The Reinforcing Mechanisms of Smoking in Adult ADHD

Phase 1

Completed

Brief Summary: Whereas the smoking prevalence rates in the general population are declining, rates among people diagnosed with attention-deficit hyperactivity disorder (ADHD) continue to be elevated. Smoking may be a form of self-medication in people with ADHD, which has specific reinforcing mechanisms such as improvement of ADHD core symptoms, enhancement of moods and arousal, or a combination of both. In addition, the reinforcing effects of smoking may be potentiated by stimulant medication.

The study examined the reinforcing effects of ad libitum smoking with and without ADHD medication in adult smokers with clinically diagnosed ADHD. Participants were adults with ADHD. The effects of two day of ADHD medication compared to two days on placebo for were studied on nicotine intake (i.e., cotinine levels). In addition, task performance on the Continuous Performance Task and nicotine withdrawal symptoms were examined in response to ADHD medication + smoking a cigarette versus ADHD medication + abstinence versus placebo medication + smoking versus placebo medication + abstinence.

The study identified the reinforcing mechanisms of smoking in interaction with ADHD medication. The findings will contribute to a better understanding of nicotine addiction and facilitate the development of targeted smoking cessation and prevention programs for individuals with ADHD and other people with deficiencies in impulse control and excessive risk taking.

Recruitment & Eligibility

Inclusion Criteria

Exclusion Criteria

Treatment for any major medical illness such as cancer, heart disease, diabetes, skin diseases, current major depressive episode, and schizophrenia even if currently controlled by medication
Current pregnancy, as measured by a pregnancy test (Clear Blue Easy, Unipath, Bedford, UK), or planning to become pregnant within the next 6 months. These individuals will not be included because smoking may cause harm to the unborn fetus
Nursing mothers
Non-English speaking people, because the majority of measurements used in the study have not been validated in languages other than English

Arm && Interventions

Group	Intervention	Description
ADHD medication versus placebo	ADHD medication	For the ADHD medication condition, participants received their usual dosage of their usual ADHD medication (e.g., Dextroamphetamine; Amphetamine mixed salts; Atomoxetine; O-Methylphenidate; Lisdexamfetamine). For the placebo condition, a placebo pill was administered.
ADHD medication versus placebo	Placebo	For the ADHD medication condition, participants received their usual dosage of their usual ADHD medication (e.g., Dextroamphetamine; Amphetamine mixed salts; Atomoxetine; O-Methylphenidate; Lisdexamfetamine). For the placebo condition, a placebo pill was administered.

Primary Outcome Measures

Name	Time	Method
The Effects of ADHD Medication Versus Placebo on Cotinine Levels	4 days	Salivary cotinine was measured across two days on ADHD medication versus two days on placebo.

Secondary Outcome Measures

Name	Time	Method
The Interacting Effects of Smoking and Overnight Abstinence With ADHD Medication and Placebo on Continuous Performance Task (CPT) Errors of Omission.	4 days	In the morning of each monitoring day, approximately 60 minutes after medication or placebo pill administration, participants were asked to either abstain from smoking or smoke their first cigarette of the day 5 minutes prior to starting the CPT.
The Interacting Effects of Smoking and Abstinence With ADHD Medication and Placebo on Nicotine Withdrawal Measured by the Shiffman-Jarvik Withdrawal Questionnaire.	4 days	The Shiffman-Jarvik withdrawal questionnaire measures nicotine withdrawal and was completed after each CPT assessment. The questionnaire consists of 25 items using 8-point scales. Total scores range from 0 to 200 and higher scores reflect higher levels of nicotine withdrawal.