The relationship of impulsivity and cortical thickness in depressed and non-depressed adolescents

Symptoms characteristics of personality disorders associated with suicidal ideation and behaviors in a clinical sample of adolescents with a depressive disorder

Introduction

Pathological personality traits have repeatedly been identified as important risk factors for suicidal ideation and behaviors. Moreover, impulsive-aggressive traits, have shown a consistent association with suicidal behaviors across the lifespan. Adolescence represents a critical period for the emergence of different personality traits, mood disorders, and suicidal behaviors, but the relationship between these variables remain poorly understood.

Methods

These variables were examined in a cross-sectional case-control design involving three groups: 30 adolescents with a depressive disorder and past suicide attempt (Mean Age = 16.2, Females = 26), 38 adolescents with a depressive disorder but without past suicide attempt (Mean age = 16.0, Females = 29), and 34 healthy adolescent controls (Mean age = 15.2, Females = 22). Suicidal ideations were indexed using Suicidal Behavior Questionnaire (SBQ-R), psychiatric disorder assessed using a semi-structured questionnaire (K-SADS-PL), depressive symptoms with the Beck Depressive Inventory (BDI), symptoms characteristics of personality disorders with the Scheduled Clinical Interview for the DSM-IV (SCID-II) screening questionnaire, and impulsivity with the Barratt Impulsivesness Scale (BIS).

Results

Findings showed that impulsivity (F = 11.0, p < 0.0001) and antisocial symptoms characteristics of personality disorders (p < 0.001, d = 0.70) displayed the most robust association with adolescent suicide attempts. Borderline symptoms characteristics of personality disorders did not discriminate attempters from non-attempters but presented high correlations with suicidal ideation and depression severity. In an item-wise analysis, suicide attempt status was uniquely correlated with symptoms characteristics of an antisocial personality disorder. Suicide attempt status also correlated with non-suicidal self-injury and a chronic feeling of emptiness.

Discussion

The caveats of this cross-sectional study include the stability of symptoms characteristics of personality disorders in adolescence and the limited sample size. In sum, suicidal behaviors were characteristically correlated with increased impulsivity and antisocial symptoms characteristics of personality disorders, but other symptoms characteristics of personality disorders were relevant to adolescent depression and suicidal ideation. Understanding the emergence of symptoms characteristics of personality disorders and suicidal behaviors in a developmental context can ultimately inform not only the neurobiological origin of suicidal behaviors, but also provide new avenues for early detection and intervention.

A Systematic Review of MRI Studies and the "Emotional paiN and social Disconnect (END)" Brain Model of Suicidal Behavior in Youth

Introduction

Risk of suicidal ideation and suicidal behaviors greatly increases during adolescence, and rates have risen dramatically over the past two decades. However, few risk factors or biomarkers predictive of suicidal ideation or attempted suicide have been identified in adolescents. Neuroimaging correlates hold potential for early identification of adolescents at increased risk of suicidality and risk stratification for those at high risk of suicide attempt.

Methods

In this systematic review, we evaluated neural regions and networks associated with suicidal ideation and suicide attempt in adolescents derived from magnetic resonance imaging (MRI) studies. A total of 28 articles were included in this review.

Results

After descriptively synthesizing the literature, we propose the Emotional paiN and social Disconnect (END) model of adolescent suicidality and present two key neural circuits: (1) the emotional/mental pain circuit and (2) the social disconnect/distortion circuit. In the END model, the emotional pain circuit-consisting of the cerebellum, amygdala, and hippocampus-shows similar aberrations in adolescents with suicidal ideation as in those with a history of a suicide attempt (but to a smaller degree). The social disconnect circuit is unique to adolescent suicide attempters and includes the lateral orbitofrontal cortex (OFC), the temporal gyri, and the connections between them.

Conclusion

Our proposed END brain model of suicidal behavior in youth, if confirmed by future prospective studies, can have implications for clinical goals of early detection, risk stratification, and intervention development. Treatments that target emotional pain and social disconnect may be ideal interventions for reducing suicidality in adolescents.

