stages of Psychosis

Background and Purpose: Schizophrenia is a chronic, debilitating illness with significant heterogeneity of onset, illness course, and outcome. Although affecting just 1% of the population, disability expenditures from schizophrenia rank 11^th of all health disorders internationally. Much of this disability results from severe psychosocial impairments. These functional impairments commonly persist even after psychosis symptoms are successfully treated. Premorbid adjustment, or the developmental performance prior to the initial psychotic episode, is a robust prognostic indicator for many clinical outcomes in psychosis and may inform long-term psychosocial outcomes in psychosis but these relationships are understudied. This investigation set out to explore the relationships of premorbid social and academic performance throughout development to post-onset psychosocial functioning in the early stages of psychosis, the precursor to schizophrenia.

Methods: One hundred and four non-affective early psychosis patients were recruited from the inpatient unit and outpatient clinics at Vanderbilt University Medical Center. Patients were assessed for psychiatric diagnoses, premorbid functioning using the Premorbid Adjustment Scale (PAS), and post-onset psychosocial functioning using the Personal and Social Performance scale (PSP) and Quality of Life Scale (QLS). Four variables were created to characterize the premorbid period using trajectory and domain of premorbid functioning from the PAS: social and academic intercept (initial starting level), social and academic slope (change in performance over development). Global psychosocial functioning was operationalized as the 0 to 100 score from the PSP and social and occupational functioning scores were created from sub-scales of the QLS. Relationships between premorbid variables and post-onset psychosocial functioning for social, occupational, and global functioning were analyzed with linear regression models.

Results: As hypothesized, post-onset global psychosocial functioning at study entry was significantly predicted by the premorbid change in social performance over time and initial academic level in childhood. Post-onset social functioning was significantly associated with both the premorbid initial starting level and change over time for social performance. Contrary to our hypotheses, the occupational functioning model was not significantly predicted by premorbid variables.

Conclusions and Implications: These findings demonstrate the informative role of premorbid functioning in relationship to subsequent psychosocial functioning in the early stages of psychosis, particularly for global and social functioning. This antecedent, pre-illness information provides valuable predictive power for functional outcome trajectories in psychosis. Clinical practice applications from these findings may include creating individually tailored psychosocial rehabilitation interventions which take into account each patient’s strengths or challenges noted from PAS patterns. By using the individual’s highest level of functioning before the onset, who the person was before becoming ill, to set more specific treatment goals may result in better suited rehabilitative efforts to promote recovery from psychosis. Future investigations should focus on establishing a longitudinal prediction of functioning at more distal follow-up along the course of psychosis to bolster support for this method and developing more individually tailored psychosocial rehabilitation interventions in early psychosis and schizophrenia.