Sex Differences in the Response to Abstinence From Alcohol. (SPAR)

May 12, 2026 updated by: Martin Plawecki, Indiana University
In laboratory animals, repeated cycles of abstinence from and return to alcohol drinking can lead to changes in alcohol intake. In a study of the effect of abstinence on drinking in humans, the investigators found evidence that abstinence affects drinking differently in women compared to men. In the present study, the investigators propose to study how men and women respond to abstinence, and whether this information can be used to improve intervention and prevention strategies.

Study Overview

Detailed Description

Women and men differ in how quickly they progress from social to problematic alcohol drinking. In laboratory animals, short-term abstinence increases alcohol consumption, with repeated deprivations leading to disordered drinking. In a preliminary study, the investigators found that men and women differed in how their motivation to drink alcohol changed after a short period of abstinence. The investigators hypothesize that this difference may affect their transition to alcohol use disorders. The objectives of this application are to characterize the human post abstinence response, and use identical alcohol exposures to study the mechanisms underlying identified sex differences. In addition, the investigators will complete a 2 year prospective study of natural drinking patterns to assess how self-reported abstinence intervals influence drinking trajectories. The long-term goal of this project is to inform alcohol use disorder treatment and to design and test novel interventions using the laboratory model of post-abstinence response. There is a critical unfilled need to understand sex differences in disease progression, and this lab-based assessment coupled to longitudinal follow-up provides the rigorous experimental design to begin to meet that need. This project will increase scientific knowledge by advancing the translation between preclinical and clinical models, eventually informing sex-specific intervention and prevention strategies for problematic drinking and establishing a model to test those interventions..

Study Type

Interventional

Enrollment (Estimated)

160

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 Contact

Study Locations

    • Indiana
      • Indianapolis, Indiana, United States, 46202
        • Recruiting
        • University Hospital
        • Contact:
        • Principal Investigator:
          • Martin H Plawecki, MD, PhD
        • Principal Investigator:
          • Melissa A Cyders, PhD
        • Sub-Investigator:
          • Wei Wu, PhD

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

21 years to 35 years (Adult)

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Moderate social drinkers
  • Able to understand/complete questionnaires and procedures in English
  • Body mass index (BMI) between 18.5 and 32 kg/m2
  • Have venous access sufficient to allow blood sampling

Exclusion Criteria:

  • Pregnant or breast-feeding women, or women who intend to become pregnant
  • Do not attest to using accepted forms of birth control for the infusion phase of the study
  • Current treatment for, or desire to be treated for, any substance use disorder or court ordered to not drink alcohol
  • History of significant adverse reaction to alcohol
  • Medical disorders or other conditions such as alcohol withdrawal seizures or delirium tremens that may influence study outcome or participant safety
  • Medications (past 30 days) that could influence data or participant safety (e.g. antidepressants, antipsychotics, benzodiazepines, etc.) as determined by investigators
  • DSM 5 Disorders (non AUD) or current/history of neurological disease of cerebral origin, or head injury with > 20 min loss of consciousness
  • Positive breath alcohol reading on arrival at any study visit
  • Actively suicidal (for example, any suicide attempts within the past year or any current suicidal intent, including a plan) or are at serious suicidal risk, by clinical judgment of the investigator
  • Any condition for which the principal investigators determine it is unsafe or not prudent to enroll

