Investigation of Nicotine Seeking Behavior in Current Smokers (NSS)

September 12, 2018 updated by: Eric Andrew Woodcock, Wayne State University

Neuropharmacological Investigation of Frontostriatal Network Function and Nicotine Seeking Behavior in Current Smokers

In this study, 21 non-treatment-seeking cigarette smokers were recruited to investigate the effects of acute stress on brain function and nicotine seeking/self-administration behavior.

Study Overview

Detailed Description

Non-treatment-seeking cigarette smoking individuals were recruited from the Detroit, MI area. Individuals were screened for cardiovascular, neurological, and psychiatric contraindications. 21 healthy smokers completed two oral pre-treatment experimental sessions (on separate non-consecutive days) in randomized order under double-blind conditions: placebo (lactose) and stress (54mg yohimbine and 10mg hydrocortisone). Yohimbine + hydrocortisone elicit a neurochemical and physiological response that mimics a 'natural' stressor. Placebo and stress sessions were identical and started at 11am. Upon arrival, subject sobriety was confirmed with expired breath alcohol measurement (<.02%). At 11:30am, each subject smoked 6 cigarette puffs (preferred brand; provided by study) over 5 minutes to control for recent nicotine exposure. Throughout each experimental session, subjects periodically completed self-reported measures of cigarette craving, nicotine withdrawal symptoms, affect, and anxiety, and vital signs were measured. Subjects self-administered (swallowed) oral doses of yohimbine (or placebo) at 11:45am and hydrocortisone (or placebo) at 12:15pm. At 1pm, subjects completed a 60-min neuroimaging scan which included: 1) T1-weighted structural scan, 2) proton functional magnetic resonance spectroscopy (fMRS) acquisition from the left prefrontal cortex during a letter 2-back working memory paradigm, and 3) functional magnetic resonance imaging (fMRI) acquisition during an N-back paradigm yoked with cigarette cues. At 2:30pm, subjects completed an 11-trial choice progressive ratio task in which they could earn cigarette puffs (preferred brand; provided by study) or money. At 3pm, subjects self-administered earned cigarette puffs (video monitored). Subjects remained on site until 4pm discharge.

Study Type

Interventional

Enrollment (Actual)

21

Phase

  • Phase 1

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

    • Michigan
      • Detroit, Michigan, United States, 48201
        • Wayne State University

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

19 years to 33 years (Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • 1) Aged between 21-35 years old, 2) current smokers (expired breath carbon monoxide > 4ppm, self-reported 10+ cigarettes/day, Fagerstrom test for nicotine dependence score > 3, 3) normal seated and resting vital signs (systolic blood pressure 80-160mmHg, diastolic blood pressure 50-90mmHg, and heart rate 50-90 bpm), and 4) normal or corrected-normal vision.

Exclusion Criteria:

  • 1) Abnormal electrocardiogram (reviewed by licensed cardiologist), 2) magnetic resonance imaging contraindications (e.g. metal implants), 3) medical/neurological contraindications (e.g., diabetes or head trauma), 4) pregnancy (urine test; females only), 5) positive urine test result for opioids, cocaine metabolites, benzodiazepines, barbiturates, or amphetamines, 6) psychiatric contraindications (subject met criteria for current Axis 1 disorder [other than nicotine dependence] as indicated by computerized MINI-6 screen), and 7) self-reported marijuana and/or alcohol use on 15+ days in the past month.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Basic Science
  • Allocation: Randomized
  • Interventional Model: Single Group Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Placebo
The placebo compound, Lactose Monohydrate Powder, was encapsulated in generic opaque capsules identical to the capsules used in the acute stress session. During the placebo session, two capsules were self-administered (swallowed) by each subject. At 11:45am, subjects self-administered a capsule containing 54mg of lactose. At 12:15pm, subjects self-administered a capsule containing 10mg of lactose.
Lactose powder was encapsulated in generic opaque capsules identical to those used during the acute stress session. Lactose doses weighed the same as the acute stress session doses (54mg and 10mg, respectively).
Other Names:
  • Placebo
Experimental: Acute Stress
During the acute stress experimental session, subjects self-administered two generic opaque capsules. At 11:45am, subjects self-administered a capsule containing 54mg of Yohimbine Hydrochloride powder. At 12:15pm, subjects self-administered a capsule containing 10mg of Hydrocortisone.
54mg of yohimbine powder was encapsulated in a generic opaque capsule and swallowed with water.
Other Names:
  • YOH
10mg hydrocortisone was encapsulated in a generic opaque capsule and swallowed with water.
Other Names:
  • HYD

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Cigarette puff vs. money choice task
Time Frame: 30 minutes
Participants could earn (via computer mouse 'clicks') money or cigarette puffs (preferred brand; provided by the study) across 11 independent choice trials. At the start of each trial, subjects selected either money or cigarette puffs on a computer screen. After each selection, subjects could earn one unit of that selection by satisfying the computer 'mouse' click requirement. The click requirement increased with each successive unit earned separately for cigarette puffs and money following a progressive ratio schedule (5, 12, 33, 100, 180, 340, 540, 835, 1220, 1660, and 2275 'mouse' clicks; identical schedule for both options and experimental sessions). Units were $0.25 money and 1 cigarette puff. Earned cigarette puffs were smoked at the end of the task and earned money was applied to the subject's study payment. The task was completed between 2:30pm and 3pm for each session.
30 minutes