History of suicide attempts associated with the thinning right superior temporal gyrus among individuals with schizophrenia

Individuals with schizophrenia have higher rates of suicide attempts than the general population. Specific cortical abnormalities (e.g., the cortical surface area and thickness) may be associated with a history of suicide attempts. We recruited 74 individuals with schizophrenia (37 suicide attempters were individually matched with 37 non-attempters on age, sex, phase of illness, and study center) and 37 healthy volunteers. The cortical surface area and thickness data were extracted from structural MRI and compared between the groups. Suicide attempters showed significantly smaller surface areas in the whole brain (p = .028, Cohen's d = -0.54) than non-attempters. No association was found between the cortical surface area of individual brain regions and a history of suicide attempts. The mean cortical thickness did not differ significantly between the groups; however, suicide attempters demonstrated a thinner cortex in the right superior temporal gyrus (p < .001, q = 0.037, Cohen's d = -0.88). These findings indicate that a history of suicide attempts among individuals with schizophrenia is associated with a reduction in the global cortical surface area and specific cortical thinning of the right superior temporal gyrus. The morphometric alteration of the right superior temporal gyrus may represent a biomarker of suicidal behavior in individuals with schizophrenia.

Diminished frontal pole size and functional connectivity in young adults with high suicidality

BACKGROUND

Suicide rates among young people have been increasing in recent years, yet no validated methods are available for identifying those who are at greatest risk for suicide. Abnormalities in the medial prefrontal cortex have been previously observed in suicidal individuals, but confounding factors such as treatment and chronic illness may have contributed to these findings. Thus, in this study we tested whether the size of the medial prefrontal cortex is altered in suicidal young adults who have received no treatment with psychotropic medications.

METHODS

Suicidality was evaluated using the Suicide Behaviors Questionnaire-Revised (SBQ-R) and surface areas of four regions-of-interest (ROIs) within the medial prefrontal cortex were measured using magnetic resonance imaging (MRI) in a cohort of college students (n = 102). In addition, a secondary seed-based functional connectivity analysis was conducted using resting-state functional MRI data. Areas and functional connectivity of the medial prefrontal cortex of young adults with high suicidality (HS; SBQ-R score > 7; n = 20) were compared to those with low suicidality (LS; SBQ-R score = 3, n = 37).

RESULTS

Compared to the LS group, the HS group had a significantly lower surface area of the right frontal pole (p < 0.05, Bonferroni-corrected) and significantly lower functional connectivity of the right frontal pole with the bilateral inferior frontal cortex (p < 0.001, Monte-Carlo corrected).

LIMITATION

These findings require replication in a larger sample and extension in younger (adolescent) populations.

CONCLUSION

Diminished frontal pole surface area and functional connectivity may be linked to elevated levels of suicidality in young people.

Functional activation of insula and dorsal anterior cingulate for conflict control against larger monetary loss in young adults with subthreshold depression: a preliminary study

Subthreshold depression (StD) is associated with higher risk of later developing major depressive disorder (MDD). Deficits of goal-directed behaviors regarding the motional, motivational, and conflict control are found in MDD. The current study examined neural underpinning of conflict control against monetary punishment in StD compared to MDD and healthy controls (HC). Seventy-one participants (HC, n = 27; StD, n = 21; MDD, n = 23) in their mid-20's completed self-reports. Preprocessing of functional magnetic resonance imaging acquired for the Simon task against larger or smaller monetary punishment was conducted using ENIGMA HALFpipe version 1.2.1. Neural correlates of conflict control against monetary punishment that could vary with either diagnosis or PHQ-9 total score were examined using a general linear model of FSL. Simon effect was effective for reaction time and accuracy in every subgroup of diagnosis and regardless of the size of monetary punishment. Conflict control against larger monetary loss was associated with higher functional activation of left insula in StD than HC and MDD. StD showed lower functional activation of left dorsal anterior cingulate (dACC) than MDD for conflict control against larger monetary loss. For conflict control against smaller monetary loss, StD demonstrated higher functional activation of left paracentral lobule and right putamen compared to HC. Directed acyclic graphs showed directional associations from suicidal ideation, sadness, and concentration difficulty to functional activation of paracentral lobule, ventromedial prefrontal cortex (vmPFC), and thalamus for conflict control against monetary loss. Differential functional activation of insula and dACC for conflict control against larger monetary loss could be a brain phenotype of StD. Item-level depressive symptoms of suicidal ideation, sadness, and concentration difficulty could be reflected in the conflict control-related functional activation of paracentral lobule (against smaller monetary loss), vmPFC and thalamus (against larger monetary loss), respectively.

