The effects of acute serotonin challenge on executive planning in patients with obsessive-compulsive disorder (OCD), their first-degree relatives, and healthy controls

Comparison of Aripiprazole and Risperidone effectiveness in treating obsessive-compulsive disorder in patients with bipolar disorder: Double-blind, randomized clinical trial

Background

Obsessive-compulsive disorder (OCD) is a mental illness with a chronic coarse and waxing and waning of symptoms. Treatment of OCD in patients with bipolar disorder (BD) remains challenging.

Objectives

The present study aims to compare the safety and effectiveness of Risperidone and Aripiprazole as adjunctive therapy with valproate sodium, in treating mania, depression, and OCD in patients with comorbidity of OCD-BD.

Methods

This research is 3 phase, double-blind, randomized clinical trial, with a total number of 64 patients. The diagnostic psychiatrist clinical interview was based on diagnostic and statistical manual of mental disorders, 5th edition (DSM-5) criteria. For assessing severity of OCD, mania, and depression, Yale-Brown obsessive-compulsive scale (Y-BOCS), young mania rating scale (YMRS), and Hamilton depression rating scale (HAM-D) scores were used. Patients were randomly assigned to the two parallel groups. All patients in both group were received valproate sodium, one group was treated with Aripiprazole and the other group was treated with Risperidon as adjective therapy with valproate sodium.The SPSS software (version 22), χ 2 test, t-test, and analysis of variance with repeated measures were used to analyze the data.

Results

The dosage and time of both drugs were statistically significant in reducing the mean score of all three mentioned scales, but the effect of group was not statistically significant in HAM-D and YMRS scores, only in terms of OCD, the mean of the Y-BOCS score was significantly lower in the Aripiprazole group (p < 0.001). In relation to side effects, Risperidone induced statistically significant weight gain (p < 0.001) and Aripiprazole induced statistically significant sleep disturbance (p < 0.05).

Conclusions

Both Aripiprazole and Risperidone can be used effectively as adjunctive therapy with valproate sodium in treating OCD in patients with BD without any serious and life threatening adverse effect. Aripiprazole is more effective than Risperidone in treating OCD in BD.

Atypical action updating in a dynamic environment associated with adolescent obsessive-compulsive disorder

BACKGROUND

Computational research had determined that adults with obsessive-compulsive disorder (OCD) display heightened action updating in response to noise in the environment and neglect metacognitive information (such as confidence) when making decisions. These features are proposed to underlie patients' compulsions despite the knowledge they are irrational. Nonetheless, it is unclear whether this extends to adolescents with OCD as research in this population is lacking. Thus, this study aimed to investigate the interplay between action and confidence in adolescents with OCD.

METHODS

Twenty-seven adolescents with OCD and 46 controls completed a predictive-inference task, designed to probe how subjects' actions and confidence ratings fluctuate in response to unexpected outcomes. We investigated how subjects update actions in response to prediction errors (indexing mismatches between expectations and outcomes) and used parameters from a Bayesian model to predict how confidence and action evolve over time. Confidence-action association strength was assessed using a regression model. We also investigated the effects of serotonergic medication.

RESULTS

Adolescents with OCD showed significantly increased learning rates, particularly following small prediction errors. Results were driven primarily by unmedicated patients. Confidence ratings appeared equivalent between groups, although model-based analysis revealed that patients' confidence was less affected by prediction errors compared to controls. Patients and controls did not differ in the extent to which they updated actions and confidence in tandem.

CONCLUSIONS

Adolescents with OCD showed enhanced action adjustments, especially in the face of small prediction errors, consistent with previous research establishing 'just-right' compulsions, enhanced error-related negativity, and greater decision uncertainty in paediatric-OCD. These tendencies were ameliorated in patients receiving serotonergic medication, emphasising the importance of early intervention in preventing disorder-related cognitive deficits. Confidence ratings were equivalent between young patients and controls, mirroring findings in adult OCD research.

Alterations in metamemory capacity and neural correlates in a subtype of subjective cognitive decline

BACKGROUNDS

Subjective cognitive decline (SCD), one of the important clinical indicators for preclinical Alzheimer's disease (AD), is primarily defined as self-perceived cognitive decline without objective evidence for cognitive impairment. However, the accuracy of their self-evaluation of cognition is unclear. This study sought to investigate the capacity for self-evaluation of own cognitive performance in SCD by applying an objective metamemory paradigm.

