Psychiatric disorders and attempted suicide among adolescents with substance use disorders

Abstract

Objective: To determine the effects of psychiatric disorders on attempted suicide among adolescents with substance use disorders (SUD). Methods: Age of onset for psychiatric disorders, age of first suicide attempt, and the relationship of psychiatric disorder with attempted suicide were investigated in a sample of 503 adolescents with DSM-IV defined SUD (age range: 12.2–19.0 years). Results: Males who attempted suicide had a significantly earlier onset of alcohol use disorders (AUD) and significantly more mood, AUD, and disruptive behavior disorder symptoms compared to non-attempting males. Females who attempted suicide had a significantly earlier onset and higher counts of mood disorders and SUD symptoms compared to non-attempting females. Hazard analysis revealed that mood disorders represent the highest psychiatric risk for attempted suicide in both the genders. Attention deficit-hyperactivity disorder (ADHD) increased the risk for attempted suicide among males. The interaction of mood disorder and AUD increased the risk for attempted suicide among females. Conclusions: Clinicians should closely monitor SUD adolescents for suicide risk and be aware of gender differences for suicidal behavior based on course and severity of psychiatric disorder in this population.

Introduction

Alcohol and other substance use are among behaviors that place adolescents at greatest risk for suicidal behavior (Brent, 1995). Clinical and community studies have found alcohol use associated with attempted and completed suicide (Bukstein et al., 1993, Kelly et al., 2001, Wagner et al., 1996). Although it is less thoroughly investigated, severity of problematic alcohol use among adolescents has also been found to be associated with attempted suicide. In a longitudinal study, Reifman and Windle (1995) found increasing alcohol consumption-predicted future suicidal behaviors among adolescents.

While cannabis use is related to attempted suicide in preliminary analyses, its effect on attempted suicide is mitigated by controlling for socio-demographic and clinical variables such as mood disorders (Beautrais et al., 1999, King et al., 2001). Some studies have found cocaine use disorders and increased use of sedatives to be associated with attempted suicide among adolescents (Garnefeski and deWilde, 1998, Kelly et al., 2002, Kirmayer et al., 1998). Kelly et al. (2002) used a case-control method and found cocaine, hallucinogen, and inhalant use disorders associated with attempted suicide among adolescents with psychiatric disorders. Nevertheless, findings on the relationships of substance use disorder (SUD) with attempted suicide have been somewhat inconclusive because there are few studies of suicidal behavior in large samples of adolescents with SUD.

Comorbidity increases risk for suicidal behavior, particularly mood disorders with SUD (Brent et al., 1993a, Brent et al., 1993b; Lewinsohn et al., 1995, Lewinsohn et al., 1995) and disruptive behavior disorders with SUD (Marttunen et al., 1994). Investigations with clinical samples have found disruptive behavior disorders to be predictive of attempted and completed suicide (Groholt et al., 2000, Marttunen et al., 1994, Renaud et al., 1999), although it is not clear that disruptive behavior disorders independently contribute to adolescent suicidal behavior (Gould et al., 1998). Gould et al. (1998) investigated suicidal ideation and attempts in a well-designed epidemiologic study and concluded that substance use disorders may mediate the relationship between disruptive behavior disorders and suicidal behavior in adolescents. However, there is little detailed information on the connection between disruptive behavior disorders, substance use, and suicidal behavior because there is little in-depth research of psychiatric disorders and suicidal behavior among adolescents with substance use disorders. To our knowledge, for example, there have been no investigations of the course and severity of substance-related and non-substance related psychiatric disorders among suicidal adolescents with substance use disorders.

One area of investigation that has generally been neglected concerning suicidal adolescents is age of onset of psychiatric disorders in relation to suicidal behavior. Even well-designed prospective studies (e.g. Brent et al., 1993a, Brent et al., 1993b; Reinherz et al., 1995), considered by Lewinsohn et al. (1994) to be the best method for predicting attempted suicide among adolescents, have not addressed the age of onset of psychiatric disorders among suicidal adolescents with substance use disorders. Nor have there been investigations as to whether differences exist between suicidal and non-suicidal youth with SUD on age of onset for the most important clinical risks, e.g. mood disorders. This is critical information that could help clinicians to identify adolescents who may be on a path to suicidality early in treatment.