The goal of supportive-expressive (SE) psychotherapy is to help the client achieve mastery over their difficulties, gain self-understanding, and practice self-control over habitual drug use and related problems. The theory behind the SE approach emphasizes the formative influence of life experiences on the development of personality and on the genesis of problems, including habitual cannabis use. Cannabis users' most frequently reported psychological problems concerned feelings of insecurity, low self-image, extreme introversion, depression, and relationship problems. This chapter illustrates some of the SE psychotherapy processes, and how they lead to positive change. As interpersonal, social, intimacy, and work difficulties are often reported by cannabis users, SE dynamic psychotherapy approach may be particularly salient as it focuses not only on drug use, but also on the relationship between use and interpersonal problems. To date, evidence in the psychotherapy field suggests that longer treatment leads to better outcomes.