(mainly opiate use) range from 7 to 25 percent proportionate mortality3 (Flavin et al., 1990). Molnar and colleagues (2001) estimated the PAR for serious suicide attempts among substance abusers (including alcohol) to be 30.2 percent for females and 52.9 percent for males. The vast majority of studies focus either on alcohol disorders alone or combine alcohol and other substance abuse disorders in their analyses. Murphy (2000) in a recent review argues that such an approach is warranted because of the common co-morbidities and the similarities among those with alcohol use disorders and those with illicit substance use disorders. On the other hand, others find clinical factors that distinguish those who abuse illicit substances from those who abuse alcohol (Porsteinsson et al., 1997; Vaillant, 1966).
Substance abusers frequently have comorbid Axis I and II disorders. A cross-national investigation found that mood and anxiety disorders are often comorbid in substance-abusing individuals, and that of the Axis II disorders, conduct disorder and antisocial personality disorder are at increased prevalence in this population (Merikangas et al., 1998). Almost 18 percent of individuals with substance use disorders (non-alcohol) have anti-social personality disorder (Kessler et al., 1994), while 10–30 percent of treatment-seeking cocaine abusing and opioid dependent individuals have comorbid depression (Weiss and Hufford, 1999). The relationship of substance abuse disorders and comorbid psychiatric diagnoses to suicidal behavior is complex, since it is often unclear in what order the conditions arose, what causal links exist, and whether other characteristics of psychology, biology or social circumstance may mediate the relationships.
The same suicide risk factors are found in substance abusers as in other populations: family psychopathology (especially maternal depression), hopelessness, comorbid disorders, use of multiple substances, and poorer psychosocial functioning (Flavin et al., 1990). Impulsivity (Block et al., 1988) is associated with increased risk for developing substance use disorders, as are novelty-seeking/impulsive personality traits (see section below) (Fergusson and Lynskey, 1996; Fergusson et al., 2000). In addition to the associated risk factors, individuals who abuse substances often diminish their protective social networks, secondary to their drug-related behaviors (Vaillant and Blumenthal, 1990).