Introduction: This study aims to compare the positive and negative symptoms of schizophrenia in patients who had psychotic symptoms more than one month after discontinuation of methamphetamine abuse. These factors were analyzed by the PANSS (Positive and Negative Syndrome Scale) questionnaire.
Materials and Methods: 60 participants were selected from patients referred to Iran Psychiatric Hospital with psychotic symptoms (delusions or hallucinations, disorganized behavior, and speech). The control group was 30 patients with schizophrenia based on a semi-structured interview according to DSM-IV-TR (SCID). 30 patients with the prolonged methamphetamine-induced psychotic disorder had been also placed in the case group. For both groups of patients, questionnaires of PANSS, BPRS, GAF was filled after obtaining the consent of the company. The scale scores were compared between groups. To evaluate the mean of PANSS, BPRS, and the GAF scores between the two groups we used the Mann-Whitney and the chi-square test.
Results: There was no significant difference in terms of positive and general pathology scores between two groups but the total score of negative symptoms in the schizophrenia group was significantly higher than the group of prolonged methamphetamine psychotic disorders (P = 0.034). Average scores of Uncooperativeness (0.013), Unusual thought content (0.004), Motor retardation (0.011), unusual thought content (0.002) and, Hostility (0.001) in schizophrenia were significantly higher than prolonged methamphetamine psychosis.
Conclusion: The results showed that most of the disturbances in patients with schizophrenia may be more influenced by the expression of cognitive disabilities in them compared to patients with methamphetamine psychosis. The difference in scores of negative symptoms suggesting that schizophrenia and prolonged methamphetamine psychotic disorder can be two different disorders.