Cigarette Smoking in Smokers With and Without Schizophrenia

Cigarette Smoking in Smokers With and Without a Diagnosis of Schizophrenia

Higher rates and severity of tobacco dependence in people with schizophrenia, as compared with the general population, contribute to the lower life expectancy seen in this population. Dependent tobacco smoking is controlled by how different aspects of cigarette smoking are perceived. There is evidence suggesting that people with schizophrenia differ in how they perceive cigarette smoking, which, if confirmed, would have implications for tailoring treatment interventions for smoking cessation in schizophrenia.

Study Overview

• Status: Completed
• Conditions: Schizophrenia; Tobacco Dependence
• Intervention / Treatment: Combination product: Sampling Research Cigarettes

Detailed Description

The aim of the present study is to determine whether tobacco smoking in people with schizophrenia is governed by different aspects and effects of cigarette consumption. Smokers participating in this study either have no psychiatric diagnosis, or a diagnosis of schizophrenia or schizoaffective disorder. Over four study visits, participants will sample and compare different research cigarettes, complete questionnaires and concentration tasks, and smoke one type of research cigarette for eight hours while wearing a nicotine patch. By shaping our understanding of tobacco dependence in schizophrenia, the present project may redirect treatment development toward strategies tailored to the specific vulnerabilities of this population, which is among the most severely affected by its detrimental impact on health and life.

• Study Type: Interventional
• Enrollment (Actual): 31
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Maryland
    • Catonsville, Maryland, United States, 21228
      • Maryland Psychiatric Research Center

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 60 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Regular smoker of at least 10 cigarettes or cigarillos/day for at least 2 years
• For participants with schizophrenia: DSM-5 diagnosis of schizophrenia or schizoaffective disorder
• For participants with schizophrenia: Able to give informed consent
• For smokers with schizophrenia: No change in psychiatric medication or dosage in the last 4 weeks

Exclusion Criteria:

• Uncontrolled hypertension (resting systolic BP above 150 or diastolic above 95 mm Hg)
• Cardiovascular disease, such as history of myocardial infarction and ischemia, heart failure, angina, severe arrhythmias, or EKG abnormalities
• Severe asthma
• Chronic obstructive pulmonary disease
• Neurological illness, such as stroke, seizure disorder, neurodegenerative disease, or organic brain syndrome
• Mental retardation
• Alcohol or substance use disorder except nicotine within the last year
• Use of benztropine (Cogentin), varenicline (Chantix), bupropion (Wellbutrin, Zyban), or any type of nicotine replacement
• Pregnant or lactating
• For healthy control smokers: DSM-5 diagnosis of depression, bipolar disorder, ADHD, autism spectrum disorder, anorexia, bulimia nervosa, or any schizophrenia-spectrum disorder
• For healthy control smokers: immediate family history of psychosis

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Other: Smokers with schizophrenia; This is a diagnostic group, defined independently from this study.	Combination product: Sampling Research Cigarettes; Participants sample two research cigarettes, which differ in typical tobacco smoke constituents such as tar, nicotine, carbon monoxide, etc. In the Cigarette Discrimination Session, participants sample both types of cigarettes repeatedly, guess their identity (A or B) with regard to reference cigarettes, and rate their subjective effects. In the Ad Libitum Smoking Session, participants can smoke one of these cigarette types as much or as little as they like for eight hours.
Other: Smokers without schizophrenia; This is a diagnostic group (i.e., no diagnosis of schizophrenia), defined independently from this study.	Combination product: Sampling Research Cigarettes; Participants sample two research cigarettes, which differ in typical tobacco smoke constituents such as tar, nicotine, carbon monoxide, etc. In the Cigarette Discrimination Session, participants sample both types of cigarettes repeatedly, guess their identity (A or B) with regard to reference cigarettes, and rate their subjective effects. In the Ad Libitum Smoking Session, participants can smoke one of these cigarette types as much or as little as they like for eight hours.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Cigarette Discrimination Accuracy	Participants sample 4 cigarettes of type A and 4 cigarettes of type B in a double-blind manner and indicate for each cigarette if they think it is of type A or B. Two reference trials with cigarette type unblinded will be performed before the first and fifth sample cigarette. For each sampled cigarette, the score is either 1 (correct) or 0 (incorrect). Discrimination accuracy is calculated by averaging the eight scores for each participant.	One day (in the Cigarette Discrimination Session), over a 6-hour time frame.
End-of-session Carbon Monoxide	The concentration (ppm) of carbon monoxide (CO) in breath is measured by exhalation into a CO breathalyzer at the end of the 8-hour Ad Libitum Smoking Session. Only very-low-nicotine-content (virtually nicotine-free) cigarettes were consumed in this session.	One day (in the Ad Libitum Smoking Session), over an 8-hour time frame.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in the Number of Research Cigarettes Smoked	In the Ad Libitum Smoking Session, participants can smoke as many research cigarettes (all very-low-nicotine-content) as they wish. The propensity to maintain smoking despite the absence of nicotine was quantified by subtracting the number of cigarettes smoked in the last two hours from that in the first two hours of the session. Smaller difference values indicate that smoking was upheld by very-low-nicotine-content cigarettes.	One day (in the Ad Libitum Smoking Session), over an 8-hour time frame.
Difference in Subjective State Composite Score	The measure is derived by transforming scores on the Minnesota Nicotine Withdrawal Scale (where higher values signify more withdrawal), the Affect-based Withdrawal Scale (higher values signify a worse emotional state), Questionnaire for Smoking Urges (higher values indicate more craving), and modified Cigarette Evaluation Questionnaire (mCEQ, higher values indicate greater subjective effects of smoking on mood, hunger, physiology) into standard z-scores, thus giving each scale a mean of 0 and standard deviation of 1. Withdrawal and craving scores were re-poled (inversing the sign), and scales were averaged for each subject. The resulting composite quantified the subjective state response to cigarette smoking, larger values indicating less withdrawal, less craving, and larger effects on the mCEQ. The difference therein between the research cigarettes containing nicotine and those containing almost no nicotine quantified the subjective state response to nicotine.	One day (in the Cigarette Discrimination Session), over a 6-hour time frame.

Collaborators and Investigators

• Sponsor: University of Maryland, Baltimore
• Investigators: Principal Investigator: Britta Hahn, Ph.D., University of Maryland, Baltimore

Study record dates

Study Major Dates

• Study Start (Actual): July 15, 2021
• Primary Completion (Actual): December 23, 2022
• Study Completion (Actual): December 23, 2022

Study Registration Dates

• First Submitted: June 24, 2019
• First Submitted That Met QC Criteria: June 26, 2019
• First Posted (Actual): June 27, 2019

Study Record Updates

• Last Update Posted (Actual): September 26, 2024
• Last Update Submitted That Met QC Criteria: June 6, 2024
• Last Verified: June 1, 2024

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Mental Disorders; Chemically-Induced Disorders; Substance-Related Disorders; Schizophrenia Spectrum and Other Psychotic Disorders; Schizophrenia; Tobacco Use Disorder
• Other Study ID Numbers: HP-00086422

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: No
• Studies a U.S. FDA-regulated device product: No