Mortality in patients with dependence on prescription drugs

In 1974 we started a follow-up of patients with different psychoactive substance use disorders (PSUD) according to DSM-III; 2082 cases out of 2127 were analyzed; 1370 patients had taken legal drugs (i.e. prescription drugs and/or over-the-counter drugs); 444 patients suffered from abuse or dependence of legal drugs alone; 678 combined legal drugs and ethanol, and 248 cases combined legal and illegal drugs, often together with ethanol. A group of 712 alcoholics were included for comparison. Mean time under observation was 6.5 +/- 5.4 years, and 269 patients died. Mortality and survival were calculated and compared with expected survival from the normal population of the former Federal Republic of Germany. Mortality in all subgroups of PSUD was increased, the standardized mortality ratio (SMR) for patients on legal drugs alone being 2.1. Patients with legal plus illegal drugs had a SMR as high as 20.7; those with legal drugs plus ethanol 3.4; and alcoholics 4.2. The increased mortality seemed to be constant over the years. Mortality decreased in patients with stable abstinence. There was no clear sex difference. Abuse had a better prognosis than dependence. An estimation of potential life lost by the different PSUDs was attempted. Patients on legal drugs died from suicides, malignancies or accidents (including intoxication). In alcoholics or patients on legal drugs plus ethanol malignoma, liver cirrhosis, accident and suicide were the most prominent causes of death.