Assessment and Treatment of Stimulant Problems Professor Michael Gossop, National Addiction Centre, The Maudsley/Institute of Psychiatry, London. It has been suggested that the treatment of stimulant drug problems is an especially difficult issue. On various occasions, it has been suggested that such problems may be especially severe, resistant to change, or require the development and introduction of new treatment services and methods. In part, such views are due to a failure to understand the nature of the problems associated with the use of stimulant drugs. A fundamental distinction should be made between drug consumption behaviours (type of drug, frequency of use, amount taken), problems (acute medical problems, damage to physical or mental health, accidental injury), and dependence (feelings of compulsion to use, impaired control over drug use). These three dimensions should be seen as being conceptually separate, though in practice they are often related. The distinction between these dimensions forms an essential part of the assessment process. The clinical response to stimulant problems is no different, in most respects, from responses to other types of drug problems. Firstly, it is important to take account of the fact that most drug users seeking treatment do not confine their drug taking to single substances. In almost all cases, they are multiple drug users. Within these patterns of multiple drug use, certain substances are more likely to lead to problems than others. But it is seldom useful to focus too strongly upon substances: a properly conducted assessment should also identify the problems and needs of the user. This talk presents data on stimulant use problems and outcomes from a national UK study of treatment effectiveness (NTORS). Data are presented to show the nature and extent to which changes in the use of stimulants and other drugs have occurred within the UK. Such changes may take place with considerable rapidity; they may occur in localised areas; and they may involve transitions in routes of drug administration, which can have important implications with regard to the development of different types and severities of problems. Results from NTORS are presented for amphetamine type drugs and for cocaine (both crack cocaine and powder cocaine). Users of these drugs are more likely to seek treatment in residential programmes. The results show substantial clinical improvements after treatment. Improvements were found across a range of problem behaviours, including reduced illicit drug use, reduced injection risk behaviour, improved health, and reductions in acquisitive crime and drug selling. One area for concern was the lack of change in alcohol consumption and in continued excessive drinking after treatment. These results do not support the view that the treatment of stimulant users is a cause for pessimism, and indicate that a range of important treatment benefits can be obtained from the treatment of stimulant users within existing services. However, the results should not be taken to imply that any type of treatment will lead to improved outcomes. It is important to differentiate between types of intervention, choice of treatment goal, treatment setting, and treatment intensity as factors which influence treatment effectiveness and patient outcome. These issues are discussed.