Altered Resting-State Networks in Adolescent Non-Suicidal Self-Injury - A Graph Theory Analysis

Non-suicidal self-injury (NSSI) is a highly prevalent transdiagnostic symptom and risk marker for mental health problems among adolescents. Research on the neurobiological mechanisms underlying NSSI is needed to clarify the neural correlates associated with the behavior. We examined resting-state functional connectivity in n = 33 female adolescents aged 12–17 years engaging in NSSI, and in n = 29 age-matched healthy controls using graph theory. Mixed linear models were evaluated with the Bayes Factor to determine group differences on global and regional network measures and associations between network measures and clinical characteristics in patients. Adolescents engaging in NSSI demonstrated longer average characteristic path lengths and a smaller number of weighted hubs globally. Regional measures indicated lower efficiency and worse integration in (orbito)frontal regions and higher weighted coreness in the pericalcarine gyrus. In patients, higher orbitofrontal weighted local efficiency was associated with NSSI during the past month while lower pericalcarine nodal efficiency was associated with suicidal thoughts in the past year. Higher right but lower left pericalcarine weighted hubness was associated with more suicide attempts during the past year. Using a graph-based technique to identify functional connectivity networks, this study adds to the growing understanding of the neurobiology of NSSI.

Association of Prefrontal Cortex Thinning with High Impulsivity in Healthy Adults

OBJECTIVE

Studies have been conducted to identify brain structural alterations related to high impulsivity in psychiatric populations. However, research on healthy subjects is relatively less extensive. Therefore, we aimed to investigate the correlation between the cortical thickness of whole brain regions and the impulsivity level in a healthy population.

METHODS

We included 100 healthy participants aged 19-65 years. Their T1-weighted magnetic resonance images and the 23-item Barratt Impulsiveness Scale (BIS) score were obtained. The patients were divided into high and low impulsivity groups according to the 75th percentile score of the BIS in the sample. The thickness of each cortical region was calculated using the FreeSurfer, and the difference in cortical thickness of the whole brain between the high and low impulsivity groups was analyzed using one-way analysis of covariance including age, sex, education level, and total intracranial cavity volume as covariates.

RESULTS

The high impulsivity group showed significant cortical thinning in the left pars opercularis. The cortical thickness of the left pars opercularis significantly correlated negatively with the total, attention, and motor scores of the BIS scale.

CONCLUSION

Our findings suggest that prefrontal cortex thinning may play an important role in the development of high impulsivity in healthy adults.

The Association Between Insular Subdivisions Functional Connectivity and Suicide Attempt in Adolescents and Young Adults with Major Depressive Disorder

Previous studies demonstrated the possible involvement of insula in suicide owing to depression. However, the function of insula in young depressed patients with suicide attempt (SA) remains to be revealed. This study aimed to explore the association between resting-state functional connectivity (FC) of insula and SA in young depressed patients. Fifty-eight adolescents and young adults with major depressive disorder, including 22 with a history of at least one SA (SA group) and 36 without a history of SA (NSA group) were scanned with a 3.0T functional magnetic resonance imaging system, and the resting-state functional magnetic resonance imaging data was extracted. Whole brain resting-state FC of insular subdivisions were compared between the two groups. Significantly increased FC of the left posterior insula with the orbital part of left inferior frontal gyrus, the right supplementary motor area and the bilateral paracentral lobule extending to the bilateral middle cingulate cortex was observed in the SA group compared with the NSA group. In addition, the orbital part of left superior frontal gyrus in the SA group exhibited significantly increased FC with the right posterior insula compared with the NSA group. However, no significant correlation was found between the insular subdivisions FC and different clinical variables in two groups. The present study highlighted the disruptions of the resting-state FC of the posterior insula with the orbitofrontal cortex and a series of motor cortices, and added incremental value to the knowledge of the neural mechanism underlying SA in young depressed patients.

