Matthew K. Nock

Cross-National Prevalence and Risk Factors for Suicidal Ideation, Plans, and Attempts

BACKGROUND Suicide is a leading cause of death worldwide; however, the prevalence and risk factors for the immediate precursors to suicide - suicidal ideation, plans and attempts - are not wellknown, especially in low- and middle-income countries. AIMS To report on the prevalence and risk factors for suicidal behaviours across 17 countries. METHOD A total of 84 850 adults were interviewed regarding suicidal behaviours and socio-demographic and psychiatric risk factors. RESULTS The cross-national lifetime prevalence of suicidal ideation, plans, and attempts is 9.2% (s.e.=0.1), 3.1% (s.e.=0.1), and 2.7% (s.e.=0.1). Across all countries, 60% of transitions from ideation to plan and attempt occur within the first year after ideation onset. Consistent cross-national risk factors included being female, younger, less educated, unmarried and having a mental disorder. Interestingly, the strongest diagnostic risk factors were mood disorders in high-income countries but impulse control disorders in low- and middle-income countries. CONCLUSION There is cross-national variability in the prevalence of suicidal behaviours, but strong consistency in the characteristics and risk factors for these behaviours. These findings have significant implications for the prediction and prevention of suicidal behaviours.

Non-suicidal self-injury among adolescents: Diagnostic correlates and relation to suicide attempts

Non-suicidal self-injury (NSSI) is a prevalent behavioral problem, yet many fundamental aspects of NSSI remain unknown. This case series study reports on the diagnostic correlates of adolescents with a recent history of NSSI and examines the relation between NSSI and suicide attempts. Data are from clinical interviews with 89 adolescents admitted to an adolescent psychiatric inpatient unit who engaged in NSSI in the previous 12 months. Results revealed that 87.6% of adolescents engaging in NSSI met criteria for a DSM-IV Axis I diagnosis (M=3.0, S.D.=2.2, range=0 to 8 diagnoses), including externalizing (62.9%), internalizing (51.7%), and substance use (59.6%) disorders. Most adolescents assessed also met criteria for an Axis II personality disorder (67.3%). Overall, 70% of adolescents engaging in NSSI reported a lifetime suicide attempt and 55% reported multiple attempts. Characteristics of NSSI associated with making suicide attempts included a longer history of NSSI, use of a greater number of methods, and absence of physical pain during NSSI. These findings demonstrate the diagnostic heterogeneity of adolescents engaging in NSSI, highlight the significant overlap between NSSI and suicide attempts, and provide a point of departure for future research aimed at elucidating the relations between non-suicidal and suicidal self-injury.

A functional approach to the assessment of self-mutilative behavior.

This study applied a functional approach to the assessment of self-mutilative behavior (SMB) among adolescent psychiatric inpatients. On the basis of past conceptualizations of different forms of self-injurious behavior, the authors hypothesized that SMB is performed because of the automatically reinforcing (i.e., reinforced by oneself; e.g., emotion regulation) and/or socially reinforcing (i.e., reinforced by others; e.g., attention, avoidance-escape) properties associated with such behaviors. Data were collected from 108 adolescent psychiatric inpatients referred for self-injurious thoughts or behaviors. Adolescents reported engaging in SMB frequently, using multiple methods, and having an early age of onset. Moreover, the results supported the structural validity and reliability of the hypothesized functional model of SMB. Most adolescents engaged in SMB for automatic reinforcement, although a sizable portion endorsed social reinforcement functions as well. These findings have direct implications for the understanding, assessment, and treatment of SMB.

Delineating mechanisms of change in child and adolescent therapy: methodological issues and research recommendations

BACKGROUND Mechanisms of therapeutic change are rarely studied in child and adolescent therapy. Our central thesis is that the study of mechanisms of treatment is an excellent investment for improving clinical practice and patient care. Indeed, extending treatment trials to clinical settings, without complementary research that studies why and how treatment works, could have great limitations. METHOD In this article, we discuss the importance of studying mechanisms, the logical and methodological requirements, and why almost no studies to date provide evidence for why or how treatment works. Standard statistical practices (tests of mediation) and designs (randomized controlled clinical trials) contribute greatly to outcome research but have little to say about mechanisms given the way they are commonly used. CONCLUSIONS The article ends with recommendations to guide research on mechanisms of therapeutic change.

Mental Disorders, Comorbidity and Suicidal Behavior: Results from the National Comorbidity Survey Replication

Mental disorders are among the strongest predictors of suicide attempts. However, little is known regarding which disorders that are uniquely associated with suicidal behavior because of high levels of psychiatric comorbidity. We examined the unique associations between individual disorders and subsequent suicidal behavior (suicide ideation, plans and attempts) using data from the National Comorbidity Survey Replication, a nationally representative household survey of 9282 US adults. Results revealed that approximately 80% of suicide attempters in the United States have a temporally prior mental disorder. Anxiety, mood, impulse-control and substance use disorders all significantly predict subsequent suicide attempts in bivariate analyses (odds ratios (OR)=2.7–6.7); however, these associations decrease substantially in multivariate analyses controlling for comorbidity (OR=1.5–2.3) but remain statistically significant in most cases. Disaggregation of the observed effects reveals that depression predicts suicide ideation, but not suicide plans or attempts among those with ideation. Instead, disorders characterized by severe anxiety/agitation (for example, post-traumatic stress disorder) and poor impulse control (for example, conduct disorder, substance use disorders) predict which suicide ideators who go on to make a plan or attempt. These results advance understanding of the unique associations between mental disorders and different forms of suicidal behavior. Future research must further delineate the mechanisms through which people come to think about suicide and progress from suicidal thoughts to attempts.

