Smoking, Withdrawal Nicotine, ADHD
Conditions
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.
Interventions
BEHAVIORALCigarette smoking
Participants had an fMRI scan during an experimental task consisting of mathematical problems after smoking a cigarette.
BEHAVIORALAbstinence
Participants had an fMRI scan during an experimental task consisting of mathematical problems after smoking abstinence.
Sponsors
National Institute on Drug Abuse (NIDA)
University of California, Irvine
Eligibility
Sex/Gender
ALL
Age
18 Years to 45 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Brain Activity | One 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
| Measure | Time frame | Description |
|---|---|---|
| DRD4 Genotype | one time blood draw | — |
| Salivary Cotinine | Once per week for 4 weeks | Average level of salivary cotinine over all time points (microgram/milliliter) |
Countries
United States
Participant flow
Recruitment details
Smokers and nonsmokers with and without ADHD
Participants by arm
| Arm | Count |
|---|---|
| ADHD Smokers ADHD smokers participated in two conditions: (1) after smoking a cigarette and (2) after overnight abstinence. | 19 |
| ADHD Nonsmokers ADHD nonsmokers participated in the abstinence condition. | 21 |
| Control Smokers Control smokers participated in two conditions: (1) after smoking a cigarette and (2) after overnight abstinence. | 23 |
| Control Nonsmokers Control nonsmokers participated in the abstinence condition. | 26 |
| Total | 89 |
Baseline characteristics
| Characteristic | ADHD Smokers | ADHD Nonsmokers | Control Smokers | Control Nonsmokers | Total |
|---|---|---|---|---|---|
| Age, Continuous | 23.00 years STANDARD_DEVIATION 1.7 | 27.24 years STANDARD_DEVIATION 7.96 | 25.04 years STANDARD_DEVIATION 4.29 | 22.69 years STANDARD_DEVIATION 1.85 | 24.44 years STANDARD_DEVIATION 4.88 |
| Gender Female | 2 Participants | 6 Participants | 4 Participants | 18 Participants | 30 Participants |
| Gender Male | 17 Participants | 15 Participants | 19 Participants | 8 Participants | 59 Participants |
| Region of Enrollment United States | 19 Participants | 21 Participants | 23 Participants | 26 Participants | 89 Participants |
Adverse events
| Event type | EG000 affected / at risk | EG001 affected / at risk | EG002 affected / at risk | EG003 affected / at risk |
|---|---|---|---|---|
| deaths Total, all-cause mortality | — / — | — / — | — / — | — / — |
| other Total, other adverse events | 0 / 19 | 0 / 21 | 0 / 23 | 0 / 26 |
| serious Total, serious adverse events | 0 / 19 | 0 / 21 | 0 / 23 | 0 / 26 |
Outcome results
Primary
Brain Activity
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.
Time frame: One MRI session for nonsmokers and two MRI sessions for smokers
Population: Discrepancies between participant flow and number of participants analyzed are due to motion artifacts, which compromised the MRI findings. Thus, a number of participants had to be excluded from the MRI data analysis.
| Arm | Measure | Group | Value (MEAN) | Dispersion |
|---|---|---|---|---|
| Smokers With ADHD After Abstinence | Brain Activity | BOLD Frontal Lobe | 2.08 z-score | Standard Deviation 0.23 |
| Smokers With ADHD After Abstinence | Brain Activity | BOLD Parietal Lobe | 2.69 z-score | Standard Deviation 0.53 |
| Smokers With ADHD After Abstinence | Brain Activity | BOLD Occipital Lobe | 2.72 z-score | Standard Deviation 0.47 |
| Nonsmokers With ADHD | Brain Activity | BOLD Frontal Lobe | 2.01 z-score | Standard Deviation 0.63 |
| Nonsmokers With ADHD | Brain Activity | BOLD Parietal Lobe | 2.30 z-score | Standard Deviation 0.37 |
| Nonsmokers With ADHD | Brain Activity | BOLD Occipital Lobe | 2.87 z-score | Standard Deviation 0.74 |
| Control Smokers After Abstinence | Brain Activity | BOLD Occipital Lobe | 2.71 z-score | Standard Deviation 0.61 |
| Control Smokers After Abstinence | Brain Activity | BOLD Frontal Lobe | 2.24 z-score | Standard Deviation 0.18 |
| Control Smokers After Abstinence | Brain Activity | BOLD Parietal Lobe | 2.48 z-score | Standard Deviation 0.37 |
| Control Nonsmokers | Brain Activity | BOLD Parietal Lobe | 2.77 z-score | Standard Deviation 0.71 |
| Control Nonsmokers | Brain Activity | BOLD Frontal Lobe | 2.30 z-score | Standard Deviation 0.2 |
| Control Nonsmokers | Brain Activity | BOLD Occipital Lobe | 2.88 z-score | Standard Deviation 0.49 |
