Jelena Brezo

Personality traits as correlates of suicidal ideation, suicide attempts, and suicide completions: a systematic review

Objective:  Involvement of personality traits in susceptibility to suicidality has been the subject of research since the 1950s. Because of the diversity of conceptual and methodological approaches, the extent of their independent contribution has been difficult to establish. Here, we review conceptual background and empirical evidence investigating roles of traits in suicidal behaviors.

Predicting suicide attempts in young adults with histories of childhood abuse

BACKGROUND Although childhood abuse is an important correlate of suicidality, not all individuals who were abused as children attempt suicide. AIMS To identify correlates and moderators of suicide attempts in adults reporting childhood physical abuse, contact sexual abuse, or both. METHOD A French-Canadian, school-based cohort (n=1684) was prospectively followed. RESULTS The identity of the abuser moderated the relationship of abuse frequency and suicide attempts, with individuals abused by their immediate family being at highest risk. Although paternal education exhibited negative associations (OR=0.71, 95% CI 0.58-0.88), several externalising phenotypes had positive associations with suicide attempts: disruptive disorders (OR=3.10, 95% CI 1.05-9.15), conduct problems (OR=1.09, 95% CI 1.01-1.19) and childhood aggression (OR=1.41, 95% CI 1.08-1.83). CONCLUSIONS Characteristics of the abuser and abusive acts may be important additional indicators of risk for suicide attempts. Future research needs to employ developmental approaches to examine the extent and mechanisms by which childhood abuse contributes to the shared variance of suicidality, maladaptive traits and psychopathology.

The genetics of suicide: a critical review of molecular studies

Genetic epidemiology research has shown that genes contribute to suicide risk. Unfortunately, the first 30 years of candidate-based association studies have provided little information about the specific genetic contributors. This article reviews genetic association studies of suicidal phenotypes published to date. Possible theoretical, methodological, and operational challenges accounting for the modest success of association studies in the field are also discussed. The authors conclude that future research may benefit from using a more systematic and comprehensive selection of candidate genes and variants, examining gene-environment and gene-gene interactions, and investigating higher-order moderators.

Natural history of suicidal behaviors in a population-based sample of young adults.

BACKGROUND Suicidal behaviors in young individuals represent an important public health problem. Understanding their natural history and relationships would therefore be of clinical and research value. In this study, we examined the natural histories of several suicidal behaviors and investigated two conceptual models of suicidality (dimensional and categorical) in the context of adolescent and adult-onset suicide attempts. METHOD Participants were members of a prospectively studied, representative, population-based school cohort followed since age 6 (n = 3017) through mid-adolescence (n = 1715) to their early twenties (n = 1684). Outcome measures included suicidal ideation, attempts and completions. RESULTS Approximately one in 500 individuals died by suicide. About 33% had suicidal ideas and 9.3% made at least one suicide attempt. Over half (4.9%) of the self-reported attempters made their first attempt before age 18. With the exception of current suicidal ideas, non-fatal suicidal behaviors were more prevalent in females. In general, parental and cross-sectional self-reports underestimated suicidality rates. Aikaike (AIC) and Bayesian (BIC) information criteria suggested the ordinal model, and dimensional conceptualization of suicide attempts of different onset age, to be more optimal than its multinomial/categorical counterpart (ordinal: AIC 567.55, BIC 635.67; multinomial: AIC 616.59, BIC 723.83). Both models, nevertheless, identified five common factors of relevance to suicidal diathesis: gender, disruptive disorders, childhood anxiousness and abuse, and suicidal thoughts. CONCLUSIONS Non-fatal suicidal behaviors in adolescents and young adults are more common than suggested by cross-sectional studies and parental reports. The dimensional model may be more useful in explaining the relationship of suicide attempts of different age of onset.

Identifying correlates of suicide attempts in suicidal ideators: a population-based study

