Exploration of Treatment-Resistant Schizophrenia Subtypes Based on a Survey of 204 US Psychiatrists.

objectiveTo explore and describe potential subgroups within the treatment-resistant schizophrenia (TRS) population, using data from a survey of US psychiatrists.

methodsPsychiatrists completed an online survey of demographic/clinical characteristics and treatment history for two of their patients with TRS. Patients were stratified according to number of suicide attempts, number of hospitalizations, employment status, and TRS onset time frame.

resultsOf the 408 patients with TRS described by psychiatrists, 37.5% had ≥1 suicide attempt, 78.9% had ≥2 hospitalizations, 74.5% were unemployed, 45.0% had TRS onset within 5 years of first treatment (a further 8.0% had TRS from first treatment), and 31.5% had TRS onset after 5 years (15.5% unknown). Patients with ≥1 (vs 0) suicide attempts had statistically significantly more psychiatric (3.6 vs 2.2) and physical (2.2 vs 1.6) comorbidities. Patients with ≥2 (vs ≤1) hospitalizations were statistically significantly more likely to have hallucinations, conceptual disorganization, social withdrawal, and cognitive dysfunction, and had more psychiatric (3.0 vs 1.9) and physical (2.0 vs 1.1) comorbidities. Unemployed (vs employed) patients were statistically significantly more likely to have delusions, hallucinations, blunted affect, social withdrawal, and cognitive dysfunction, and had more psychiatric (2.9 vs 2.3) and physical (2.1 vs 1.2) comorbidities. Patients with TRS onset ≤5 (vs >5) years were statistically significantly younger (35.0 vs 43.7 years), less likely to have hallucinations and social withdrawal, and had fewer psychiatric (2.6 vs 3.3) and physical (1.7 vs 2.3) comorbidities.

conclusionsGreater clinical burden in TRS is associated with greater illness severity and chronicity markers, suggesting a dimensional gradient from non-TRS to mild-moderate and more severe forms of TRS. Time to onset of TRS may have implications for outcomes, with data indicating greater burden in those with late-onset TRS. Accumulation of illness over time may be more important than time to onset.