An estimated 50 percent of people with ADHD also have other behavioral, emotional or academic problems that co-exist with the disorder. That can make diagnosis tricky. These other conditions also make living with ADHD even more difficult, because many of them hinder one’s ability to concentrate or control impulses. Approximately one out of four children with ADHD, for example, also have a learning disability, while many others have significant difficulty in school, including behavioral problems that disrupt their ability to learn in the classroom.

People with ADHD also are more likely to have speech and language disorders and health problems such as upper respiratory infections and allergies. Many are at increased risk for accidental injury. Still others show forms of antisocial behavior and may actually have what is called oppositional defiant disorder. These individuals can be obstinant, aggressive, verbally hostile and disobedient. A significant number of children with ADHD also may develop conduct disorder. They may lie, steal, skip school or become physically aggressive.

In contrast, others with ADHD experience extreme anxiety. They worry unnecessarily or feel undue stress. These individuals also are predisposed to depression and low self-esteem, which can have serious effects on the quality of their day-to-day lives and dealings with others. Teens with ADHD may be prone to alcohol and drug use and abuse.

A small number of people with ADHD also have Tourette syndrome, an uncommon disorder characterized by facial tics and other uncontrollable movements.

Careful evaluation is required to determine the best treatment for individuals with ADHD who have co-existing conditions, and to rule out diagnoses that mimic ADHD. Sleep disorders, for example, sometimes cause fatigue, irritability, anxiety, depression, aggressiveness and memory problems.

What's Related

• What if Someone You Know Has ADHD?
• Diagnosing ADHD/ADD in Adults
• What Is Attention Deficit Disorder?
• What Causes Attention Deficit Disorders?
• An Introduction to Attention Deficit Disorder
• Symptoms of Attention Deficit Disorder
• ADHD and Sleep
• Medications for Children
• Parent Coping Strategies for ADHD
• The ABCs of ADHD