The University of British Columbia study finds siblings of problem gamblers also impulsive and prone to risk-taking
9 October 2019
Biological siblings of people with gambling disorder also display markers of increased likelihood of impulsive behaviour and risk-taking, according to a new The University of British Columbia (UBC) psychology study.
The findings, published in Neuropsychopharmacology, suggest people with gambling disorder – a psychiatric term for serious gambling problems – may have pre-existing genetic vulnerabilities to the illness.
This study is the first to investigate vulnerabilities to gambling disorder by looking at siblings. The disorder, which is associated with severe negative consequences including depression, bankruptcy and family breakup, affects up to three per-cent of the Canadian population.
"Impulse behaviour, risky decision-making and altered brain reward processing are observed in people with gambling disorder," said lead author Eve Limbrick-Oldfield, a postdoctoral research fellow at the UBC department of psychology and Centre for Gambling Research. She added: "We wanted to find out whether these markers represent pre-existing vulnerabilities or are a consequence of how gambling changes the brain. To test this, we studied gamblers' siblings since they share similar genetic material and environment."
The researchers worked with 20 people with gambling disorder, 16 siblings and a control group of healthy volunteers. The participants were asked to complete questionnaires and cognitive computer tests that measured their level of impulsiveness and risk-taking behaviour. They also underwent brain scanning in an MRI while playing a slot machine task, to measure brain responses to rewards and wins.
The researchers found that both the problem gamblers and the siblings reported increased risk-taking and impulsivity compared to the control group. For example, problem gamblers and their siblings were more likely to act impulsively when experiencing negative emotions, and placed larger bets when making a risky choice.
Interestingly, the siblings showed no alterations in the brain response to rewards compared to the control group, leaving the possibility that the brain activity found in problem gamblers may have developed as a result of gambling experience.
The researchers note that siblings of problem gamblers were particularly difficult to recruit for the study because family relationships are often strained as a consequence of gambling problems.
"Since our study had a relatively small sample size, we hope it will encourage other researchers to replicate it so we could learn more about how genetics play a role in the gambling disorder," said study co-author Dr. Henrietta Bowden-Jones, director of the United Kingdom’s National Problem Gambling Clinic, from where the group with gambling disorder were recruited.
Bowden-Jones said the findings also highlight the potential for public awareness and gambling prevention.
“This research on the similarities in decision making between people suffering with gambling disorder and their siblings is a landmark study.
“We at the National Problem Gambling Clinic and UBC are grateful to all our patients and their siblings who took part.
“The results are of relevance in pointing towards pre-existing neurobiological vulnerabilities that predate the excessive gambling behaviours. This in turn gives us a better understanding of the origins of Gambling Disorder as well as of the importance of the role of genetics in addiction.”
The study, funded in part by the Medical Research Council and conducted at the National Problem Gambling Clinic in the U.K. (Central North West London NHS Foundation Trust). Brain scanning was carried out at Imperial College London. The Centre for Gambling Research at UBC is funded by the British Columbia government and the British Columbia Lottery Corporation.