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Association Between Smoking, Brain Activity, Genes, and ADHD

Completed
Conditions
Withdrawal Nicotine
Smoking
ADHD
Interventions
Behavioral: Cigarette smoking
Behavioral: Abstinence
Registration Number
NCT00915798
Lead Sponsor
University of California, Irvine
Brief Summary

The study investigated the underlying mechanisms of smoking in young adults by examining the associations between smoking, brain activity, dopamine genes, and attention deficit hyperactivity disorder (ADHD).

Detailed Description

The study investigated the underlying mechanisms of smoking in young adults by examining the associations between smoking, brain activity, dopamine genes, and attention deficit hyperactivity disorder (ADHD). Four groups of young adults were recruited: (1) smokers with ADHD; (2) nonsmokers with ADHD; (3) normative control smokers; and (4) normative control nonsmokers. Smoking was assessed via questionnaires and salivary cotinine levels. Brain activity was examined via functional Magnetic Resonance Imaging (fMRI). Each nonsmoker underwent an fMRI scan during an experimental task consisting of mathematical problems. Smokers underwent two fMRI scans during similar experimental tasks under the following two conditions: (1) after smoking a cigarette and (2) after overnight abstinence. The association between the DRD4-7 repeat allele and smoking was explored.

Recruitment & Eligibility

Status
COMPLETED
Sex
All
Target Recruitment
89
Inclusion Criteria
  1. Smokers with ADHD

    • Cigarette smoking for the last year
    • ADHD diagnosis
  2. Nonsmokers with ADHD

    • No history of regularly smoking cigarettes
    • ADHD diagnosis
  3. Normative control smokers

    • Cigarette smoking for the last year
    • No history and diagnosis of ADHD
  4. Normative control nonsmokers

    • No history of regularly smoking cigarettes
    • No history and diagnosis of ADHD
Exclusion Criteria
  • Children under the age of 18
  • Adults above the age of 45
  • Pregnancy or planning to become pregnant
  • Any major medical illness
  • Any mental disorders that require medication (except stimulant medication)
  • Any contraindications to fMRI scanning
  • Not speaking English

Study & Design

Study Type
OBSERVATIONAL
Study Design
Not specified
Arm && Interventions
GroupInterventionDescription
Smokers with ADHDCigarette smokingSmokers with ADHD participated in one overnight abstinence condition (withdrawal) and one smoking condition (smoking the first cigarette of the morning).
Nonsmokers with ADHDAbstinenceNonsmokers with ADHD participated in one condition.
Control smokersAbstinenceControl smokers participated in one overnight abstinence condition (withdrawal) and one smoking condition (smoking the first cigarette of the morning).
Smokers with ADHDAbstinenceSmokers with ADHD participated in one overnight abstinence condition (withdrawal) and one smoking condition (smoking the first cigarette of the morning).
Control smokersCigarette smokingControl smokers participated in one overnight abstinence condition (withdrawal) and one smoking condition (smoking the first cigarette of the morning).
Control nonsmokersAbstinenceControl nonsmokers participated in one condition.
Primary Outcome Measures
NameTimeMethod
Brain ActivityOne MRI session for nonsmokers and two MRI sessions for smokers

BOLD z-score of smokers with ADHD after abstinence/smoking a cigarette, control smokers after abstinence/smoking a cigarette, nonsmokers with ADHD, and control nonsmokers. All participants performed a mathematical task in the MRI scanner. Higher BOLD z-scores indicate greater brain activation.

Secondary Outcome Measures
NameTimeMethod
DRD4 Genotypeone time blood draw
Salivary CotinineOnce per week for 4 weeks

Average level of salivary cotinine over all time points (microgram/milliliter)

Trial Locations

Locations (1)

2500 Red Hill Avenue

🇺🇸

Santa Ana, California, United States

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