Disentangling cognitive inflexibility in major depressive disorder: A transcranial direct current stimulation study.

BACKGROUND: Cognitive dysfunction is a persistent residual symptom in major depressive disorders (MDDs) that hinders social and occupational recovery. Cognitive inflexibility is a typical cognitive dysfunction in MDD and refers to difficulty in switching tasks, which requires two subcomponents: forgetting an old task and adapting to a new one. Here, we aimed to disentangle the subcomponents of cognitive inflexibility in MDD and investigate whether they can be improved by transcranial direct current stimulation (tDCS) on the prefrontal cortex. METHODS: The current study included 20 patients with MDD (seven females) and 22 age-matched healthy controls (HCs) (seven females). The participants received anodal tDCS on either the dorsomedial prefrontal cortex (DMPFC) or dorsolateral prefrontal cortex (DLPFC) in a crossover design. Before and after the application of tDCS, the participants performed a modified Wisconsin Card Sorting Test, in which the task-switching rules were explicitly described and proactive interference from a previous task rule was occasionally released. RESULTS: We found that the behavioral cost of a task switch was increased in patients with MDD, but that of proactive interference was comparable between patients with MDD and HCs. The response time for anodal DMPFC tDCS was decreased compared with that for anodal tDCS on the DLPFC in MDD. CONCLUSIONS: These findings suggest that cognitive inflexibility in MDD is primarily explained by the difficulty to adapt to a new task and environment, and that tDCS on the DMPFC improves behavioral performance during cognitively demanding tasks that require conflict resolution.

The Comparative Effects of Risperidone Long-Acting Injection and Paliperidone Palmitate on Social Functioning in Schizophrenia: A 6-Month, Open-Label, Randomized Controlled Pilot Trial.

PURPOSE: The aim of this study was to compare the effects of risperidone long-acting injection (RLAI) and paliperidone palmitate (PP) on non-acute-phase social functioning in patients with schizophrenia. PATIENTS AND METHODS: In this 6-month pilot, open-label, randomized controlled study, 30 patients with schizophrenia who had been treated with RLAI were randomly allocated to the RLAI continuation group or switched to the PP group. Patients were evaluated at baseline and 6 months with the Social Functioning Scale (SFS) as the primary outcome variable and University of California San Diego Performance-Based Skills Assessment Brief (UPSA-B), Social Emotional Cognition Task (SECT), Positive and Negative Syndrome Scale (PANSS), and Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) scores as secondary outcomes. RESULTS: At baseline, the two groups did not significantly differ in demographic or clinical features. The two groups did not differ in total score changes for the UPSA-B, the SECT, the PANSS, and the DIEPSS. However, the total scores and the two subscales of the SFS, i.e. independence-competence and independence-performance, were more improved in the PP group compared to the RLAI group (total scores, p = 0.038; competence, p = 0.001, and performance, p = 0.007, respectively). CONCLUSION: These results suggest that PP may improve the total social functioning, independent life competence, and performance as compared to the RLAI group. However, these results are preliminary and need independent replication in larger samples before any definitive statement can be made.

Cognitive function and risperidone long-acting injection vs. paliperidone palmitate in schizophrenia: a 6-month, open-label, randomized, pilot trial.

BACKGROUND: Recently, long-acting injection (LAI) of second-generation antipsychotics has become a valuable strategy for the treatment of schizophrenia. However, few studies have compared the effects of different LAI antipsychotics on cognitive functions so far. The present study aimed to compare the influence of risperidone LAIs (RLAI) and paliperidone palmitate LAIs (PP) on cognitive function in outpatients with schizophrenia. METHODS: In this 6-month, open-label, randomized, and controlled study, 30 patients with schizophrenia who were treated with RLAIs were randomly allocated to the RLAI-continued group or the PP group. At baseline and 6 months, the patients were evaluated using the Brief Assessment of Cognition in Schizophrenia (BACS) that was the primary outcome of the study. The Subjective Well-being under Neuroleptic drug treatment-Short form (SWNS), the Positive and Negative Syndrome Scale (PANSS), and the Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) scores were secondary outcome variables and they were tested at the same time points. RESULTS: The two groups did not differ in terms of PANSS, DIEPSS, or SWNS total score changes. However, the BACS score for the attention and processing speed item showed higher improvement in the PP group than the RLAI group (p = 0.039). CONCLUSIONS: The results of this preliminary study suggest that PPs may improve attention and processing speed more than RLAIs. Anyway, a replication in a larger and double-blind study is needed. TRIAL REGISTRATION: UMIN000014470 . Registered 10 July 2014.

Characteristics of persistent depression in the long-term: Randomized controlled trial and two-year observational study.

Major depressive disorder is a chronic condition that can recur and relapse. It would be clinically useful to know the patient background to predict the chronicity of depressive symptoms, and the change in diagnosis of bipolar disorder. This study included 197 patients enrolled in a six-week randomized controlled trial with a two-year follow-up. We conducted multiple logistic regression analyses to identify the clinical and sociodemographic characteristics associated with persistent depressive disorder (PDD), relapse, and changes in bipolar disorder diagnosis. The significantly correlated factors were residual symptoms, including insight, work and activity, and general somatic symptoms at week six. We could not identify any factors that contributed to relapse or change in the diagnosis of bipolar disorder. We found that the specific residual symptoms of acute treatment affected long-term treatment outcomes for depression. Attention should be paid to the residual symptoms of depression in the early stages of treatment, and measures should be considered to improve them. There are several limitations to this study, including the fact that PDD may exist among patients who discontinued treatment, treatment was not standardized during the study period, and adherence was confirmed verbally.

Non response at week 4 as clinically useful indicator for antidepressant combination in major depressive disorder. A sequential RCT.

We aimed to compare the efficacy and tolerability of mirtazapine versus SSRIs and to assess whether "non-response at week 4" may be a clinical indicator for combining mirtazapine and SSRIs for subsequent treatment. One-hundred fifty-four outpatients with MDD were randomized to receive mirtazapine or SSRIs in step I (4 weeks). Non-responders in step I were randomly assigned to either mirtazapine or SSRIs monotherapy or their combination in step IIa while responders in step I continued the same monotherapy in step IIb for 4 weeks. In step I, mirtazapine showed significantly faster improvement as shown by higher remission rate at week 2 with NNT = 8 compared to SSRIs. Somnolence rate was higher in mirtazapine and nausea rate was higher in SSRIs. In step IIa, combination therapy showed a more favorable time course than SSRIs monotherapy. For subjects taking SSRIs in step I, combination therapy showed significant better improvement in the Hamilton Depression Rating (HAM-D) score both at week 6 (p = 0.006) and 8 (p = 0.013) than SSRIs monotherapy. About 80% of responders at week 4 could reach remission at week 8 and 64% of non-responders could not reach remission at week 8 for patients who continued monotherapy. When mirtazapine was added on for SSRIs non-responders at week 4, the remission rate increased by 5% and HAM-D score improved by 4 points. While for mirtazapine non-responders, SSRIs add-on was not equally effective. Mirtazapine may provide a faster improvement and "non-response at week 4" may be indicator to mirtazapine add-on for patients receiving SSRIs.