New finding offers promise in researching depression together with obesity 

Is problem-solving therapy effective in treating individuals who have both depression and obesity? Researchers at the University of Illinois Chicago have identified an important step toward discovering how and why therapies and treatments work. 

Research published in The American Journal of Clinical Nutrition has shown that problem-solving therapy led to short-term changes in the amygdala — the gateway to emotion regulation in the brain.  Dr. Jun Ma, Beth and George Vitoux Professor of Medicine at the UIC department of medicine, is a senior author of the study: “Problem-solving therapy–induced amygdala engagement mediates lifestyle behavior change in obesity with comorbid depression: a randomized proof-of-mechanism trial.” 

“The goal of the study is to explore whether an intervention for comorbid obesity and depression has an effect on brain function as a causal mechanism that leads to behavior change and symptom improvement,” Ma said. 

In previous research, depression has been characterized by heightened amygdala activity along with a loss of amygdala regulation. Changes in amygdala activity correlate with responses to cognitive-behavioral therapy for depression and antidepressants. The new study is the first to investigate these neural targets in response to depression treatment for weight loss and behavior change among patients with both obesity and depression using a randomized clinical trial. 

For the current study, adults with both obesity and depression received problem-solving therapy for depression for the first two months in a yearlong, integrated behavioral treatment for both conditions. They underwent functional MRI brain imaging at the beginning of the study, then after two months. Their body mass index (BMI), physical activity and diet were measured at the study’s beginning, as well as after 12 months. Neural target changes were measured and compared with the control group, which received no problem-solving therapy. 

The research found amygdala changes associated with physical activity levels as well as energy expenditure. The neural target changes at two months predicted the improved behavioral outcomes after 12 months, which is important to demonstrate potential causal mechanisms, Ma said. 

“The goal is to study the causal mechanisms and understand how and why behavioral treatments such as problem-solving therapy work so that we can more precisely target the mechanism in order to improve treatment efficacy for patients,” Ma said. “These findings give us a promising direction for future research to hopefully confirm this causal pathway.” 

Ma and Dr. Leanne Williams at Stanford University are principal investigators. The study’s additional authors include Nan Lv, Wesley Lefferts and Olusola Ajilore of UIC; Lan Xiao, Andrea Goldstein-Piekarski, Joseph Wielgosz, Phillip Lavori, Patrick Stetz, Lisa Rosas and Trisha Suppes of Stanford University; Janine Simmons, National Institute on Aging, National Institutes of Health; Joshua Smyth, Pennsylvania State University; Elizabeth Venditti, Pittsburgh School of Medicine; Megan Lewis, RTI International; and Mark Snowden, University of Washington, Seattle. 

This work is funded in part by the National Institutes of Health Science of Behavior Change Common Fund Program through an award administered by the National Heart, Lung, and Blood Institute (UH2HL132368 and UH3HL132368).