Researchers study effect of ADHD on smoking cessation

Tobacco use is more prevalent and smoking cessation less likely among persons with Attention Deficit Hyperactivity Disorder (ADHD).

In a study of smokers with attention deficit and hyperactivity symptoms, those who exhibited elevated hyperactivity and impulsivity, with or without inattention, showed lower quit rates after 8 weeks than those with inattention symptoms alone or those without the ADHD symptoms. The study, now available online in Nicotine and Tobacco Research, could help smokers and physicians to better tailor cessation treatment for individuals with ADHD

"Greater understanding of the divergent associations that exist between the different kinds of ADHD have important public health consequences for smoking cessation and decreased tobacco-related mortality in this population," said the study's lead author Lirio Covey, Ph.D., professor of clinical psychology (in psychiatry) at Columbia University Medical Center and the New York State Psychiatric Institute.

"The effect of ADHD by itself on smoking cessation has rarely been examined; the effects of the individual ADHD symptoms on smoking cessation, even less so. To our knowledge, the effects of inattention or hyperactivity at baseline as separate domains of ADHD on cessation treatment outcome have never been examined," Dr. Covey reported.

During the initial, eight-week phase of a maintenance treatment study, 583 adult smokers, 43 of whom were identified with clinically significant ADHD symptom subtypes using the ADHD Current Symptom Scale, were treated with the medication buproprion (brand name Zyban®), the nicotine patch and regular cessation counseling. Compared to smokers without ADHD, smokers of both ADHD subtypes combined showed lower abstinence rates throughout the study.

Breakdown of the ADHD group by subtype, however, revealed a more complicated picture. The researchers found that by the end of the treatment, the proportion of abstainers among ADHD smokers with inattention were nearly identical to those without ADHD (55 percent compared to 54 percent, respectively).

By contrast, the ADHD subgroup with hyperactivity, with or without inattention, exhibited lower quit rates throughout the treatment period compared to smokers without ADHD, essentially finding that only in the presence of hyperactivity and impulsivity, were differences observed between smokers with or without ADHD symptoms.

"The knowledge gained from further study of how these early onset disorders of nicotine dependency and ADHD are related could lead to early prevention of either one or both of these conditions," concluded Dr. Covey. More research is needed to tease out why hyperactivity causes less cessation success.

The greater propensity to smoke and difficulty quitting among persons with mental illness is thought to play a role in the "hardening" phenomenon, or the increased resistance to smoking cessation among certain smokers.

Much evidence that nicotine improves attentiveness and performance deficits among persons with ADHD provides a "self-medicating" rationale for tobacco use among persons with ADHD Pre-clinical data showing that dopamine, a neurotransmitter relevant to attentional processes and impulse control, is released upon smoking, is consistent with the self-medication hypothesis.

ADHD is a neuropsychiatric condition that begins in early childhood and, in most cases, persists to adolescence and adulthood. The core symptom domains in ADHD are inattention and hyperactivity/impulsivity. ADHD has been sub-classified into three subtypes: predominantly inattention, predominantly hyperactivity/impulsivity, and combined inattention and hyperactivity/impulsivity.