One out of every 10 adult psychotherapy clients—or more—probably has attention deficit/hyperactivity disorder (ADHD). When psychotherapists miss the ADHD, treatment is frustrating and less effective. This book is for the general mental health professional who wishes to learn how to recognize, assess, and treat adult ADHD. Adults with ADHD are very different, developmentally and symptomatically, from children. ADHD affects adults of all races, gender identities, and backgrounds, and obvious hyperactivity is rarely part of the adult clinical picture. This book provides a full description of adult ADHD symptoms, based on the most current research, including executive functioning problems, emotional dysregulation, atypical reward sensitivity, and problems with time perception. Complete guidance to recognizing adult ADHD is provided, including behavior displayed during psychotherapy, developmental issues, educational challenges, and adaptive functioning problems. Depression, anxiety, self-image issues, and substance abuse are addressed, since these mental health problems are commonly associated with adult ADHD. Guidance is provided to help the mental health practitioner provide psychoeducation about cognitive differences in ADHD, which is essential for client self-acceptance and adaptive functioning. Common psychotherapy problems with ADHD clients are addressed, including chronic lateness to sessions, missed appointments, motivation problems, difficulties with homework, and tangentiality. The principles of cognitive-behavioral treatment of ADHD are provided, along with case examples to illustrate the implementation of these techniques. An overview of medications for ADHD is provided, including their benefits, contraindications, and side effects. Nontraditional treatments are reviewed for their effectiveness.