Effects of cognitive treatment in psychiatric rehabilitation. Improvement of cognitive function in schizophrenic patients receiving clozapine or zotepine: results from a double-blind study.
Ninety subjects with severe and disabling psychiatric conditions, predominantly schizophrenia, participated in a controlled-outcome trial of the cognitive component of Integrated Psychological Therapy (IPT), a group-therapy modality intended to reestablish basic neurocognitive functions. The cognitive therapy was delivered to subjects in the experimental condition during intensive 6-month treatment periods. Control subjects received supportive group therapy. Before, during, and after the intensive treatment period, all subjects received an enriched regimen of comprehensive psychiatric rehabilitation, including social and living skills training, optimal pharmacotherapy, occupational therapy, and milieu-based behavioral treatment. IPT subjects showed incrementally greater gains compared with controls on the primary outcome measure, the Assessment of Interpersonal Problem-Solving Skills, suggesting that procedures that target cognitive impairments of schizophrenia spectrum disorders can enhance patients' response to standard psychiatric rehabilitation, at least in the short term, in the domain of social competence. There was equivocal evidence for greater improvement in the experimental condition on the Brief Psychiatric Rating Scale disorganization factor and strong evidence for greater improvement on a laboratory measure of attentional processing. There was significant improvement in both conditions on measures of attention, memory, and executive functioning, providing support for the hypothesis that therapeutic procedures that target impaired cognition enhance response to conventional psychiatric rehabilitation modalities over a 6-month timeframe. Clinical interest in the so-called atypical antipsychotics currently focuses on the possibility of improving the negative symptoms of schizophrenia and the cognitive dysfunction associated with the disease. While clozapine has been shown to be effective in this respect, no data are available on zotepine. We report on a double-blind randomized study designed to evaluate the impact of zotepine and clozapine on cognitive dysfunction in schizophrenia. Cognitive function was operationalized by a maze test in which patients traversed computer-displayed mazes of increasing complexity. Passage time, route, and motor errors were evaluated. 25 schizophrenic (DSM-IIIR) patients were included in each group. After washout, they were randomized on zotepine or clozapine and given up to 450 mg of substance each. Patients were followed for six weeks and evaluated weekly. We report on a subsample of 26 patients matched for baseline BPRS, SANS, and age. 13 matched healthy persons were recruited as controls. ANOVA with group and course over time as factors was used for analysis. Both clozapine and zotepine achieved a highly significant decrease in overall symptoms (BPRS) and negative symptoms (SANS). Zotepine and clozapine were equally effective. In the maze tests, motor errors in simple mazes were stable over time and differentiated schizophrenics from controls as a "trait" marker. In passage time and maze route, schizophrenics performed worse than controls. An improvement by medication was evident in both medication groups, but was more pronounced in the zotepine-treated group. The study confirms previous results on the efficacy of clozapine and zotepine in treating negative symptoms of schizophrenia. The data presented show for the first time that zotepine is efficacious in improving cognitive dysfunction, confirming this substance's value as an atypical antipsychotic.
Data are inconclusive and provide no evidence for or against cognitive rehabilitation as a treatment for schizophrenia.