BACKGROUND Identification of factors that distinguish between ideators who act on their suicidal thoughts from those who do not is an important clinical and research objective. METHOD We examined correlates of suicide attempts in suicidal ideators, members of a French-Canadian, school-based cohort. Suicidal thoughts were evaluated in adolescence and early adulthood in the total sample of suicidal ideators, who were then stratified into subgroups consisting of persistent ideators, male ideators and female ideators. RESULTS In addition to persistent suicidal ideas [odds ratios (ORs) 2.1-2.8], Axis I psychopathology, female gender and childhood sexual abuse (CSA) were the most consistent correlates of suicide attempts. Externalizing disorders were significant contributors in persistent ideators [drug misuse: OR 2.8, 95% confidence interval (CI) 1.1-6.9] and in male ideators in particular (disruptive disorders: OR 5.9, 95% CI 2.2-16.0). In women, psychiatric co-morbidity also had a significant effect (OR 1.6, 95% CI 1.1-2.1). CSA was of relevance in both women (OR 1.2, 95% CI 1.1-1.4) and persistent ideators (OR 1.3, 95% CI 1.1-1.5). Personality traits showed gender-specific contribution with affective instability (OR 1.1, 95% CI 1.01-1.1) and anxiousness (OR 1.3, 95% CI 1.1-1.7) contributing in men and disruptive aggression (OR 1.1, 95% CI 1.03-1.3) in women. CONCLUSIONS Correlates of suicide attempts in suicidal ideators vary as a function of the persistence of suicidal ideas and gender. This heterogeneity across subgroups of suicidal ideators may be attributed, at least in part, to differences between the sexes, early environmental adversity, maladaptive personality, and psychiatric symptoms. Further exploration and continued prospective follow-up is necessary to examine these possibilities.

Differences and similarities in the serotonergic diathesis for suicide attempts and mood disorders: a 22-year longitudinal gene–environment study

To investigate similarities and differences in the serotonergic diathesis for mood disorders and suicide attempts, we conducted a study in a cohort followed longitudinally for 22 years. A total of 1255 members of this cohort, which is representative of the French-speaking population of Quebec, were investigated. Main outcome measures included (1) mood disorders (bipolar disorder and major depression) and suicide attempts by early adulthood; (2) odds ratios and probabilities associated with 143 single nucleotide polymorphisms in 11 serotonergic genes, acting directly or as moderators in gene–environment interactions with childhood sexual or childhood physical abuse (CPA), and in gene–gene interactions; (3) regression coefficients for putative endophenotypes for mood disorders (childhood anxiousness) and suicide attempts (childhood disruptiveness). Five genes showed significant adjusted effects (HTR2A, TPH1, HTR5A, SLC6A4 and HTR1A). Of these, HTR2A variation influenced both suicide attempts and mood disorders, although through different mechanisms. In suicide attempts, HTR2A variants (rs6561333, rs7997012 and rs1885884) were involved through interactions with histories of sexual and physical abuse whereas in mood disorders through one main effect (rs9316235). In terms of phenotype-specific contributions, TPH1 variation (rs10488683) was relevant only in the diathesis for suicide attempts. Three genes contributed exclusively to mood disorders, one through a main effect (HTR5A (rs1657268)) and two through gene–environment interactions with CPA (HTR1A (rs878567) and SLC6A4 (rs3794808)). Childhood anxiousness did not mediate the effects of HTR2A and HTR5A on mood disorders, nor did childhood disruptiveness mediate the effects of TPH1 on suicide attempts. Of the serotonergic genes implicated in mood disorders and suicidal behaviors, four exhibited phenotype-specific effects, suggesting that despite their high concordance and common genetic determinants, suicide attempts and mood disorders may also have partially independent etiological pathways. To identify where these pathways diverge, we need to understand the differential, phenotype-specific gene–environment interactions such as the ones observed in the present study, using suitably powered samples.

Personality traits as correlates of suicide attempts and suicidal ideation in young adults

BACKGROUND Adults in their twenties appear to be at high risk for suicidal behaviors (SBs) and there is substantial evidence suggesting that certain personality traits may increase individual vulnerability to suicide. METHOD We investigated relationships of personality traits with two SBs in a cohort (n=1140) of 21- to 24-year-old adults, representative of the general population of Quebec. Subjects were assessed using a series of structured diagnostic and personality trait questionnaires. Multivariate logistic regression analyses were employed to identify personality trait correlates of suicide-attempt history and serious suicidal ideation in the context of other known risk factors, such as psychopathology and experiences of childhood sexual and physical abuse. RESULTS Traits of conduct problems contributed to both suicide attempts [odds ratio (OR) 1.03, 95% confidence interval (CI) 1.01-1.06] and suicidal ideation (OR 1.04, 95% CI 1.02-1.07), while identity problems (OR 1.10, 95% CI 1.07-1.13) and gender-moderated impulsivity contributed exclusively to suicidal ideation. CONCLUSIONS Personality traits may make independent contributions to current suicidal ideation and previous suicide attempts in certain subgroups of suicidal individuals. In order to further explore their utility as markers of suicide risk and targets of intervention further investigation in clinical samples and other cultural and age groups is necessary.

