In this issue, Searight and colleagues¹ focus on an area of growing importance to primary care practitioners: the diagnosis and treatment of attention-deficit/hyperactivity disorder (ADHD) in adults. This disorder was once considered a childhood condition with few adult consequences, but it is now clear that a significant number of children with ADHD continue to have difficulties that persist into adolescence and adulthood. By the time patients with ADHD are in their mid-20s, follow-up studies show that the prevalence of continuing ADHD ranges from 4 percent¹ to 80 percent.² If a child has ADHD with no other psychiatric diagnoses (particularly conduct disorder or severe affective disorder) and no comorbid learning disabilities, the prognosis is likely to be benign. Conversely, if complicating psychiatric factors are present in addition to ADHD, the prognosis is more guarded and the patient stands a greater chance of having adult ADHD, substance abuse and personality disorder.

ADHD that persists into late adolescence and young adulthood is associated with a number of health risks. While driving, teenagers with ADHD have significantly more crashes, speeding tickets and license suspensions.³ Children with ADHD are more likely than their peers to smoke cigarettes; adults with ADHD more often smoke than those in control groups and report having significantly more difficulty quitting smoking.^4,5 Adults with ADHD have higher lifetime rates of psychoactive substance abuse disorders than control subjects.⁶

It is important to note that stimulant treatment of ADHD in childhood does not predispose patients to become substance abusers; indeed, the opposite is true. In a long-term follow-up study, Biederman and colleagues⁷ compared 117 teenagers with ADHD who had been treated with medication with 45 children with untreated ADHD and 344 control subjects. In adulthood, the rate of substance abuse disorders did not differ between the medication-treated ADHD group (13 percent) and the control group (10 percent), but it was significantly higher in the untreated ADHD group (33 percent). This was a statistically significant difference that persisted even after controlling for poverty, family history of substance abuse and conduct disorder.

Early treatment of childhood ADHD may play a role in protecting against the development of substance abuse disorders in this vulnerable population. It is possible that continuing treatment of adult ADHD may be imperative in preventing a range of dire health consequences.

The authors discuss the process of diagnosing adult ADHD, with particular emphasis on two critical factors: documenting childhood onset and examining for other psychiatric disorders. The first step is particularly important, as a diagnosis of adult ADHD cannot be made in its absence. As the authors point out, obtaining a history from the patient's parents or examining old school or medical records is critical. Occasionally, a patient who presents with a history of very good early school performance is now having problems in higher education or on the job. Such a patient may claim that superior intelligence compensated for ADHD when he or she was younger, but that he or she is now symptomatic because of the higher cognitive demands of the current environment. A family physician should refer such a patient for in-depth testing before beginning treatment.

Depression and anxiety disorders frequently impair concentration in adults and constitute the principal disorders in the differential diagnosis. Major depression typically is pervasive in the patient's life and is associated with neurovegetative signs (sleep, appetite and energy loss), as well as suicidal ideation or guilt. Patients with ADHD, in contrast, often have brief periods of irritability, frustration with life and poor temper control.

The authors discuss the wide range of psychopharmacologic interventions available for adults with ADHD. As with children, stimulants are the first-line treatment in adults, except when the ADHD patient has an active substance abuse problem. The physician should treat the patient with stimulants (i.e., amphetamine mixed salts [Adderall], dextroamphetamine [Dexedrine], methylphenidate [Ritalin]) before trying the nonstimulants (i.e., tricyclic antidepressants, bupropion [Wellbutrin]). Adults with ADHD may also benefit from cognitive behavior therapy, provided it focuses on developing higher level organization skills. Spouses may benefit from therapy that suggests what they can do to help organize their distracted partner.

Research into the neurobiology of ADHD is progressing steadily and may lead to improved treatment of this problematic condition. These authors have done a good job of concisely reviewing a complex area in which family physicians will play an expanding role.