Cigarette Smoking in Smokers With and Without Schizophrenia

NCT04001114 | Completed Results DMC

• 1 other identifier: HP-00086422
• Study Type: interventional
• Target: 31
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Tobacco Dependence; Schizophrenia

Outcome Measures

Primary Outcomes (2)

• 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.

• 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.

Secondary Outcomes (2)

• Change in the Number of Research Cigarettes Smoked

  One day (in the Ad Libitum Smoking Session), over an 8-hour time frame.

• Difference in Subjective State Composite Score

  One day (in the Cigarette Discrimination Session), over a 6-hour time frame.

Study Arms (2)

Smokers with schizophrenia

OTHER

This is a diagnostic group, defined independently from this study.

Combination Product: Sampling Research Cigarettes

Smokers without schizophrenia

OTHER

This is a diagnostic group (i.e., no diagnosis of schizophrenia), defined independently from this study.

Combination Product: Sampling Research Cigarettes

Interventions

Sampling Research Cigarettes COMBINATION_PRODUCT

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.

Smokers with schizophrenia; Smokers without schizophrenia

Eligibility Criteria

• Age: 18 Years - 60 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• 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

You may not qualify if:

• 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

Sponsors & Collaborators

• University of Maryland, Baltimore: lead

Study Sites (1)

Maryland Psychiatric Research Center

Catonsville, Maryland, 21228, United States

Location

MeSH Terms

Conditions

Tobacco Use Disorder; Schizophrenia

Condition Hierarchy (Ancestors)

Substance-Related Disorders; Chemically-Induced Disorders; Mental Disorders; Schizophrenia Spectrum and Other Psychotic Disorders

Limitations and Caveats

The targeted enrollment was not achieved, and sample sizes are smaller than necessary to assess all study predictions.

Results Point of Contact

• Title: Britta Hahn, Ph.D.
• Organization: University of Maryland

bhahn@som.umaryland.edu

410-402-6112

Study Officials

• Britta Hahn, Ph.D.

  University of Maryland, Baltimore

  PRINCIPAL INVESTIGATOR

Publication Agreements

• PI is Sponsor Employee: No
• Restrictive Agreement: No

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: NON RANDOMIZED
• Masking: DOUBLE
• Who Masked: PARTICIPANT, INVESTIGATOR
• Masking Details: Participants compare different research cigarettes. Neither the participant nor the investigators know which cigarette is of which type.
• Purpose: BASIC SCIENCE
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Associate Professor

Model Details: We will compare participants with and without a diagnosis of schizophrenia. Study procedures are identical for the two groups.

Study Record Dates

• First Submitted: June 24, 2019
• First Posted: June 27, 2019
• Study Start: July 15, 2021
• Primary Completion: December 23, 2022
• Study Completion: December 23, 2022
• Last Updated: September 26, 2024
• Results First Posted: September 26, 2024

Record last verified: 2024-06

Data Sharing

• IPD Sharing: Will not share

Locations

US (1)