Childhood Trajectories of Anxiousness and Disruptiveness as Predictors of Suicide Attempts

OBJECTIVE To investigate the association of childhood trajectories of anxiousness and disruptiveness with suicide attempts in early adulthood. DESIGN Prospective cohort study. SETTING Public francophone schools in Quebec, Canada, from the 1986 to 1988 school years. PARTICIPANTS Of 4,488 French Canadian children attending kindergarten, a representative group of 1,001 boys and 999 girls was chosen for follow-up. Of these, 1,144 individuals participated in the study during early adulthood. MAIN OUTCOME MEASURES Suicide attempt histories by early adulthood, adjusted odds ratios (ORs) associated with membership in high- vs low-risk trajectories of anxiousness and disruptiveness, moderation (by sex), and mediation (by adolescent Axis I disorders). RESULTS We observed 4 distinct developmental profiles of anxiousness and disruptiveness and a frequent co-occurrence of similar levels of these traits. In contrast to anxiousness trajectories (OR = 1.60; 95% confidence interval, 1.00-2.65), disruptiveness (OR = 1.80; 95% confidence interval, 1.03-3.13) and joint (OR = 1.88; 95% confidence interval, 1.05-3.37) trajectories made statistically significant contributions to suicide attempts. We found no support for mediation by adolescent anxiety/mood or disruptive disorders. Sex, however, moderated the effect of joint trajectories, increasing the risk of suicide attempts in women (OR = 3.60; Wald chi(2) = 10.93; P < .001) but not men (OR = 0.80; Wald chi(2) = 0.23; P = .64) displaying both anxious and disruptive traits as children. CONCLUSIONS Anxious-disruptive girls and disruptive boys appear to be more likely than their peers to attempt suicide by early adulthood. Preventive efforts will require more research into the possible mechanisms behind this early sex difference, ie, gene-environment interplays and nonpsychiatric mediators.

Broad and narrow personality traits as markers of one-time and repeated suicide attempts: a population-based study

BackgroundStudying personality traits with the potential to differentiate between individuals engaging in suicide attempts of different degrees of severity could help us to understand the processes underlying the link of personality and nonfatal suicidal behaviours and to identify at-risk groups. One approach may be to examine whether narrow, i.e., lower-order personality traits may be more useful than their underlying, broad personality trait dimensions.MethodsWe investigated qualitative and quantitative differences in broad and narrow personality traits between one-time and repeated suicide attempters in a longitudinal, population-based sample of young French Canadian adults using two multivariate regression models.ResultsOne broad (Compulsivity: OR = 2.0; 95% CI 1.2–3.5) and one narrow personality trait (anxiousness: OR = 1.1; 95% CI 1.01–1.1) differentiated between individuals with histories of repeated and one-time suicide attempts. Affective instability [(OR = 1.1; 95% CI 1.04–1.1)] and anxiousness [(OR = .92; 95% CI .88–.95)], on the other hand, differentiated between nonattempters and one-time suicide attempters.ConclusionEmotional and cognitive dysregulation and associated behavioural manifestations may be associated with suicide attempts of different severity. While findings associated with narrow traits may be easier to interpret and link to existing sociobiological theories, larger effect sizes associated with broad traits such as Compulsivity may be better suited to objectives with a more clinical focus.

A Deletion in Tropomyosin-Related Kinase B and the Development of Human Anxiety

BACKGROUND The tropomyosin-related kinase B (TrkB)/brain-derived neurotrophic factor system has been associated with psychiatric disorders, and animal models of defects in this system suggest that it might have a particular role in anxiety. METHODS DNA sequencing and cloning were used to identify a mutation in TrkB, and four different cell lines were used to assess functionality. Clinical samples were from a 22-year longitudinal cohort representative of the Quebec general population (n = 640 subjects), randomly selected when they were in kindergarten. Anxiety-related traits were measured with the Social Behaviour Questionnaire, the Diagnostic Assessment of Personality Pathology-Brief Questionnaire, and the Diagnostic Interview Schedule for DSM-IIIR. RESULTS An 11 base pair deletion in TrkB is significantly associated with increases in anxiety traits during childhood and the development of anxiety disorders in adulthood. We found that this deletion impaired transcription in some human cell lines. CONCLUSIONS The identification of this deletion provides additional support for the role of TrkB in modulating anxiety-related traits in human.