These three types constitute a risk group which needs given attention. In particular the cocainists state that personal problems were the reason for starting to take the drug. It was in an effort to limit these negative effects of cocaine that some respondents started taking heroin. Sniffers have far fewer problems with cocaine use than respondents who base, inject or 'chase the dragon' - 36 per cent versus 92 per cent in the period of heaviest use. All injectors are heroin users, whereas some of the respondents who only use cocaine also base.
Sniffers are less often addicted than the other respondents.
There is no difference between opiate users and non opiate users who-use the same method as far as the occurrence or the nature of problems is concerned. The idea is prevalent that problems with cocaine, especially addiction problems, occur only after a long period of use. The addiction aspect of cocaine should in this respect correspond more to alcohol addiction than to heroin addiction. This lack of associations also holds for the relationship between duration of use and the sort of problems occurring. Significant differences are only noted when a distinction is drawn between opiate and non opiate users.