Long-term Outcomes of People With DSM Psychotic Disorder NOS

The Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV diagnostic category "Psychotic disorder not otherwise specified" (PNOS) is seldom investigated, and we lack knowledge about long-term outcomes. We examined long-term symptom severity, global functioning, remission/recovery rates, and diagnostic stability after the first treatment for PNOS.

Participants with first-treatment PNOS (n = 32) were reassessed with structured interviews after 7 to 10 years. The sample also included narrow schizophrenia spectrum disorders (SSD, n = 94) and psychotic bipolar disorders (PBD, n = 54). Symptomatic remission was defined based on the Remission in Schizophrenia Working Group criteria. Clinical recovery was defined as meeting the criteria for symptomatic remission and having adequate functioning for the last 12 months.

Participants with baseline PNOS or PBD had lower symptom severity and better global functioning at follow-up than those with SSD. More participants with PNOS and PBD were in symptomatic remission and clinical recovery compared to participants with SSD. Seventeen (53%) PNOS participants retained the diagnosis, while 15 participants were diagnosed with either SSD (22%), affective disorders (19%), or substance-induced psychotic disorders (6%). Those rediagnosed with SSD did not differ from the other PNOS participants regarding baseline clinical characteristics.

Long-term outcomes are more favorable in PNOS and PBD than in SSD. Our findings confirm diagnostic instability but also stability for a subgroup of participants with PNOS. However, it is challenging to predict diagnostic outcomes of PNOS based on clinical characteristics at first treatment.