Background: Investigating the relationship between premorbid functioning and treatment response in schizophrenia is relevant to understanding the illness and predicting treatment outcomes.
Aims: To examine the relationship between premorbid characteristics and treatment response of people with recent-onset schizophrenia.
Method: Data came from a large, double-blind trial of recent-onset psychosis treated with a flexible dose of risperidone or haloperidol. Median treatment length was 206 days. Premorbid functioning was categorised using the Cannon-Spoor Premorbid Adjustment Scale.
Results: There were significant differences between the premorbid groups on change on the Positive and Negative Syndrome Scale, Clinical Global Impression severity and cognitive functioning and Extrapyramidal Symptoms Rating Scale. Patients in the ;stable-good' premorbid group (n = 251) improved more than those in the'stable-poor' (n = 198) and 'declining' (n = 81) groups. The ;stable-good' group received the lowest doses of antipsychotic and had the least extrapyramidal symptoms. Patients in the 'declining' group had the highest dosages and the most extrapyramidal symptoms.
Conclusions: In first-episode psychosis good premorbid functioning is associated with better response to treatment and fewer extrapyramidal symptoms.