Distinct effects of over-general autobiographical memory on suicidal ideation among depressed and healthy people

Lifetime Suicide Attempts in Otherwise Psychiatrically Healthy Individuals

Importance

Not all people who die by suicide have a psychiatric diagnosis; yet, little is known about the percentage and demographics of individuals with lifetime suicide attempts who are apparently psychiatrically healthy. If such suicide attempts are common, there are implications for suicide risk screening, research, policy, and nosology.

Objective

To estimate the percentage of people with lifetime suicide attempts whose first attempt occurred prior to onset of any psychiatric disorder.

Design, Setting, and Participants

This cross-sectional study used data from the US National Epidemiologic Study of Addictions and Related Conditions III (NESARC-III), a cross-sectional face-to-face survey conducted with a nationally representative sample of the US civilian noninstitutionalized population, and included persons with lifetime suicide attempts who were aged 20 to 65 years at survey administration (April 2012 to June 2013). Data from the NESARC, Wave 2 survey from August 2004 to September 2005 were used for replication. Analyses were performed from April to August 2023.

Exposure

Lifetime suicide attempts.

Main Outcomes and Measures

The main outcome was presence or absence of a psychiatric disorder before the first lifetime suicide attempt. Among persons with lifetime suicide attempts, the percentage and 95% CI of those whose first suicide attempt occurred before the onset of any apparent psychiatric disorders was calculated, weighted by NESARC sampling and nonresponse weights. Separate analyses were performed for males, females, and 3 age groups (20 to <35, 35-50, and >50 to 65 years).

Results

In the total sample of 36 309 respondents, 1948 persons had lifetime suicide attempts; 66.8% (95% CI, 64.1%-69.4%) were female, and 6.2% (95% CI, 4.9%-7.4%) had no apparent lifetime psychiatric diagnoses when surveyed. In addition, 13.4% (95% CI, 11.6%-15.2%) made their first suicide attempt prior to psychiatric disorder onset. Thus, an estimated 19.6% of respondents first attempted suicide without an antecedent psychiatric disorder. No significant age or sex differences were detected in the percentage of those with lifetime suicide attempts absent psychiatric disorders, although females were more likely than males to attempt suicide in the year of psychiatric disorder onset (14.9% [95% CI, 12.5%-17.3%] vs 8.6% [95% CI, 6.0%-11.2%]; P < .001), and attempts were less frequent among those older than 50 to 65 years (3.9% [95% CI, 3.5%-4.4%] vs 6.1% [95% CI, 5.4%-6.8%] for 35-50 years and 6.2% [95% CI, 5.6%-6.9%] for 20 to <35 years; P < .001).

Conclusions and Relevance

In this study, an estimated 19.6% of individuals who attempted suicide did so despite not meeting criteria for an antecedent psychiatric disorder. This finding challenges clinical notions of who is at risk for suicidal behavior and raises questions about the safety of limiting suicide risk screening to psychiatric populations.

Occurrence and characteristics of suicidal ideation in psychiatrically healthy individuals based on ecological momentary assessment

Decedents with no known mental disorder comprise 5-40% of suicides, suggesting that suicide ideation (SI) and behavior may occur in the psychiatrically healthy with important implications for suicide risk screening. Healthy Volunteers (HV) and patients with Major Depressive Disorder (MDD) provided 7 days of Ecological Momentary Assessment (EMA) data about SI and stressors. Longitudinal mixed effects logistic regression models compared HV and patient SI and stressors. Mixed effects linear regression models compared HVs' and patients' SI score change from the previous epoch's SI score when each stressor occurred. HVs (n = 42) reported less frequent (p < 0.001) and less intense SI (p < 0.003) than patients (n = 80), yet did endorse SI and/or SI-related items in 44% of EMA epochs, endorsing SI items in 25% of epochs with non-zero SI scores. For 7 of 8 stressors, patients reported stressors more often than HVs (all p < 0.001) responding to them with increased SI (0.0001 < p < 0.0472). HVs were relatively resilient to stressors, reporting SI increases only in response to neglect (p < 0.0147). Although SI and SAs are documented among psychiatrically healthy individuals, scientific attention to these observations has been scant. Real-time SI measurement showed that HVs' SI was less pronounced than MDD patients', but was endorsed, nonetheless. Patients were more likely to report stressors than HVs, perhaps due to greater sensitivity to the environment, and reported SI in response to stressors, which was less common in HVs. Both MDD patients and HVs most often manifested passive SI (viz, "decreased wish to live"). However, passive SI (viz, "desire for death"), may predict suicide, even absent SI per se (thinking about killing yourself). This study validates the utility of real-time SI assessment, showing that HVs endorse SI items in 11% of epochs, which implies that suicide risk screening focused on those with mental disorders may be too narrow an approach.

