Brain micro-architecture and disinhibition: a latent phenotyping study across 33 impulsive and compulsive behaviours
Publication: Neuropsychopharmacology
Rafa Romero-Garcia, Roxanne W. Hook, Jeggan Tiego, Richard A. I. Bethlehem, Ian M. Goodyer, Peter B. Jones, Ray Dolan, Jon E. Grant, Edward T. Bullmore, Murat Yücel & Samuel R. Chamberlain
12 September 2020
Summary
Impulsivity refers to behaviours that are inappropriate, risky, unduly hasty, and that lead to untoward outcomes. By contrast, compulsivity refers to repetitive, perseverative actions that are excessive and inappropriate to a given situation.
For example, an individual with attention-deficit hyperactivity disorder (ADHD) may manifest impulsive problems such as making a statement they regret to a colleague; or jumping a red light; whereas an individual with obsessive-compulsive disorder (OCD) may repeatedly (i.e. compulsively) check the front door is locked, for hours per occasion.
It is well known that impulsive and compulsive problems often occur together in the same individual, but very little is known about processes in the brain that may contribute to this. To address this, in this study supported by the NIHR Cambridge BRC researchers studied brain structure and impulsive-compulsive problems in young adults, and the relationship between them.
They found that most of the occurrence of impulsive and compulsive problems could be explained by difficulty regulating urges and habits, known as ‘disinhibition’. Disinhibition was related to changes in the structure of the brain, especially in regions important for top-down control such as the frontal lobe.
The study identified a new brain-based vulnerability marker contributing to impulsive and compulsive problems. Unlike previous research, the findings go beyond traditional psychiatric diagnostic boundaries, by examining a comprehensive range of behaviors, rather than only one disorder studied in isolation.