Over the last century alcohol and suicide rates have co-varied in a number of countries. A precipitous drop in suicide rates in the United States (from 15.3 to 10.2 per 100,000 between 1910 to 1920) occurred during the period of most acute reduction of alcohol consumption (Lester, 1995). Reductions in alcohol consumption secondary to rationing in the 1950s in Sweden, and large increases in price in Denmark in the early part of the twentieth century both coincided with significant reductions in the suicide rates (Wasserman, 1992). In Finland, a significant positive correlation was observed between alcohol consumption and suicide rates for males aged 15–49 from 1950 to 1991, but not for older males (Makela, 1996). A study examining the relationship between alcohol consumption and suicide in Denmark, Finland, Norway, and Sweden for up to 50 years found significant relationships only in Sweden and Norway (Norstrom, 1988). No relationship was observed for Finland (Norstrom, 1988). The single largest reduction in male suicides in the last 30 years occurred during the Perestroika in the USSR during the second half of the 1980s. This reduction was seen in all 15 republics of the USSR, with the greatest decrease, from over 65 per 100,000 to less than 40 per 100,000 occurring in the Russian Republic from 1984 to 1986 (Wasserman et al., 1998). During this time, alcohol consumption was significantly reduced due to a broad, multi-level national campaign to reduce alcoholism and to immeasurably increased hope from the economic and social restructuring under Gorbachev (Wasserman and Varnik, 2001). Population-level observations are difficult to interpret, since it is not known if the variables of interest are correlated within individuals (see also Chapter 6). Possible confounding issues include income, divorce and unemployment (e.g., Makela, 1996).
In 1999 almost 15 million Americans used illicit drugs and 3.5 million were dependent on these substances (SAMHSA, 1999). Drug dependence has been experienced by 7.5 percent of the population, and drug use without dependency by 4.4 percent of the population (Kessler et al., 1994). Substance abuse prevalence is increasing among younger cohorts (Kessler et al., 1994).
Abuse of illicit substances, like alcohol abuse, is associated with increased risk for suicide and suicide attempts. Treated opiate abusers had a suicide attempt rate 4 times that of the community surveyed, with a lifetime prevalence of 17.3 percent (Murphy et al., 1983). Reported estimates for completed suicide associated with illicit substance abuse