Familial history of opium use and reported problems among opium addicts in Pakistan.

One-hundred and twenty-nine opiate addicts on a monthly maintenance regimen were studied. Subjects with a positive family history of opium use had an earlier age of onset than the subjects without a family history of opium use. Self-reported psychosocial problems resulting from opium use were documented in only seven subjects. Individuals who began opium use after 1979, when it became illegal to use the drug, had a significantly later age of onset than subjects who began before 1979, suggesting that negative legal sanctions can delay initiation of opium consumption.