The subjective effects of cocaine: relationship to years of cocaine use and current age.

BACKGROUND: Little is known about whether the duration of cocaine use or an individual's age may influence the acute effects of cocaine, patterns of use, and specific treatment needs. OBJECTIVES: This post hoc analysis determined whether the duration of cocaine use or current age influenced the acute subjective response to cocaine. Data from four smoked cocaine self-administration laboratory studies were combined and analyzed to determine whether the subjective effects of a 25-mg smoked cocaine dose varied as a function of years of cocaine use or current age. METHODS: Thirty-six nontreatment-seeking healthy cocaine users (ages 32-49) were admitted to studies lasting from 12 to 105 days. Participants rated the subjective effects of each cocaine dose from 0 to 100 by completing a computerized self-report visual analogue scale (VAS). The main outcome measures were the change in VAS ratings between a baseline placebo dose and the first 25-mg dose of smoked cocaine. RESULTS: No significant relationship was found between the subjective effects of cocaine and years of cocaine use (mean 20.9, range 5-30) or current age (mean 41.1, range 32-49). CONCLUSION: Among long-term cocaine users between the ages of 32 and 49, the acute subjective effects of cocaine did not vary as a function of years of cocaine use or current age. SCIENTIFIC SIGNIFICANCE: These data fail to support the incentive sensitization theory for addiction by Robinson and Berridge, as cocaine "liking" and "wanting" remained the same regardless of age or years of cocaine use.