افسردگی و مشکلات رفتار ضد اجتماعی به عنوان ارتباط برای رفتارهای مربوط به خودکشی در مکزیک

Abstract Suicide rates in Mexico have been rising steadily for several decades. This study examined the relationship of depressed mood and antisocial behavior problems with thoughts of death, suicide plans and attempts. Data from 22,966 individuals who participated in a population-based nationally-representative survey in Mexico were analyzed. After adjusting for covariates, all odds ratios for thoughts of death and suicidal behaviors were statistically significant in relation to antisocial behavior problems and depressed mood, both moderate and severe. Multiplicative effects of depressed mood and antisocial problems were found, with comorbid individuals showing increased risk of thoughts of death and suicidal plans and attempts, compared to individuals displaying none. Possible explanations, particularly for the multiplicative effect of both mood and problem behaviors on suicide-related behaviors, are discussed in the context of prior findings and directions for future research.

1. Introduction In terms of global mortality and burden of disease, suicide has been identified as the 14th leading cause of death in 2002, and is projected to rise to take the 12th spot by 2030 (Mathers and Loncar, 2006). The World Health Organization (WHO) reported that an estimated one million deaths were due to suicide in 2000, translating to a global suicide rate of 16 deaths per 100,000 persons (World Health Organization, 2008). Self-inflicted injuries are among the top 20 leading causes of Disability Adjusted Life Years (DALYs) globally (World Health Organization, 2001). Hence it is crucial to identify determinants of suicide and implement interventions to reduce suicide rates worldwide. Mexico is no exception to these changing trends, having seen steady increases in the rate of completed suicide in the last several decades (Borges et al., 2006b), especially among youth. In a study where 28 countries were considered, the rise in Mexico’s suicide rates was one of the most dramatic (Bridge et al., 2006). In this context of increasing suicide mortality, the study of suicide-related behaviors (i.e. thoughts of death, plans and suicide attempts) is especially relevant. Suicide planning and attempts may be immediate precursors to death by suicide and independent risk factors of subsequent suicide attempts and completions. Even episodes that do not result in death can lead to serious, long-term consequences in one’s physical health, as well as can be an important cause of psychological suffering on the part of the individual and his or her family. Prior research in adults and adolescents in Mexico (Borges et al., 2005 and Borges et al., 2008b) has suggested that, besides depression, the so-called impulse control disorders may have special importance in the risk of suicide-related behaviors among Mexicans. Cross-national research among a series of developed and developing countries participating in the World Mental Health Surveys (Nock et al., 2008 and Nock et al., 2009a) have also pointed to differences in the role of psychiatric disorders and suicide-related behaviors in these two groups of nations. In the analyses conducted by Nock and colleagues, mood disorders were found to be the strongest predictor of suicidal behaviors in high-income countries, whereas in low- and middle-income countries DSM-IV impulse control disorders, such as conduct and oppositional defiant disorders, were more predictive. Two limitations are apparent in prior research in this area. First, most studies in samples of the general population are based on lifetime suicidal behaviors, while current or recent suicidal behaviors – of great importance for clinical and prevention purposes – has traditionally been understudied. While lifetime prevalences are an important starting point in understanding suicidal behavior, the fact that suicide risk varies across the lifespan makes the identification of recent behaviors more relevant for prevention (Borges et al., 2006a). Second, even though comorbidity is a main risk factor for suicidal behaviors (Kessler et al., 1999), few studies have looked at specific comorbidities among disorders. These are especially relevant issues as it is estimated that in the United States over 90 percent of those who take their lives to suicide had a diagnosable psychiatric disorder at the time of death, although this may not translate cross-culturally (Conwell et al., 1996, Harris and Barraclough, 1997 and Bhatia et al., 1987). Another limitation is that most studies fail to assess or account for two important risk factors for suicidal behaviors: alcohol and drug use disorders and traumatic life events, such as sexual abuse. And while much research has been conducted in developed countries, surprisingly few resources have been invested to assist in a better understanding of the risk and protective factors for suicide in developing nations.

8. Conclusion Moderate and severe depressed mood and antisocial behavior problems are strongly associated with all three suicide-related behaviors: thoughts of death, suicide plan and attempts, even after taking into account relevant sociodemographic characteristics, history of sexual abuse, and past year alcohol abuse/dependence and drug problems. Future research is needed to establish the temporality of these constructs in relation to suicidal behaviors, yet current evidence still supports the implementation and evaluation of clinical and psychosocial interventions that target depressed mood and ASBP in addition to suicidal behaviors for reduction of suicide mortality in Mexico. Funding Source This study was possible due to a grant from the Instituto Mexicano de la Juventud to Guilherme Borges.