Evaluating Motivation and Reward Mechanisms and Brain Substrates in Adults With Obesity

NCT03939676 | Completed

• 1 other identifier: Pro00032575
• Study Type: observational
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

Anhedonia and abnormalities in reward behavior are core features of overweight/obesity (OW), a highly prevalent condition within MDD populations, and is independently associated with reward disturbances. The investigators therefore aim to investigate the brain substrates subserving reward and motivation in adults with overweight/obesity. The primary aim of this pilot study is to determine whether associations exist between obesity and decreased performance on the respective motivation/reward paradigms.

Conditions

Anhedonia; Obesity

Outcome Measures

Primary Outcomes (3)

• Effort Expenditure for Rewards Task (EEfRT)

  The EEfRT task is a behavioural paradigm that is used to investigate the subject's effort-based decision-making. Subjects are presented with a series of repeated trials wherein they must choose between performing a hard task or an easy task in order to receive monetary compensation (subject's will receive greater compensation for completing the hard task and less compensation for completing the easy task). By presenting the subject with different probability levels for reward receipt, the objective is to examine the extent to which the relationship between motivation (i.e., anhedonia) and effort-based decision-making is modulated by perceived reward magnitude.

  1 day

• Monetary Incentive Delay (MID) Task

  The MID is a behavioural paradigm that assesses the basis of anticipation and consumption of reward and punishment. Each run of the MID task consists of approximately 72 trials. The types of cues presented include: circles (indicating the potential to win money i.e., gain cue), squares (indicating the potential to lose money i.e., loss cue), and a triangle (indicating no money will be won or lost i.e., neutral cue). A cue is presented for 500 ms, followed by a fixation cross (2,000 to 2,500 ms) and then the target square (160 to 260 ms), during which the participant is instructed to press a button as quickly as possible to win or avoid losing money. A feedback screen (1,650 ms), in which the top number indicates the amount of money won or lost during that trial, and the bottom number indicates the participant's total amount, is presented at the end of each trial.

  1 day

• Probablistic Reward Task (PRT)

  The PRT is a behavioural paradigm that measures response bias and sensitivity to reward under variable conditions. In this task, a signal detection approach is used, whereby subjects must discriminate between two non-ambiguous stimuli displayed rapidly on a computer screen in order to receive a monetary reward. Unbeknownst to the subjects, correct identification of one stimulus is reinforced three times more frequently than the other stimulus. Under these experimental circumstances, healthy subjects reliably develop a response bias for the stimulus that is reinforced more frequently, regardless of which stimulus was actually presented. Thus, reward responsiveness assessed in this task reflects the rapid shaping of future behavioral choices based on prior reinforcement experiences.

  1 day

Secondary Outcomes (1)

• MRI/DTI

  1 day

Study Arms (1)

Major Depressive Disorder or Bipolar Disorder

All eligible participants will be included in this single study arm.

Eligibility Criteria

• Age: 18 Years - 65 Years
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Participants will be identified at the Brain and Cognition Discovery Foundation (BCDF). Twenty subjects between the ages of 18-65 years with obesity, will be enrolled. All patients will be assessed for concurrent psychiatric disorders (e.g. mood disorders) and will meet DSM-V criteria for either: major depressive disorder (symptomatic or asymptomatic in any phase of the illness) or bipolar disorder I/II (symptomatic or asymptomatic in any phase of the illness).

You may qualify if:

• years of age
• Meeting DSM-V criteria for: (i) Major depressive disorder (symptomatic or asymptomatic in any phase of the illness) or (ii) bipolar disorder I/II (symptomatic or asymptomatic in any phase of the illness)
• Ability to provide written and informed consent
• Obesity 30 kg/m2
• Weight under 440lbs
• Shoulder-to-shoulder width under 60 cm

You may not qualify if:

• Age below 18 or above 65
• Use of benzodiazepines or consumption of alcohol within 12 hours of assessments
• Abuse of marijuana
• Physical, cognitive, or language impairments sufficient to adversely affect data derived from assessments
• Diagnosed reading disability or dyslexia
• Clinically significant learning disorder by history
• History of moderate or severe traumatic brain injury
• Other neurological disorders, or unstable systemic medical diseases
• Pregnancy and post-partum period
• Presence of any contra-indications for MRI
• Weight above 440lbs
• Shoulder-to-shoulder width greater than 60 cm.
• All subjects will be consented prior to initiating the study; \>45 BMI; suicidality as determined by clinical discretion

Sponsors & Collaborators

• Brain and Cognition Discovery Foundation: lead

Study Sites (1)

Canadian Rapid Treatment Centre of Excellence

Mississauga, Ontario, L5C 4E7, Canada

Location

MeSH Terms

Conditions

Anhedonia; Obesity

Condition Hierarchy (Ancestors)

Neurobehavioral Manifestations; Neurologic Manifestations; Nervous System Diseases; Signs and Symptoms; Pathological Conditions, Signs and Symptoms; Overweight; Overnutrition; Nutrition Disorders; Nutritional and Metabolic Diseases; Body Weight

Study Design

• Study Type: observational
• Observational Model: OTHER
• Time Perspective: CROSS SECTIONAL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Executive Director

Study Record Dates

• First Submitted: April 25, 2019
• First Posted: May 7, 2019
• Study Start: October 30, 2019
• Primary Completion: December 15, 2020
• Study Completion: December 15, 2020
• Last Updated: July 29, 2021

Record last verified: 2021-07

Data Sharing

• IPD Sharing: Will not share

Locations

CA (1)