Neural Correlates Associated With Suicide and Nonsuicidal Self-injury in Youth

There is no definitive neural marker of suicidal thoughts and behaviors (STBs) or nonsuicidal self-injury (NSSI), and relative to adults, research in youth is more limited. This comprehensive review focuses on magnetic resonance imaging studies reporting structural and functional neural correlates of STBs and NSSI in youth to 1) elucidate shared and independent neural alternations, 2) clarify how developmental processes may interact with neural alterations to confer risk, and 3) provide recommendations based on convergence across studies. Forty-seven articles were reviewed (STBs = 27; NSSI = 20), and notably, 63% of STB articles and 45% of NSSI articles were published in the previous 3 years. Structural magnetic resonance imaging research suggests reduced volume in the ventral prefrontal and orbitofrontal cortices among youth reporting STBs, and there is reduced anterior cingulate cortex volume related to STBs and NSSI. With regard to functional alterations, blunted striatal activation may characterize STB and NSSI youth, and there is reduced frontolimbic task-based connectivity in suicide ideators and attempters. Resting-state functional connectivity findings highlight reduced positive connectivity between the default mode network and salience network in attempters and show that self-injurers exhibit frontolimbic alterations. Together, suicidal and nonsuicidal behaviors are related to top-down and bottom-up neural alterations, which may compromise approach, avoidance, and regulatory systems. Future longitudinal research with larger and well-characterized samples, especially those integrating ambulatory stress assessments, will be well positioned to identify novel targets that may improve early identification and treatment for youth with STBs and NSSI.

Application of a diathesis-stress model to the interplay of cortical structural development and emerging depression in youth

Cross-sectional studies in adults have long identified differences in cortical structure in adults with depression compared to healthy adults, with most studies identifying reductions in grey matter volume, cortical thickness, and surface area in primarily frontal cortical regions including the OFC, ACC, and variable sub-regions of the PFC. However, when, why, and for whom these neural correlates of depression emerge remains poorly understood, necessitating developmental study of associations between depression and cortical structure. We systematically reviewed studies examining these associations in child/adolescent samples, and applied a developmentally-focused diathesis-stress model to understand the impacts of depressogenic risk-factors and stressors on the development of structural neural correlates of depression. Cross-sectional findings in youth are generally similar to those found in adults, but vary in magnitude and direction of effects. Preliminary evidence suggests that age, sex, severity, and comorbidity moderate these associations. Longitudinal studies show depression prospectively predicting cortical structure and structure predicting emerging depression. Consistent with a diathesis-stress model, associations have been noted between risk-factors for depression (e.g., genetic risk, family risk) and environmental stressors (e.g., early life stress) and structural neural correlates. Further investigation of these associations across development with attention to vulnerability factors and stressors is indicated.

Atypical Cortical Activation During Risky Decision Making in Disruptive Behavior Disordered Youths With Histories of Suicidal Ideation

BACKGROUND

Suicidality is a leading cause of death among adolescents. In addition to other psychiatric conditions, youths with attention-deficit/hyperactivity disorder (ADHD) and disruptive behavior disorders (DBDs) are at heightened risk for suicide. Decision-making deficits are a hallmark symptom of ADHD and DBDs and are also implicated in suicidal behavior. We examined behavioral and neural differences in decision making among youths with ADHD and DBDs with (SI+) and without (SI-) histories of suicidal ideation.

METHODS

The Balloon Analog Risk Task, a risky decision-making task, was completed by 57 youths with ADHD and DBDs (38% SI+) during functional magnetic resonance imaging. Mean stop wager (mean wager at which youths bank money) was the primary measure of risk taking. We conducted whole-brain and region-of-interest analyses in the anterior cingulate cortex and orbitofrontal cortex (OFC) during choice (win vs. inflate) and outcome (inflate vs. explode) contrasts using parametric modulators accounting for probability of balloon explosion.

RESULTS

There were no differences between SI+ and SI- youths in Balloon Analog Risk Task performance. SI+ youths showed decreasing activation in the right medial frontal gyrus when choosing inflate as explosion probability increased compared with SI- youths. During explosions, SI- youths showed increasing activation in the left OFC as explosions became more likely. SI+ showed increasing left medial OFC activity in response to inflations as explosion probability increased.

CONCLUSIONS

SI+ youths may show heightened sensitivity to immediate reward and decreased sensitivity to potential loss as evidenced by medial frontal gyrus activity. OFC findings suggest that SI+ youths may be drawn to reward even when there is high probability of loss.

