Objective: while negative symptoms are associated with poor functioning and quality of life, pharmacological managements have imperfect effects on negative symptoms and may even contribute to or exacerbate secondary negative symptoms. Meanwhile, pharmacotherapy of negative symptoms by add-on antidepressants, too, has produced unpredictable results. So, in the present study, some of the indigenous methodical published studies have been the subject of a new met-analysis, to evaluate the effectiveness of adjunctive psychotropic drugs on deficit syndrome of schizophrenia.
Methods: Twelve randomized placebo-control trials (n=433), which had been accomplished during the last fourteen years in Razi psychiatric hospital, had been selected for the present analysis. As a shared protocol, all the samples had been chosen among the chronic male inpatients, meeting the diagnosis of schizophrenia according to Diagnostic and Statistical Manual of Mental Disorders, 4th edition, text revision, who had been entered into parallel group, double-blind studies for random assignment to a psychotropic medication (like antidepressant, benzodiazepine, psycho-stimulant, Acetyl-cholinesterase inhibitors) or placebo plus their current antipsychotic. Scale for Assessment of Negative Symptoms (SANS) was used as the primary outcome measure in these experiments for assessment of negative symptoms. Response, too, was defined as a reduction of ⩾20% in the severity of SANS score (total and/or subscales).
Results: While the heterogeneity of the present meta-analysis was intermediate, the combined effect size of the abovementioned studies has shown a significant influence with respect to the effectiveness of psychotropic drugs on negative symptoms of schizophrenia (OR = 5.40, CI= 2.69- 10.85, z= 5.32, p<0.000) .
Similar results, as well, could be found in connection with various negative symptoms. In this regard, ‘Anhedonia-Asociality’ showed the best “Combined Effect Size”, followed by ‘Affective Blunting’, ‘Avolitio-Apathy’, ‘Attention Deficit’, and last of all ‘Alogia’. Heterogeneity of all the said analysis was insignificant and therefore appropriate.
Conclusion: According to the findings, psychotropic drugs, as add-on medications, have valuable effects with respect to amelioration of deficit syndrome of schizophrenia.