ADHD includes three main types: predominantly inattentive presentation, predominantly hyperactive-impulsive presentation, and combined presentation. While ADHD is often diagnosed in childhood, many individuals continue to experience symptoms into adolescence and adulthood. Early diagnosis and effective treatment are key to improving functioning and self-esteem.

Common symptoms include difficulty sustaining attention, frequent careless mistakes, forgetfulness, trouble organizing tasks, excessive talking, fidgeting or restlessness, impatience, difficulty waiting turns, and interrupting others. In adults, symptoms may appear as chronic disorganization, time management challenges, impulsive decision-making, and emotional dysregulation.