ADHD News & Research

ADHD and Obesity Share a Genetic Link to Patients’ Propensity for Instant Gratification

Delay discounting — or the tendency to choose immediate rewards over future ones — shares genetic links with both ADHD and obesity, according to a large genetic survey.

<December 19, 2017

Would you rather be handed $100 right now — or get $200 next month?

According to a large new study, you are more likely to choose the former if you have ADHD or are obese. This research was the first to identify underlying genetic causes behind this preference for instant gratification, known as delay discounting.

To identify the genetic roots of delay discounting, researchers at the University of California, San Diego (UCSD) recruited more than 23,000 members of the genetic testing company 23andMe. Subjects answered a series of survey questions — for example, “Would you rather have $55 today or $75 in 61 Days?” — that assessed their tendency toward delay discounting. Results were then cross-referenced with subjects’ chromosomal markers.

The researchers found that approximately 12 percent of a subject’s variation in delay discounting could be linked to a specific range of genes. Those genes overlapped significantly with those linked to ADHD and obesity — as well as other related conditions like mood disorders, effect of nicotinism, and schizophrenia.

While the results may come as little surprise to those living with ADHD — particularly those with poor impulse control — understanding the genetic markers behind delay discounting is critical to managing behaviors that can have long-term consequences, the researchers said.

“A person’s ability to delay gratification is not just a curiosity,” said senior author Abraham Palmer, Ph.D. “It’s integrally important to physical and mental health.

“A person’s economic success is tied to delay discounting,” he continued. “Take seeking higher education and saving for retirement as examples — these future rewards are valuable in today’s economy, but we’re finding that not everyone has the same inclination to achieve them.”

The next stage of research, Palmer said, will be to use rodent models to determine if altering genes linked to delay discounting has any impact on behavior. If it does, he theorized, scientists may be able to determine how the drive for instant gratification works on a molecular level.

The study1 was published December 11 in the journal Nature Neuroscience.

1 Sanchez-Roige, Sandra, et al. “Genome-Wide Association Study of Delay Discounting in 23,217 Adult Research Participants of European Ancestry.” Nature Neuroscience, Nov. 2017, doi:10.1038/s41593-017-0032-x.