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Letter 2-back task
Time Frame: 12 minutes
Participants completed 5 blocks of a letter 2-back working memory task during proton functional magnetic resonance spectroscopy data acquisition from the left dorsolateral prefrontal cortex. The 2-back task consisted of a neurochemistry normalization period (passive viewing of a 3Hz flashing checkerboard; 208s) and alternating periods of passive visual fixation (centered fixation cross; 32s) and letter 2-back (64s; 4s instructions ['2-back'], 20 letters [3s/letter; 500ms on screen; 2500ms blank screen], 6 target letters). Changes in neurochemistry as quantified using LCModel were the primary outcome variable. 2-back response accuracy (% correct) and response latency (ms) were secondary outcomes.
12 minutes
Cigarette-cued letter N-back task
Time Frame: 15 minutes
Participants completed a neutral image vs. cigarette smoking-related image cued letter N-back task during functional magnetic resonance imaging acquisition. The task consisted of pseudo-randomly ordered blocks of 0-, 1-, and 2-back with either cigarette cues or matched neutral images behind each letter. Two 32s blocks of each task permutation were collected separated by 16s of blank screen (to minimize carry-over effects). Patterns of brain activation throughout the task was the primary outcome measure while N-back response accuracy (% correct) and response latency (ms) were secondary outcomes.
15 minutes

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Minnesota Nicotine Withdrawal Scale
Time Frame: 1 minute; collected five times throughout each experimental session
Well-validated self-report measure of nicotine withdrawal symptoms was measured (MNWS; Hughes and Hatsukami, 1986). Subjects were asked to rate 15 adjectives describing common nicotine withdrawal symptoms on a 5-point Likert scale reflecting symptom severity during the past 10 minutes from 0='not present' to 4='severe'. Mean scores were calculated across items with higher values (maximum=4) reflecting greater withdrawal symptom severity and lower scores (minimum=0) reflecting less severe withdrawal symptoms.
1 minute; collected five times throughout each experimental session
Brief Questionnaire of Smoking Urges
Time Frame: 1 minute; collected five times throughout each experimental session
Well-validated self-report measure of subjective cigarette craving was measured (QSU; Cox et al., 2001). The self-report measure consists of 10-items with first-person statements describing one's desire to smoke a cigarette. Items are rated on a 7-point Likert scale: 1='strongly disagree' to 7='strongly agree'. Two sub-scales were considered separately; appetitive vs. relief-motivated craving. Sub-scales were quantified as a sum of items: higher scores reflected greater cigarette craving (both sub-scale scores range=5-35).
1 minute; collected five times throughout each experimental session
State-Trait Anxiety Inventory
Time Frame: 1 minute; collected five times throughout each experimental session
Well-validated self-report measure of state anxiety symptoms was measured (STAI; Spielberger, 1985). Subjects were asked to rate 20 first-person statements describing one's anxiety at this moment from 1='not at all' to 4='very much so'. State anxiety was quantified as a sum across items with higher scores reflecting more anxiety (range=20-80).
1 minute; collected five times throughout each experimental session
Positive-Negative Affect Scale
Time Frame: 1 minute; collected five times throughout each experimental session
Well-validated measure of self-reported positive and negative affect was measured (PANAS; Watson et al., 1988). Subjects were asked to rate 20 adjectives on a 5-point Likert scale from 1='not at all or very slightly' to 5='extremely'. Two sub-scales were analyzed separately: positive vs. negative affect. Mean scores for each sub-scale were calculated and ranged from 1 to 5 with higher scores reflecting more positive or more negative affect.
1 minute; collected five times throughout each experimental session
Blood pressure
Time Frame: 1 minute; collected six times throughout each experimental session
Seated and resting systolic and diastolic blood pressure (BP; mmHg) was measured.
1 minute; collected six times throughout each experimental session
Heart Rate
Time Frame: 1 minute; collected six times throughout each experimental session
Seated and resting heart rate (HR; bpm) was measured.
1 minute; collected six times throughout each experimental session

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Investigators

  • Principal Investigator: Eric A Woodcock, PhD, Wayne State University

Publications and helpful links

The person responsible for entering information about the study voluntarily provides these publications. These may be about anything related to the study.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

January 7, 2016

Primary Completion (Actual)

October 4, 2016

Study Completion (Actual)

October 4, 2016

Study Registration Dates

First Submitted

September 9, 2018

First Submitted That Met QC Criteria

September 12, 2018

First Posted (Actual)

September 13, 2018

Study Record Updates

Last Update Posted (Actual)

September 13, 2018

Last Update Submitted That Met QC Criteria

September 12, 2018

Last Verified

September 1, 2018

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

No

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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