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The authors studied the use of alcohol by a sample of narcotics addicts (N=140) and by a sample of nonaddict nonalcoholics (N=100). They found that the addicts' use of alcohol prior to their use of heroin significantly exceeded that of the normal sample. However, the addicts' use of alcohol decreased as they became involved with heroin and did not increase during treatment.
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Brown et al. (1973) studied this question.
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