Contextual Features and Behavioral Functions of Self-Mutilation Among Adolescents

Adolescent self-mutilative behavior (SMB) is a pervasive and dangerous problem, yet factors influencing the performance of SMB are not well understood. The authors examined the contextual features and behavioral functions of SMB in a sample of 89 adolescent psychiatric inpatients. SMB typically was performed impulsively, in the absence of physical pain, and without the use of alcohol or drugs. Moreover, analyses supported the construct validity of a functional model in which adolescents reported engaging in SMB for both automatic and social reinforcement. Considering the functions of SMB clarified the relations between SMB and other clinical constructs reported in previous studies such as suicide attempts, posttraumatic stress, and social concerns and has direct implications for the assessment and treatment of SMB.

Prevalence, Correlates, and Treatment of Lifetime Suicidal Behavior Among Adolescents: Results From the National Comorbidity Survey Replication Adolescent Supplement

CONTEXT Although suicide is the third leading cause of death among US adolescents, little is known about the prevalence, correlates, or treatment of its immediate precursors, adolescent suicidal behaviors (ie, suicide ideation, plans, and attempts). OBJECTIVES To estimate the lifetime prevalence of suicidal behaviors among US adolescents and the associations of retrospectively reported, temporally primary DSM-IV disorders with the subsequent onset of suicidal behaviors. DESIGN Dual-frame national sample of adolescents from the National Comorbidity Survey Replication Adolescent Supplement. SETTING Face-to-face household interviews with adolescents and questionnaires for parents. PARTICIPANTS A total of 6483 adolescents 13 to 18 years of age and their parents. MAIN OUTCOME MEASURES Lifetime suicide ideation, plans, and attempts. RESULTS The estimated lifetime prevalences of suicide ideation, plans, and attempts among the respondents are 12.1%, 4.0%, and 4.1%, respectively. The vast majority of adolescents with these behaviors meet lifetime criteria for at least one DSM-IV mental disorder assessed in the survey. Most temporally primary (based on retrospective age-of-onset reports) fear/anger, distress, disruptive behavior, and substance disorders significantly predict elevated odds of subsequent suicidal behaviors in bivariate models. The most consistently significant associations of these disorders are with suicide ideation, although a number of disorders are also predictors of plans and both planned and unplanned attempts among ideators. Most suicidal adolescents (>80%) receive some form of mental health treatment. In most cases (>55%), treatment starts prior to onset of suicidal behaviors but fails to prevent these behaviors from occurring. CONCLUSIONS Suicidal behaviors are common among US adolescents, with rates that approach those of adults. The vast majority of youth with suicidal behaviors have preexisting mental disorders. The disorders most powerfully predicting ideation, though, are different from those most powerfully predicting conditional transitions from ideation to plans and attempts. These differences suggest that distinct prediction and prevention strategies are needed for ideation, plans among ideators, planned attempts, and unplanned attempts.

Self-Injurious Thoughts and Behaviors Interview: Development, Reliability, and Validity in an Adolescent Sample

The authors developed the Self-Injurious Thoughts and Behaviors Interview (SITBI) and evaluated its psychometric properties. The SITBI is a structured interview that assesses the presence, frequency, and characteristics of a wide range of self-injurious thoughts and behaviors, including suicidal ideation, suicide plans, suicide gestures, suicide attempts, and nonsuicidal self-injury (NSSI). This initial study, based on the administration of the SITBI to 94 adolescents and young adults, suggested that the SITBI has strong interrater reliability (average kappa = .99, r = 1.0) and test-retest reliability (average kappa = .70, intraclass correlation coefficient = .44) over a 6-month period. Moreover, concurrent validity was demonstrated via strong correspondence between the SITBI and other measures of suicidal ideation (average kappa = .54), suicide attempt (kappa = .65), and NSSI (average kappa = .87). The authors concluded that the SITBI uniformly and comprehensively assesses a wide range of self-injury-related constructs and provides a new instrument that can be administered with relative ease in both research and clinical settings.

Cross-national analysis of the associations among mental disorders and suicidal behavior: findings from the WHO World Mental Health Surveys.

Using data from over 100,000 individuals in 21 countries participating in the WHO World Mental Health Surveys, Matthew Nock and colleagues investigate which mental health disorders increase the odds of experiencing suicidal thoughts and actual suicide attempts, and how these relationships differ across developed and developing countries.

Prevalence of and risk factors for suicide attempts versus suicide gestures: analysis of the national comorbidity survey

Definitions and classification schemes for suicide attempts vary widely among studies, introducing conceptual, methodological, and clinical problems. We tested the importance of the intent to die criterion by comparing self-injurers with intent to die, suicide attempters, and those who self-injured not to die but to communicate with others, suicide gesturers, using data from the National Comorbidity Survey (n = 5,877). Suicide attempters (prevalence = 2.7%) differed from suicide gesturers (prevalence = 1.9%) and were characterized by male gender, fewer years of education, residence in the southern and western United States; psychiatric diagnoses including depressive, impulsive, and aggressive symptoms; comorbidity; and history of multiple physical and sexual assaults. It is possible and useful to distinguish between self-injurers on the basis of intent to die.