Imaging suicidal thoughts and behaviors: a comprehensive review of 2 decades of neuroimaging studies

Identifying brain alterations that contribute to suicidal thoughts and behaviors (STBs) are important to develop more targeted and effective strategies to prevent suicide. In the last decade, and especially in the last 5 years, there has been exponential growth in the number of neuroimaging studies reporting structural and functional brain circuitry correlates of STBs. Within this narrative review, we conducted a comprehensive review of neuroimaging studies of STBs published to date and summarize the progress achieved on elucidating neurobiological substrates of STBs, with a focus on converging findings across studies. We review neuroimaging evidence across differing mental disorders for structural, functional, and molecular alterations in association with STBs, which converges particularly in regions of brain systems that subserve emotion and impulse regulation including the ventral prefrontal cortex (VPFC) and dorsal PFC (DPFC), insula and their mesial temporal, striatal and posterior connection sites, as well as in the connections between these brain areas. The reviewed literature suggests that impairments in medial and lateral VPFC regions and their connections may be important in the excessive negative and blunted positive internal states that can stimulate suicidal ideation, and that impairments in a DPFC and inferior frontal gyrus (IFG) system may be important in suicide attempt behaviors. A combination of VPFC and DPFC system disturbances may lead to very high risk circumstances in which suicidal ideation is converted to lethal actions via decreased top-down inhibition of behavior and/or maladaptive, inflexible decision-making and planning. The dorsal anterior cingulate cortex and insula may play important roles in switching between these VPFC and DPFC systems, which may contribute to the transition from suicide thoughts to behaviors. Future neuroimaging research of larger sample sizes, including global efforts, longitudinal designs, and careful consideration of developmental stages, and sex and gender, will facilitate more effectively targeted preventions and interventions to reduce loss of life to suicide.

Psychopharmacology of Suicide

Despite the psychotherapeutic and pharmacotherapeutic advances in the treatment of depressive, anxiety, and psychotic disorders over the past several decades, the suicide rate in the United States has increased over the past 18 years. Medications are safer and more difficult to use in overdosing, but not necessarily more efficacious in bringing about complete remission of symptoms. The current article focuses on the theories and psychosocial and neurobiological correlates of suicide with the intent of formulating intervention strategies to prevent suicide. Particular attention is on medications that may contribute to suicidal ideation and behaviors and those that show evidence of reducing the risk of suicide. [Journal of Psychosocial Nursing and Mental Health Services, 57(12), 9-14.].

Are relationships between impulsivity and depressive symptoms in adolescents sex-dependent?

Introduction

Both depressive symptomology and impulsivity are common during adolescence and are associated with various negative life outcomes. The potential sex-dependent nature of relationships between these constructs needs further exploration in order to understand their complexities. This cross-sectional study examined how levels of these constructs may differ by sex. Additionally, we investigated whether sex moderates relationships between adolescents' depression symptoms and different facets of impulsivity.

Methods

156 adolescents (M_age = 17.37, SD = 1.91, 59% female) completed self-report measures of their demographics, depression symptoms, and impulsivity. Multiple Analysis of Covariance (MANCOVA) assessed mean differences in depression symptoms and impulsivity by sex and race/ethnicity. Moderation analyses examined how sex may indirectly affect relationships between depression symptoms to predict attentional, motor, and non-planning impulsivity facets, as well as overall trait impulsivity.

Results

Correlations between depression symptoms and impulsivity scores were significant. Baseline depression symptoms were significantly higher among females (M = 9.53) compared to males (M = 6.68). Moderation effects of sex were not significant for attentional, motor, or overall trait impulsivity. However, sex moderated relations between depression symptoms and non-planning impulsivity, such that adolescent males showed higher levels of non-planning impulsivity when they reported high levels of depressive symptoms (B = .32, p < .01). This relationship was not significant for females.

Conclusions

While adolescent females may be more prone to depression, adolescent males may be more likely to experience non-planning impulsivity when experiencing symptoms of depression. The results of this study extend the literature regarding sex differences in vulnerabilities between these constructs. We suggest interventions targeting non-planning impulsivity may be especially salient for adolescent males reporting high levels of depressive symptoms.

