Cognitive Functioning in Schizophrenia, Methamphetamine-induced Psychotic Disorder, and Healthy People: A Comparative Study

Background: Methamphetamine-induced psychotic disorder (MIP) cannot be easily differentiated from other psychotic disorders. Some studies have reported that patients with MIP and schizophrenia have differences in their cognitive functioning. We hypothesized that their performance would be different on neuropsychological tests which assess executive functions and visual memory. Materials and Methods: In a cross-sectional study, 30 patients with MIP, 31 patients with schizophrenia, and 31 healthy controls were assessed by Rey–Osterrieth complex figure (ROCF) test and visual search and attention test (VSAT). One-way analysis of variance was performed to compare the mean scores of tests. Tukey's HSD test was used for post hoc analysis. Results: Three groups had significant differences according to ROCF test (F = 15.76, P < 0.0001), VSAT (F = 39.78, P < 0.0001), left VSAT (F = 37.96, P < 0.0001), right VSAT (F = 40.40, P < 0.0001), and the time of the test administration (F = 3.26, P = 0.04). The post hoc analysis showed that the mean score of ROCF test and VSAT (total, right, and left) was significantly higher in the control group than in the other two groups. The time of administering the test in the control group was significantly shorter than in the MIP group (P < 0.03) and nonsignificantly shorter than in the schizophrenia group (P = 0.54). The mean score of right side VSAT was significantly higher in the MIP group than in the schizophrenia group. Conclusion: ROCF could not differentiate MIP from schizophrenia. The better performance of patients with MIP on right side VSAT that is reported in this and in the previous study needs to be reevaluated in more controlled studies

‎ Lamotrigine Augmentation versus Placebo in Serotonin ‎Reuptake Inhibitors-‎Resistant Obsessive-Compulsive Disorder: ‎A Randomized Controlled Trial

Objective: Serotonin reuptake inhibitors are frequently used in first-line treatments for patients ‎with obsessive-compulsive disorder. Nevertheless, many of these patients do not ‎respond well to initial therapy. The hypothesis of glutamatergic dysfunction in specific ‎brain regions has been proposed in the pathophysiology of obsessive-compulsive ‎disorder. This study was designed to evaluate the possible efficacy of lamotrigine, a ‎glutamatergic agent in Serotonin reuptake inhibitors-resistant patients with obsessive-‎compulsive disorder.‎ Method: This study was a 12-week, double blind, randomized, placebo-controlled trial of ‎adjunctive fixed-doses of lamotrigine (100 mg) to Serotonin reuptake inhibitors therapy ‎in obsessive-compulsive disorder. Eligible subjects who had a total Y-BOCS of 21 or ‎above were randomly assigned to receive adjunctive treatment with either lamotrigine ‎‎(n = 26), or placebo (n = 27). Response to lamotrigine was defined as clinical ‎improvement (>25% decrease in the total Y-BOCS score), which was administered at ‎weeks 0, 8 and 12.‎ Results: At the endpoint (week 12), significant differences were observed in obsession, ‎compulsion, and total Y-BOCS scores comparing lamotrigine to placebo (P = 0.01, ‎‎0.005 and 0.007 respectively). The mean reduction in obsession, compulsion and total ‎scores in lamotrigine group was about 4.15, 4.50 and 8.73, respectively. Similarly, the ‎mean reductions in the placebo group were 2.52, 2.56 and 5.07. Effect sizes for efficacy ‎measures were calculated by Cohen’s d, and it was calculated as 0.54 for the total ‎YBOCS.‎ Conclusion: Our findings provide evidence that this augmentation is well tolerated and may be an ‎effective strategy for patients with refractory obsessive-compulsive disorder.‎