EEG microstate analysis reveals large-scale brain network alterations in depressed adolescents with suicidal ideation

BACKGROUND

Accumulating evidence showed abnormalities in brain network connectivity in depressive individuals with suicidal ideation (SI). We aimed to investigate the large-scale brain network dynamics in adolescents with SI and major depressive disorder (MDD).

METHODS

We recruited 47 first-episode drug-naïve adolescents with MDD and SI, 26 depressed adolescents without SI (noSI), and 26 age-matched healthy controls (HC). The Columbia Suicidal Ideation Severity Scale (C-SSRS) was utilized to assess suicide ideation. We acquired 64-channel resting-state EEG recordings from all subjects and used microstate analysis to investigate the large-scale brain network dynamics.

RESULTS

We observed a significant reduction in the occurrence and coverage of microstate B within the SI group when contrasted with the noSI group. Conversely, there was a significant increase in the occurrence and coverage of microstate A in the SI group as compared to the HC group. Additionally, we observed heightened transition probabilities from microstates D and C to microstate A in the SI group; meanwhile, transitions from microstate D to B were more prevalent in the noSI group. Furthermore, the noSI group exhibited a significant decline in the transition probabilities from microstate D to microstate C.

LIMITATIONS

The cross-sectional nature limits the capacity to determine whether microstate dynamics have prognostic significance for SI.

CONCLUSION

We provided evidence that depressed adolescents with SI have a distinct pattern in microstate dynamics compared to those without SI. These findings suggest that microstate dynamics might serve as a potential neurobiomarker for identifying SI in depressed adolescents.

The relationship between childhood interpersonal and non-interpersonal trauma and autobiographical memory: a systematic review

Childhood trauma can have negative effects on several domains of mental functioning, including Autobiographical Memory (AM). Conflicting results emerge in the scientific literature regarding the effects of childhood trauma on AM. In this review, we explored the relationship between the childhood trauma and AM, classifying childhood trauma as interpersonal, non-interpersonal and overall (interpersonal and non-interpersonal). We carried out a systematic literature review, following the guidelines of the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA statement). From searching the PubMed, Scopus, and Web of Science databases, we identified 48 studies conducted from 2014 to 2023, which were included when they: (a) were written in English, (b) investigated the relationship between AM and childhood trauma, (c) included a sample of children, adolescents, or adults who had experienced childhood interpersonal and/or non-interpersonal trauma. Of the 48 eligible studies, 29 referred to trauma of an interpersonal nature, 12 to trauma of a non-interpersonal nature, and 7 to overall trauma. Regarding the relationship between childhood trauma and AM, 24 studies found a negative relationship between childhood interpersonal trauma and AM; among the articles on non-interpersonal trauma, 10 studies found no relevant relationship; in the studies on overall trauma, 4 articles found negative relationship between overall trauma and AM. The literature explored in our systematic review supports the prevalence of a negative relationship between interpersonal childhood trauma and AM. This relationship is present regardless of psychiatric disorders (e.g., Depression, Post Traumatic Stress Disorder, and Personality Disorders), and in the presence of the latter, AM results even more fragmented. Future research should use more accurate methodologies in identifying and classifying childhood trauma in order to more precisely determine its effect on AM.

Cognitive-Emotional Benefits of Weekly Exposure to Nature: A Taiwanese Study on Young Adults

Empirical evidence of nature’s benefits to cognitive and emotional well-being is emerging. In this study, 48 Taiwanese young adults (24 indoors and 24 outdoors in urban greenspace) completed four weekly 45 min exposure sessions. The study explores whether the outdoor group surpasses the indoor group in cognitive and emotional well-being and nature connectedness. There were no significant differences for the indoor group across different measurements of rumination and connectedness to nature. However, the outdoor group displayed a significant reduction in rumination post-test compared to the one week prior and the first session. Similarly, for sessions two, three, and four and one month post-test, the outdoor group’s connectedness to nature was significantly higher than pre-test. Specific autobiographical memory was enhanced while overgeneral autobiographic memory was reduced during the third and fourth sessions, though these changes were not sustained at one-month follow-up. Surprisingly, both groups yielded similar results in decreased depression, anxiety, and stress. A significantly higher number of outdoor group participants had employed nature exposure for coping with stress or emotions after the program. We discuss the implications of this for counseling services for young adults and highlight future research possibilities, including formulating a nature-exposure protocol and a program evaluation for consolidating evidence-based nature prescription.