Attention deficit hyperactivity disorder (ADHD) is characterized by a persistent pattern of attentional difficulties and/or hyperactive and impulsive behavior that is more severe than is typically seen in other people of the same age. To meet criteria for ADHD, a person must show a pattern of either inattention (e.g., failing to pay attention to details, easily distracted, often forgetful) or hyperactivity/impulsivity (e.g., fidgeting, excessive running or climbing in inappropriate situations, interrupting/intruding on others) for at least six months at a level that is severe enough to be unusual for their age. ADHD is usually first diagnosed in childhood.
Because ADHD and borderline personality disorder (BPD) share symptoms of impulsive behaviors, children (and adults) with BPD can be misdiagnosed with ADHD. In addition, the two disorders frequently co-occur, meaning that some people meet diagnostic criteria for both.
Sources:
American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders DSM-IV-TR Fourth Edition. American Psychiatric Association, 2000.
Friedel RO. Borderline Personality Disorder Demystified: An Essential Guide for Understanding and Living with BPD. Da Capo Press; 2004.