| Smokers With ADHD After Smoking | Brain Activity | BOLD Frontal Lobe | 2.19 z-score | Standard Deviation 0.25 |
| Smokers With ADHD After Smoking | Brain Activity | BOLD Parietal Lobe | 2.61 z-score | Standard Deviation 0.72 |
| Smokers With ADHD After Smoking | Brain Activity | BOLD Occipital Lobe | 2.80 z-score | Standard Deviation 0.75 |
| Control Smokers After Smoking | Brain Activity | BOLD Parietal Lobe | 2.60 z-score | Standard Deviation 0.7 |
| Control Smokers After Smoking | Brain Activity | BOLD Occipital Lobe | 2.90 z-score | Standard Deviation 0.8 |
| Control Smokers After Smoking | Brain Activity | BOLD Frontal Lobe | 2.26 z-score | Standard Deviation 0.23 |
Comparison: Frontal BOLD during abstinence in smokers and nonsmokersp-value: 0.46ANOVA
Comparison: Parietal BOLD during abstinence in smokers and nonsmokersp-value: 0.012ANOVA
Comparison: Occipital BOLD during abstinence in smokers and nonsmokers.p-value: 0.04ANOVA
Comparison: Frontal BOLD smoking versus nonsmoking in smokers with ADHD compared to control smokers.p-value: 0.22ANOVA
Comparison: Parietal BOLD smoking versus nonsmoking in smokers with ADHD compared to control smokers.p-value: 0.51ANOVA
Comparison: Occipital BOLD smoking versus nonsmoking in smokers with ADHD compared to control smokers.p-value: 0.69ANOVA
Secondary
DRD4 Genotype
Time frame: one time blood draw
Population: Discrepancies between participant flow and data analyze reflect that not all participants provided blood samples. Dopamine genotypes were only available for participants who were also enrolled in the Multimodal Treatment for ADHD Study (MTA-Study).
| Arm | Measure | Group | Value (COUNT_OF_PARTICIPANTS) |
|---|---|---|---|
| Smokers With ADHD After Abstinence | DRD4 Genotype | DRD4-4R/7R | 1 Participants |
| Smokers With ADHD After Abstinence | DRD4 Genotype | DRD4-4R/4R | 5 Participants |
| Smokers With ADHD After Abstinence | DRD4 Genotype | DRD4-3R/4R | 1 Participants |
| Smokers With ADHD After Abstinence | DRD4 Genotype | DRD4-3R/3R | 1 Participants |
| Smokers With ADHD After Abstinence | DRD4 Genotype | DRD4-2R/4R | 2 Participants |
| Smokers With ADHD After Abstinence | DRD4 Genotype | DRD4-2R/2R | 0 Participants |
| Nonsmokers With ADHD | DRD4 Genotype | DRD4-2R/2R | 1 Participants |
| Nonsmokers With ADHD | DRD4 Genotype | DRD4-3R/3R | 0 Participants |
| Nonsmokers With ADHD | DRD4 Genotype | DRD4-4R/7R | 5 Participants |
| Nonsmokers With ADHD | DRD4 Genotype | DRD4-3R/4R | 0 Participants |
| Nonsmokers With ADHD | DRD4 Genotype | DRD4-4R/4R | 1 Participants |
| Nonsmokers With ADHD | DRD4 Genotype | DRD4-2R/4R | 0 Participants |
| Control Smokers After Abstinence | DRD4 Genotype | DRD4-4R/4R | 3 Participants |
| Control Smokers After Abstinence | DRD4 Genotype | DRD4-3R/4R | 0 Participants |
| Control Smokers After Abstinence | DRD4 Genotype | DRD4-3R/3R | 0 Participants |
| Control Smokers After Abstinence | DRD4 Genotype | DRD4-2R/2R | 0 Participants |
| Control Smokers After Abstinence | DRD4 Genotype | DRD4-2R/4R | 0 Participants |
| Control Smokers After Abstinence | DRD4 Genotype | DRD4-4R/7R | 2 Participants |
| Control Nonsmokers | DRD4 Genotype | DRD4-2R/4R | 1 Participants |
| Control Nonsmokers | DRD4 Genotype | DRD4-2R/2R | 0 Participants |
| Control Nonsmokers | DRD4 Genotype | DRD4-4R/4R | 7 Participants |
| Control Nonsmokers | DRD4 Genotype | DRD4-3R/3R | 0 Participants |
| Control Nonsmokers | DRD4 Genotype | DRD4-4R/7R | 10 Participants |
| Control Nonsmokers | DRD4 Genotype | DRD4-3R/4R | 0 Participants |
Secondary
Salivary Cotinine
Average level of salivary cotinine over all time points (microgram/milliliter)
Time frame: Once per week for 4 weeks
Population: Discrepancies between participants cotinine samples and participant flow are due to the fact that not all participants provided useful saliva samples.
| Arm | Measure | Value (MEAN) | Dispersion |
|---|---|---|---|
| Smokers With ADHD After Abstinence | Salivary Cotinine | 100.06 Microgram/milliliter | Standard Deviation 111.52 |
| Nonsmokers With ADHD | Salivary Cotinine | 24.53 Microgram/milliliter | Standard Deviation 86.66 |
| Control Smokers After Abstinence | Salivary Cotinine | 104.99 Microgram/milliliter | Standard Deviation 84.75 |
| Control Nonsmokers | Salivary Cotinine | 23.13 Microgram/milliliter | Standard Deviation 52.65 |