Attention-Deficit Hyperactivity Disorder, (ADHD), is an established childhood psychiatric disorder, and it is the present diagnosis for children with major difficulties in the core symptoms; impulsiveness, attention and hyperactivity. The disorder is known to persist into adulthood and create major problems in coping with everyday life. With ADHD follows a vast variety of other conditions, which burdens the ADHD individuals even more. The major cause for the disorder is in heritage but also other possible explanations will be discussed. The main treatment for ADHD is psycho stimulants, such as methylphenidate and amphetamine. ADHD is associated with substance abuse and several articles in this essay will provide support for that. Is substance abuse in ADHD individuals a form of self-medication in order to ameliorate the symptoms or is the increased risk for substance abuse due to the stimulant medications? In this essay, I will describe what ADHD is, present what are its known causes, summarize the treatments available for ADHD, and discuss the relationships between ADHD and substance abuse.