ADHD in adults is poorly investigated and, although several studies have reported associations between this disorder and abnormal eating behaviour, so far it had not been described associations between ADHD and eating disorders in adults.

The results of the study conducted by researchers from the group of Psychiatry and Mental Health at the Bellvitge Biomedical Research Institute (IDIBELL) and the Unit of Eating Behaviour Disorders of the Bellvitge University Hospital, with the colaboration of the Department of Psychiatry of the Vall d'Hebron University Hospital, have been published in the online edition of the journal BMC Psychiatry.

Impulsivity

ADHD symptoms related to hyperactivity such as impulsivity are very present in patients with eating disorders who participated in the study, but not in everyone, as explained Fernando Fernández-Aranda, head of the Unit of Eating Behavior Disorders of the Bellvitge University Hospital and IDIBELL researcher. These disorders "are found mainly in patients with a more impulsive personality: people suffering bulimia, binge eating disorders and unspecific eating disorders. On the other hand, more restrictive anorexic patients and those with more ability to control themselves do not show these symptoms."

This research has allowed to develop a model that could be clinically useful for early detection of risk factors which could lead to an eating disorder.

ADHD symptoms are positively associated with impulsive personality traits and age. More impulsive and older patients have an increased risk of developing an eating disorder. Impulsivity is also associated with a greater severity of the disorder.

Moreover, these impulsivity ADHD symptoms are associated with low self-direction, a character trait that involves the ability to planning and achieving objectives in the medium and long-term. "So, patients with ADHD symptoms also have a worse prognosis because it is harder for them to be able to accomplish a treatment," says Fernández-Aranda.

Reward system

According to Fernández-Aranda, this model will be useful not only in the clinic but also for investigating brain circuits that regulate the reward system and that are similar in several behavioural pathologies such as eating disorders, pathological gambling and other behavioural addictions.