Differentiation between young adult Internet addicts, smokers, and healthy controls by the interaction between impulsivity and temporal lobe thickness

BACKGROUND AND AIMS

Internet addiction is a non-substance-related addiction disorder with progressively growing prevalence. Internet addiction, like substance-related addictions, has been linked with high impulsivity, low inhibitory control, and poor decision-making abilities. Cortical thickness measurements and trait impulsivity have been shown to have a distinct relationship in addicts compared to healthy controls. Thus, we test whether the cortical correlates of trait impulsivity are different in Internet addicts and healthy controls, using an impulsive control group (smokers).

METHODS

Thirty Internet addicts (15 females) and 60 age- and gender-matched controls (30 smokers, all young adults aged 19-28 years) were scanned using a 3T MRI scanner and completed the Barratt Impulsiveness Scale.

RESULTS

Internet addicts had a thinner left superior temporal cortex than controls. Impulsivity had a significant main effect on the left pars orbitalis and bilateral insula, regardless of group membership. We identified divergent relationships between trait impulsivity and thicknesses of the bilateral middle temporal, right superior temporal, left inferior temporal, and left transverse temporal cortices between Internet addicts and healthy controls. Further analysis with smokers revealed that the left middle temporal and left transverse temporal cortical thickness change might be exclusive to Internet addiction.

DISCUSSION

The effects of impulsivity, combined with a long-term exposure to some specific substance or stimuli, might result in different natures of relationships between impulsivity and brain structure when compared to healthy controls.

CONCLUSION

These results may indicate that Internet addiction is similar to substance-related addictions, such that inefficient self-control could result in maladaptive behavior and inability to resist Internet use.

Gray and white matter differences in adolescents and young adults with prior suicide attempts across bipolar and major depressive disorders

BACKGROUND

Findings regarding brain circuitry abnormalities in suicide attempters (SAs) converge across bipolar disorder (BD) and major depressive disorder (MDD), the most common disorders observed in suicides. These abnormalities appear to be present during adolescence/young adulthood when suicide rates increase steeply, and suicide is a leading cause of death in this age group. Identification of brain circuitry common to adolescent/young adult SAs with BD and MDD is important for generating widely effective early prevention strategies. We examined brain circuitry in SAs in adolescents/young adults across these two disorders.

METHODS

Eighty-three participants (ages 14-25 years), 46 with BD (21 SAs) and 37 with MDD (19 SAs), underwent structural and diffusion-weighted magnetic resonance scanning. Whole-brain analyses compared gray matter (GM) volume and white matter (WM) fractional anisotropy (FA) between SAs and non-suicide attempters (NSAs) across and within BD and MDD (p < 0.005).

RESULTS

Across and within BD and MDD, SAs showed differences compared to NSAs in ventral prefrontal cortex (PFC) GM volume and fronto-limbic (including uncinate fasciculus (UF)) WM FA. Exploratory analyses showed additional within-disorder differences for BD SAs in dorsolateral PFC (dlPFC) and hippocampus GM volume and UF FA, and for MDD SAs dorsomedial and dlPFC GM and dorsal frontal WM. However, there was no significant interaction between suicide attempt status and diagnosis.

LIMITATIONS

Modest sample size.

CONCLUSIONS

Common fronto-limbic gray and white matter alterations in adolescent/young adult SAs are potential targets for suicide prevention strategies across mood disorders. Preliminary findings of disorder-specific regional findings could suggest diagnostic-specific optimal targets may exist.

Genetics of self-reported risk-taking behaviour, trans-ethnic consistency and relevance to brain gene expression

Risk-taking behaviour is an important component of several psychiatric disorders, including attention-deficit hyperactivity disorder, schizophrenia and bipolar disorder. Previously, two genetic loci have been associated with self-reported risk taking and significant genetic overlap with psychiatric disorders was identified within a subsample of UK Biobank. Using the white British participants of the full UK Biobank cohort (n = 83,677 risk takers versus 244,662 controls) for our primary analysis, we conducted a genome-wide association study of self-reported risk-taking behaviour. In secondary analyses, we assessed sex-specific effects, trans-ethnic heterogeneity and genetic overlap with psychiatric traits. We also investigated the impact of risk-taking-associated SNPs on both gene expression and structural brain imaging. We identified 10 independent loci for risk-taking behaviour, of which eight were novel and two replicated previous findings. In addition, we found two further sex-specific risk-taking loci. There were strong positive genetic correlations between risk-taking and attention-deficit hyperactivity disorder, bipolar disorder and schizophrenia. Index genetic variants demonstrated effects generally consistent with the discovery analysis in individuals of non-British White, South Asian, African-Caribbean or mixed ethnicity. Polygenic risk scores comprising alleles associated with increased risk taking were associated with lower white matter integrity. Genotype-specific expression pattern analyses highlighted DPYSL5, CGREF1 and C15orf59 as plausible candidate genes. Overall, our findings substantially advance our understanding of the biology of risk-taking behaviour, including the possibility of sex-specific contributions, and reveal consistency across ethnicities. We further highlight several putative novel candidate genes, which may mediate these genetic effects.

