Overeating and food addiction in Major Depressive Disorder: Links to peripheral dopamine

The concept of food addiction refers to addiction-like behaviours that develop in association with the intake of highly palatable foods. Previous research indicates that a high proportion of individuals with Major Depressive Disorder (MDD) meet the criteria for food addiction, and are also at an increased risk of weight gain and chronic disease. In the central nervous system, dopamine is a neurotransmitter associated with reward salience and food intake, whereas peripheral dopamine is involved in sympathetic stress regulation, digestion and gastrointestinal motility. However, little research has examined relationships between peripheral dopamine, depressive symptoms and problematic eating behaviours in MDD. Biometrics, psychopathology and plasma dopamine levels were compared between participants with MDD (n = 80) and controls (n = 60). Participants were sub-categorised into those meeting or not meeting Yale Food Addiction Scale (YFAS) criteria. Psychometric measures of mood and appetite were used to assess MDD symptoms, problematic eating behaviours and food-addiction related symptoms. Twenty-three (23; 29%) MDD participants met the Yale criteria for food addiction. Depressed individuals meeting YFAS criteria had significantly greater psychopathology scores for both mood and eating compared to depressed individuals not meeting YFAS criteria and controls. A significant interaction between food addiction status and sex was also observed for plasma dopamine levels. Plasma dopamine levels correlated positively with disordered eating behaviours in females, and negatively in males. The results provide evidence that depressogenic excess eating and weight gain are associated with peripheral dopamine levels. Longitudinal research is warranted investigating endocrine dysregulation and excess eating in MDD, which may inform interventions and reduce chronic disease risk in affected individuals.