The prognosis of schizophrenia: A systematic review and meta-analysis with meta-regression of 20-year follow-up studies

Objective: The aim was to examine the general outcome of schizophrenia after 20 years or more.

Methods: Using the PRISMA guidelines, we conducted a systematic review and meta-analysis with meta-regression on long-term follow-up studies of schizophrenia up until April 21, 2021. We included prospective studies with at least 20 years of follow-up on patients with a diagnosis of schizophrenia, and the studies had to include face-to-face clinical evaluation. We examined outcome in three nested groups: 'recovery', 'good or better' (including also 'recovery'), and 'moderate or better' (including also 'recovery' and 'good or better'). We used random-effects meta-analysis and meta-regression to examine mean estimates and possible moderators.

Results: We identified 1089 records, which were screened by two independent researchers. 14 prospective studies (1991 patients) published between 1978 and 2020 were found eligible. The studies used a range of different scales and definitions for outcome, and some used the same definitions for different outcomes. To compare outcome across studies, we designed and applied a unified template for outcome definitions and cutoffs, based on earlier studies' recommendations. Our meta-analysis found that 24.2 % had 'recovered' (n = 246, CI: 20.3-28.0 %), 35.5 % had a 'good or better' outcome (n = 766, CI: 26.0-45.0%), and 59.7% had 'moderate or better' outcome (n = 1139, CI: 49.3-70.1 %).

Conclusions: The results contribute to debunk the myth that schizophrenia inevitably has a deteriorating course. Recovery is certainly possible. Schizophrenia remains, however, a severe and complex mental disorder, exhibiting a limited change in prognosis despite >100 years of research and efforts to improve treatment.