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: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Free access alcohol self-administration
During the 2.5-hour free-access self-administration sessions, the participant may choose to complete a task for an alcohol or water reward. Interventions include Abstinence from Alcohol and Usual Drinking
Participants will undergo a laboratory alcohol infusion session that terminates 2 weeks of monitored abstinence from alcohol
Participants will undergo a laboratory alcohol infusion session during a period of usual drinking behavior
During the laboratory alcohol infusion sessions, alcohol is infused through an indwelling catheter.
Other Names:
  • 6.0& (v/V) ethanol solution
Experimental: Clamped alcohol exposure
A battery of behavioral tasks will be administered to participants before, and at the beginning and end of a 3 hour clamped exposure to alcohol (fixed at 80 mg/dL). EEG will be recorded throughout to assess event related potentials associated with task performance. Interventions include Abstinence from Alcohol and Usual Drinking.
Participants will undergo a laboratory alcohol infusion session that terminates 2 weeks of monitored abstinence from alcohol
Participants will undergo a laboratory alcohol infusion session during a period of usual drinking behavior
During the laboratory alcohol infusion sessions, alcohol is infused through an indwelling catheter.
Other Names:
  • 6.0& (v/V) ethanol solution

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Sex differences in the effect of abstinence on alcohol self-administration.
Time Frame: 2 single day laboratory sessions, one following 2 weeks alcohol abstinence
The effect of 2 weeks abstinence on intravenous alcohol intake will be compared in men and women.
2 single day laboratory sessions, one following 2 weeks alcohol abstinence
Sex differences in the effect of abstinence on sensitivity of the P3 response to alcohol.
Time Frame: 2 single day laboratory sessions, one following 2 weeks alcohol abstinence
The effect of 2 weeks abstinence from alcohol on sensitivity of the neurophysiological P3 response to alcohol, assessed using a stop-signal response task, will be compared in women and men during an iv infusion clamp.
2 single day laboratory sessions, one following 2 weeks alcohol abstinence
Sex differences in the effect of abstinence on subjective responses to alcohol.
Time Frame: 2 single day laboratory sessions, one following 2 weeks alcohol abstinence
The effect of 2 weeks abstinence from alcohol on subjective responses to alcohol in women and men will be assessed using a survey during an iv infusion clamp.
2 single day laboratory sessions, one following 2 weeks alcohol abstinence
The role of changes in alcohol elimination on sex differences in response to abstinence.
Time Frame: 2 single day laboratory sessions, one following 2 weeks alcohol abstinence
The effect of 2 weeks abstinence from alcohol on alcohol elimination in men and women will be assessed using an iv alcohol infusion clamp.
2 single day laboratory sessions, one following 2 weeks alcohol abstinence

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Response to abstinence as a predictor of alcohol risk in women and men.
Time Frame: 2 years
For both Arm 1 and Arm 2, daily alcohol consumption will be surveyed every 2 months for 2 years following the laboratory sessions. Self-imposed periods of abstinence will be assessed to determine if subsequent daily alcohol intake increases or decreases, and to determine if men and women differ in the effect of abstinence on drinking.
2 years

Collaborators and Investigators

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

Investigators

  • Principal Investigator: Martin H Plawecki, MD, PhD, Psychiatry, Indiana University School of Medicine
  • Principal Investigator: Melissa A Cyders, PhD, Psychology, Indiana University-Purdue University at Indianapolis

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)

April 10, 2019

Primary Completion (Estimated)

August 31, 2026

Study Completion (Estimated)

August 31, 2028

Study Registration Dates

First Submitted

November 12, 2018

First Submitted That Met QC Criteria

January 30, 2019

First Posted (Actual)

February 1, 2019

Study Record Updates

Last Update Posted (Actual)

May 15, 2026

Last Update Submitted That Met QC Criteria

May 12, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

IPD Plan Description

The final raw dataset will be available to other researchers when we have collected all subjects and completed our own planned analyses. Prior to completion of our own planned analyses, we would be willing to consider releasing the dataset upon request. We will work with our IRB to establish a strategy for de-identifying the data while retaining the ability to ensure the quality of the stored data, and develop a data-sharing agreement.

IPD Sharing Time Frame

After all subjects have been collected and the primary outcomes accepted for publication. The dataset will be available indefinitely,

IPD Sharing Access Criteria

On request to the PIs

IPD Sharing Supporting Information Type

  • STUDY_PROTOCOL
  • SAP
  • ICF

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.

No

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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