METHODS

147 individuals with SCD were classified into four subgroups by their subjective feeling of worse performance than peers or not (P+/-) and whether they have objectively slight cognitive impairment compared to normative data (S+/-). Metamemory scores, the amplitude of the low-frequency fluctuation (ALFF), fractional low-frequency fluctuation amplitude (fALFF), and cortical thickness were compared among four subgroups. Partial correlations between neuropsychological scores and neuroimaging measures were examined, controlling for age, sex, and education years.

RESULTS

SCD S+P- showed the worst performance in short-term delayed recall and the worst metamemory performance, indicated by the highest value in the degree of confidence of short-term delayed recall (DOC-N4) and long-term cued recall (DOC-N6) and the worst value in relative accuracy of judgments of short-term delayed recall (ROJ-N4). ALFF values in the bilateral superior medial frontal and olfactory cortices and the left superior orbitofrontal gyrus cortex were significantly higher in SCD P- compared with SCD P+ groups (all P < 0.05, FWE-corrected, cluster-wise level). A significant S × P interaction effect in the left hippocampus and middle cingulate cortex was found for the fALFF signals (all P < 0.05, FWE-corrected, cluster-wise level). Significant interaction and main effects on cortical thickness were reported. The parahippocampal and posterior cingulate cortices were significantly decreased in SCD S+P- (all P < 0.05).

CONCLUSION

SCD S+P- showed the worst episodic memory performance, altered metamemory capacity (overconfidence and less accuracy of judgment), and altered neuroimaging measures, though they had feelings of similar performance with peers. Our results indicate that metamemory capacity is affected in a subtype of SCD with reduced cortical thickness and intensity of regional spontaneous activity in key areas for metamemory processing.

Flexible versus Fixed Spatial Self-Ordered Response Sequencing: Effects of Inactivation and Neurochemical Modulation of Ventrolateral Prefrontal Cortex

Previously, studies using human neuroimaging and excitotoxic lesions in non-human primate have demonstrated an important role of ventrolateral prefrontal cortex (vlPFC) in higher order cognitive functions such as cognitive flexibility and the planning of behavioral sequences. In the present experiments, we tested effects on performance of temporary inactivation (using GABA receptor agonists) and dopamine (DA) D2 and 5-HT2A-receptor (R) blockade of vlPFC via local intracerebral infusions in the marmoset. We trained common marmosets to perform spatial self-ordered sequencing tasks in which one cohort of animals performed two and three response sequences on a continuously varying spatial array of response options on a touch-sensitive screen. Inactivation of vlPFC produced a marked disruption of accuracy of sequencing which also exhibited significant error perseveration. There were somewhat contrasting effects of D2 and 5-HT2A-R blockade, with the former producing error perseveration on incorrect trials, though not significantly impairing accuracy overall, and the latter significantly impairing accuracy but not error perseveration. A second cohort of marmosets were directly compared on performance of fixed versus variable spatial arrays. Inactivation of vlPFC again impaired self-ordered sequencing, but only with varying, and not fixed spatial arrays, the latter leading to the consistent use of fewer, preferred sequences. These findings add to evidence that vlPFC is implicated in goal-directed behavior that requires higher-order response heuristics that can be applied flexibly over different (variable), as compared with fixed stimulus exemplars. They also show that dopaminergic and serotonergic chemomodulation has distinctive effects on such performance.SIGNIFICANCE STATEMENT This investigation employing local intracerebral infusions to inactivate the lateral prefrontal cortex (PFC) of the New World marmoset reveals the important role of this region in self-ordered response sequencing in variable but not fixed spatial arrays. These novel findings emphasize the higher order functions of this region, contributing to cognitive flexibility and planning of goal directed behavior. The investigation also reports for the first time somewhat contrasting neuromodulatory deficits produced by infusions of dopamine (DA) D2 and 5-HT2A receptor (R) antagonists into the same region, of possible significance for understanding cognitive deficits produced by anti-psychotic drugs.