Public Release: 

Consistent links between capacity to delay gratification and ADHD, obesity

McMaster University

Hamilton, Ont. (June 14, 2016) - Two new studies led by researchers at McMaster University and St. Joseph's Healthcare Hamilton have found that individuals diagnosed with ADHD or obesity are more likely to choose smaller immediate rewards over larger future rewards.

This reduced capacity to delay gratification in many individuals diagnosed with ADHD or obesity may lead to new approaches for the clinical treatment of these conditions.

The studies, led by Drs. James MacKillop and Michael Amlung of the Peter Boris Centre for Addictions Research at McMaster University and St. Joseph's Healthcare Hamilton, have been published in Biological Psychiatry: Cognitive Neuroscience and Neuroimaging and Psychological Medicine.

The findings from these new studies parallel a 2011 study conducted by the authors that found that the ability to delay gratification was reduced in individuals diagnosed with addictive disorders.

"In the context of addictions, there is an increasing appreciation that we need to improve treatment that we provide for patients who substantially devalue future rewards," said MacKillop. "These studies suggest that a simple assessment that measures this phenomenon may also help clinicians to better understand some of their patients that have been diagnosed with ADHD and obesity."

The studies were meta-analyses, or studies that combine the findings across many previous investigations to detect consistent or inconsistent patterns of findings. In the case of the ADHD study, the meta-analysis combined the findings from 21 previous studies including almost 4,000 participants. In the case of the obesity study, the meta-analysis combined the findings from almost 39 studies including over 10,000 participants.

Although the results of prior research appeared to be mixed, these new studies found a highly consistent reduction in capacity to delay gratification in relation to both clinical conditions.

"While not all individuals diagnosed with ADHD and obesity display this pattern of reduced capacity to delay gratification, the connection between this phenomenon and addictions as well as these clinical conditions is clear," said Amlung.

"In the context of obesity specifically, these findings may help inform clinical approaches to weight management that increase individuals' focus toward the longer-term rewards of weight loss."

A second important finding in both studies was that, although the methods varied considerably across the previous studies, reanalyzing the data based on different methods did not appreciably alter the overall findings.

"These studies suggest that, despite different experimental tasks, ages and study designs, immediate reward orientation is robustly elevated in both ADHD and obesity," said Dr. MacKillop.


The studies were funded in part by grants from the National Institutes of Health and the Peter Boris Centre for Addictions Research.

Note to Editors: A photo of James MacKillop and Michael Amlung can be down loaded at

Photo cutline: (L to R) Drs. James MacKillop and Michael Amlung of the Peter Boris Centre for Addictions Research at McMaster University and St. Joseph's Healthcare Hamilton.

Media Contact:

Maria Hayes
Senior Public Affairs Specialist | Public Affairs Department | St. Joseph's Healthcare Hamilton | 225 James Street South |Hamilton, ON | T: 905-522-1155 ext. 33506 | E: | Twitter: @STJOESHAMILTON |

Veronica McGuire
Media Relations Co-ordinator | Faculty of Health Sciences | McMaster University | 1280 Main Street West-HSC-2E48 |Hamilton, ON | T: 905-525-9140 ext. 22169 | E: |

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About McMaster University

McMaster University, one of four Canadian universities listed among the Top 100 universities in the world, is renowned for its innovation in both learning and discovery. It has a student population of 23,000, and more than 150,000 alumni in 128 countries.

About St. Joseph's Healthcare Hamilton

St. Joseph's Healthcare Hamilton is a regional leader in patient-centred care providing acute care, research, teaching, community and international outreach programs throughout our network. Since being founded by the Sisters of St. Joseph in 1890, our hospitals span three specialized campuses in the Greater Hamilton Area (Charlton Campus, West 5th Campus and King Street Campus), with St. Joseph's Villa Dundas providing long-term care and St. Joseph's Home Care providing personalized home care traversing the reach of our region. For more information about St. Joseph's Healthcare Hamilton, please visit

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