Other Specified Attention-Deficit/Hyperactivity Disorder 65
Personality disorders. In adolescents and adults, it may be difficult to distinguish ADHD
from borderline, narcissistic, and other person ality disorders. All these disorders tend to
share the features of disorganization, social  intrusiveness, emotional dysregulation, and
cognitive dysregulation. Howe ver, ADHD is not characterized by fear of abandonment,
self-injury, extreme ambivalence, or other fe atures of personality disorder. It may take
extended clinical observation, informant interview, or detailed history to distinguish im-
pulsive, socially intrusive, or inappropriate behavior from narcissist ic, aggressive, or dom-
ineering behavior to make this differential diagnosis.
Psychotic disorders. ADHD is not diagnosed if the symp toms of inattention and hyperac-
tivity occur exclusively during the course of a psychotic disorder.
Medication-induced symptoms of ADHD. Symptoms of inattention, hyperactivity, or
impulsivity attributable to the use of medication (e.g., bron chodilators, isoniazid, neuro-
leptics [resulting in akathisia], thyroid replacement medication) are diagnosed as other
specified or unspecified other (or un known) substance–related disorders.
Neurocognitive disorders. Early major neurocognitive disorder (dementia) and/or
mild neurocognitive disorder are not known to  be associated with ADHD but may present
with similar clinical features. These conditions are distinguished from ADHD by their late
onset.
Comorbidity
In clinical settings, comorbid  disorders are frequent in individuals whose symptoms meet
criteria for ADHD. In the general population, oppositional defiant di sorder co-occurs with
ADHD in approximately half of children wi th the combined presentation and about a
quarter with the predominantly inattentive presentation. Conduct disorder co-occurs in