Writing of her practice, Cameron (in press) points out that as with clients of other kinds, for clients whose use of mood-altering substances is problematic constructive change begins when the client perceives the counsellor to be genuinely empathic and unconditionally accepting. However, there is an ever-present danger that, as the client becomes more aware of underlying psychological tension, the internal pressure to use again, or use more, will become overwhelming. The client who stops or reduces drug or alcohol use, and takes time to adjust to this before exploring very sensitive issues, gives themselves the best chance of working through these without resuming their previous habit. Understanding and respecting the client's process of coming to terms with a substance problem is an essential foundation to offering a relationship that is neither directive nor collusive. As with any client group, working with people who experience their substance use as problematic requires only that the necessary and suf®cient conditions are consistently present. Any difference lies in the therapist and how the therapist ensures that they can congruently offer unconditional positive regard and empathic understanding. This may involve making judgements about the nature of contact possible for them and dealing with their own reactions to (and judgement of ) people who use moodaltering substances.