Inter and intra-hemispheric structural imaging markers predict depression relapse after electroconvulsive therapy: a multisite study

Relapse of depression following treatment is high. Biomarkers predictive of an individual's relapse risk could provide earlier opportunities for prevention. Since electroconvulsive therapy (ECT) elicits robust and rapidly acting antidepressant effects, but has a >50% relapse rate, ECT presents a valuable model for determining predictors of relapse-risk. Although previous studies have associated ECT-induced changes in brain morphometry with clinical response, longer-term outcomes have not been addressed. Using structural imaging data from 42 ECT-responsive patients obtained prior to and directly following an ECT treatment index series at two independent sites (UCLA: n = 17, age = 45.41±12.34 years; UNM: n = 25; age = 65.00±8.44), here we test relapse prediction within 6-months post-ECT. Random forests were used to predict subsequent relapse using singular and ratios of intra and inter-hemispheric structural imaging measures and clinical variables from pre-, post-, and pre-to-post ECT. Relapse risk was determined as a function of feature variation. Relapse was well-predicted both within site and when cohorts were pooled where top-performing models yielded balanced accuracies of 71-78%. Top predictors included cingulate isthmus asymmetry, pallidal asymmetry, the ratio of the paracentral to precentral cortical thickness and the ratio of lateral occipital to pericalcarine cortical thickness. Pooling cohorts and predicting relapse from post-treatment measures provided the best classification performances. However, classifiers trained on each age-disparate cohort were less informative for prediction in the held-out cohort. Post-treatment structural neuroimaging measures and the ratios of connected regions commonly implicated in depression pathophysiology are informative of relapse risk. Structural imaging measures may have utility for devising more personalized preventative medicine approaches.

Correlation of impulsivity with self-harm and suicidal attempt: a community study of adolescents in Taiwan

OBJECTIVES

The aim of this study was to investigate differences and similarities in risk factors for deliberate self-harm (DSH) and suicidal attempt (SA), and the role of impulsivity among a group of community adolescents.

SETTING

This is a cross-sectional study conducted at high schools in Northern Taiwan.

DATA AND PARTICIPANTS

We recruited grade 1 students from 14 high schools. A total of 5879 participants (mean age 16.02 years, female adolescents: 57.7%) completed the online assessment.

OUTCOME MEASURES

Participants completed online questionnaires about sociodemographic data, suicidality, history of DSH and SA, depressed mood, self-esteem, social support, family discord, impulsivity (Barratt Impulsiveness Scale Version 11 (BIS-11)) and the use of alcohol, tobacco and illicit drugs. A subsample was interviewed about lifetime SA, and the results were compared with those from the online questionnaires.

RESULTS

In our sample, 25% of the students had lifetime DSH and 3.5% had lifetime SA. Two hundred and seventy-two students received face-to-face interviews. The concordance between the online questionnaires and interviews in terms of ascertaining cases of SA was moderate (concordance rate 82.76%; kappa value 0.59). Similar risk factors for DSH/SA among the whole sample included female gender, lower academic performance, depression, substance use (tobacco and alcohol) and low self-esteem. The BIS-11 score was correlated with DSH. Factor 3 score of the BIS-11 (novelty seeking) was correlated with DSH in both boys and girls, whereas factor 2 score (lack of self-control) was correlated with SA in boys. Social support was a protective factor against SA among the female adolescents. Gender modulated the association of impulsivity and DSH/SA. Associations between impulsivity and DSH and SA were particularly strong among boys.

CONCLUSIONS

Risk factors for DSH and SA were similar, but not identical. Early identification of those at risk and appropriate interventions may be helpful.