Premorbid behavioral and intellectual functioning in schizophrenia patients with poor response to treatment with antipsychotic drugs

Introduction: Approximately one third of schizophrenia patients show partial or no response to pharmacotherapy. Despite intensive investigations, the phenomenological and biological characteristics of such patients are far from elucidated. This study examined the premorbid behavioral and intellectual functioning of schizophrenia patients who showed poor response to antipsychotic treatment. Method: One hundred twenty-nine schizophrenia patients who showed poor response to treatment were ascertained from a national register and matched by gender, age and education to 129 patients who showed adequate response. The groups were compared on premorbid measures of behavioral and intellectual functions. Results: As a group, treatment-resistant male patients had significantly lower (worse) social functioning [p = 0.002], and individual autonomy [p < 0.0001] scores before the onset of the illness compared to treatment non-resistant patients. Male and female treatment-resistant patients did not differ from non-resistant patients in premorbid intellectual functioning [p > 0.1]. Conclusions: Low premorbid social functioning and individual autonomy, but not intellectual functioning, could serve as predictors of poor treatment response in schizophrenia.