Background: Recent evidence indicates that the gut-brain axis plays a role in mental well-being, with microbiota as a crucial component. Yet, it is still unclear how it influences cognitive...Show moreBackground: Recent evidence indicates that the gut-brain axis plays a role in mental well-being, with microbiota as a crucial component. Yet, it is still unclear how it influences cognitive reactivity, known as a predictor of depression. Understanding how the microbiota-gut-brain axis affects cognitive reactivity may contribute to enhancing interventions targeting cognitive reactivity and eventually depression. Objective: The current observational study investigated the association between cognitive reactivity and Alpha diversity in the gut microbiota, and the moderating role of enterotype among (self-reported) healthy Dutch adults (N = 75, M age = 24.04, SD = 3.43). Methods: The gut microbial composition and enterotype were based on a 16S rRNA analysis, after which the Shannon index was calculated to indicate Alpha diversity. Based on literature, enterotype was categorized into three groups: Bacteroides, Prevotella, and Ruminococcus. The LEIDS-r was used to measure cognitive reactivity. A simple linear regression and moderation analysis using Hayes PROCESS were performed. Results: The moderation analysis revealed a significant moderation effect; however, the overall model was not significant therefore the results should be interpreted carefully. The results demonstrated an association between gut microbiome diversity (Shannon index) and cognitive reactivity among participants in the Bacteroides dominant group and the Ruminococcus dominant group, whereas no such correlation was found among participants in the Prevotella dominant group. Discussion: The current findings suggest an enterotype-dependent link between gut microbiota diversity and cognitive reactivity in healthy adults, which may provide a new perspective for the development and deployment of therapeutic gut microbial interventions targeting cognitive reactivity and ultimately depressionShow less
Background: Suicidal ideation is a grave symptom of major depressive disorder (MDD), that can have long-lasting cognitive effects. Cognitive Reactivity (CR) is the reactivation of depressogenic...Show moreBackground: Suicidal ideation is a grave symptom of major depressive disorder (MDD), that can have long-lasting cognitive effects. Cognitive Reactivity (CR) is the reactivation of depressogenic cognitions by dysphoric mood states, after recovery. CR is important as it predicts relapse. Previous studies found that individuals who have contemplated suicide may be particularly vulnerable to reactivation of depressive cognitions; however, suicidal ideation was assessed retrospectively. The present study is prospective. Methods: Cohort study. Participants who met the DSM-IV diagnostic criteria for MDD were included if they no longer satisfied the criteria two years later (N = 943). CR scores during remission were compared between individuals who were not suicidal during their index (baseline) episode (SI-) (N = 346), versus those who were (SI+) (N = 597) — within which, a subcategory of those who attempted suicide in their lifetime (N = 152) was included. Results: During remission, SI+ participants had significantly higher hopelessness reactivity scores than SI- participants, even when factoring current depressive symptoms and suicidality, and anxiety comorbidity. Current hopelessness reactivity was significantly predicted by previous suicidal ideation, and to a lesser degree, feelings of worthlessness/guilt. Participants who had attempted suicide had significantly higher aggression reactivity, compared to without a history of suicidality. Limitations: Cognitive reactivity may have been influenced by the unaccounted disparity in participants’ most recent suicide attempt, and the number of previous depressive episodes. Conclusions: The results support the differential activation model of suicidality. Robust and strong longitudinal associations are drawn between suicidal ideation during depression, and a subsequent, distinct cognitive reactivity profile on the hopelessness dimension during remission. Given the profile specificity of cognitive reactivity, preventative measures for relapse are promising. Further research including the number of previous depressive episodes, suicide attempts and their recency may strengthen the validity of findings.Show less
