Studies Say ADHD, Substance Abuse, and Binge Eating Disorder Genetically Linked
According to twin studies from Linköping University, Sweden, the strong association between adult ADHD (attention deficit hyperactivity disorder), substance abuse, and binge eating disorder may be partially explained by genetic links – in both men and women.
Study author Andrea Johansson Capusan, PhD:
“Clinically, the results of this thesis support that ADHD in adults be considered and addressed in adults with substance use disorder or binge-eating behavour. Given the common genetic risk factors and the role of the early childhood environment, family interventions should be considered for these populations.”
Previous studies have found a higher incidence of ADHD in adults who have substance use disorders when compared to the rest of the population, and research has also shown that ADHD and binge eating disorder often occur together.
About The Studies
Researchers conducted 4 related studies, each of which used self-reported information on ADHD-related symptoms from 18,167 twins aged 20-46 years in the Swedish Twins Registry.
One study focused on ADHD symptoms and alcohol use disorder, illicit drug use, polysubstance abuse, and nicotine use. Results revealed showed strong correlations between symptoms of ADHD and substance abuse.
ADHD symptoms were associated with 88% increased odds of alcohol abuse, 358% increased odds of alcohol dependence, 227% increased odds in illicit drug use, and 33% increased odds of nicotine use.
The second examined alcohol dependence exclusively, and focused on sex differences. Results found that shared genetic factors could explain nearly two-thirds of the association between alcohol dependence and adult ADHD, and no meaningful differences were found related to sex.
The third study examined childhood maltreatment, neglect, and abuse. Information within each twin pair was compared to assess the role of genes and environment. Results suggested that part of the association between childhood maltreatment and adult ADHD could be explained by “environmental confounding within the family.”
The final study looked at links between binge eating and adult ADHD. The finding suggested that 91% of the adult ADHD/binge eating association could be accounted for by shared genetic factors.
Adult ADHD symptoms were associated with 365% increased odds of binge eating behavior, 255% increased odds of binge eating disorder, and 209% increased odds of bulimia nervosa.
“Given increasing evidence that ADHD and its comorbidities with other conditions have a significant degree of shared heritability, it is important that health providers are educated in interpreting and communicating genetic and environmental risks to their patients.”
However, researchers noted that environment was important, as well. Findings revealed that childhood maltreatment contributed to adult ADHD symptoms. Other studies have shown that other environmental risk factors include low income, family adversity, and hostile parenting.
~ G. Nathalee Serrels, M.A., Psychology