ADHD in adulthood is a prevalent and impairing disorder. While medications have been effective in treating adult ADHD, the majority of individuals treated with medications have residual symptoms that require additional skills and symptom management strategies. Except for the intervention described in this series, there have been virtually no tested psychological interventions for clients with adult ADHD to date. Used in conjunction with the corresponding Workbook, this Therapist Guide offers effective treatment strategies that follow an empirically-supported treatment approach. It provides clinicians with effective means of teaching clients skills that have been scientifically tested and shown to help adults cope with ADHD. The step-by-step, session-by-session descriptions are a practical resource for therapists who deliver the treatment to clients with ADHD. Together, the therapist guide and client workbook contain all of the information and materials necessary to deliver this treatment in the context of individual outpatient cognitive-behavioural therapy.