Influential protocols in the treatment of schizophrenia recommend the use of antipsychotics in monotherapy, although combination is common in clinical practice.

To compare cognitive performance of patients with schizophrenia treated by antipsychotic monotherapy or polytherapy; secondly, to analyze clinical and sociodemographic differences.

Ninety-eight outpatients between 18 and 65 years, diagnosed with schizophrenia, based on the DSM-V were recruited. Seventy were in monotherapy and 28 in antipsychotic combination. Patients with comorbidity, moderate to severe motor impregnation, abuse-substance dependence or serious somatic illness were excluded. Both groups were compared in sociodemographic, clinical and cognitive measures: PANSS scale, short Akathisia Scale Simpson-Angus Scale, State-Trait Anxiety Inventory (STAI), face emotion recognition (FEIT) and global Functioning (GAF), speed processing - through the Trail Making Test, parte A, subtest of symbol coding of the Brief Assessment of Cognition in Schizophrenia (BACS) and Verbal fluency (animals)- and sustained attention (SA)–through the Continuous Performance Test (CPT).

Both groups showed similar age, gender, number of hospitalizations, score in STAI-Trait, STAI-State, ANGUS, GAF, TMT-A, verbal fluency and face emotion recognition. Patients in politherapy had more years of evolution (P 0.047), higher score in positive PANSS (P 0.007), negative PANSS (P 0.008), general PANSS (P 0.001); they showed more detection errors in the CPT (P 0008), and a trend towards less processing speed through the symbol coding (P 0.063), compared to patients in monotherapy.

Antipsychotic polipharmacy is associated with an impairment in sustained attention in patients with schizophrenia.

The authors have not supplied their declaration of competing interest.