 Attention Deficit Hyperactivity Disorder ADHD is a common childhood psychiatric condition, which often persists into adolescence. In adolescence ADHD is associated with poor academic, social, and emotional functioning, other psychiatric problems, substance abuse, and antisocial behaviour. Although medication effectively reduces symptoms such as hyperactivity and inattention, it does not directly address academic, social, emotional, and behavioural problems. Overcoming these would require building skills in organization, time management, problem solving, emotional modulation, stress management and interpersonal rapport. Yet, psychosocial treatments targeting such skills in adolescents with ADHD have been little studied and are scarce in the community. The proposed study will evaluate cognitive behavioural and skills training therapy CBTS for adolescents with ADHD. Adolescents will decide whether they want to take medication to treat their ADHD symptoms. If they choose to be on medication, they will be stabilized on optimized medication and randomly assigned to 12 sessions of either manualized group cognitive behavioral and skills training therapy CBTS or manualized supportive group therapy SGT. An additional treatment-as-usual group will also be included. CBTS will focus on skill acquisition in common problem areas for adolescents with ADHD, such as organization and time management, distractibility, impulsivity, and social skills. A coach will call each participant twice a week to help practice the learned skills. 