Stereotypically, when one thinks of ‘impulsivity’ as a symptom of a psychiatric disorder, it is almost inevitably linked to Attention Deficit Hyperactivity Disorder (ADHD). Similarly, compulsivity is associated with the prototypical compulsive disorder – Obsessive Compulsive Disorder (OCD). Dr Bavi Vythilingum examined impulsivity and compulsivity at a recent Lundbeck South Africa Psychiatry Institute and examined the role impulsivity and compulsivity play in numerous different psychiatric disorders.
Deficits here result in rapid, poorly thought out decisions.
Logically, before delving into the association of these symptoms and psychiatric disorders, it would make sense to have a working definition for each of these constructs. Impulsivity is defined as a predisposition to rapid, unplanned actions in response to internal and external stimuli. Compulsivity is defined as repetitive and functionally impairing overt and covert behaviour without adaptive function, with behaviours performed in a habitual manner. Impulsivity can further be divided into three different subgroups. These include motor impulsivity, which involves noradrenalin and decision making impulsivity, which involves 5-HT and dopamine. Deficits here result in rapid, poorly thought out decisions. The final subgroup is choice impulsivity, which involves dopamine and affects delayed gratification. Compulsivity is less well defined. It has neurocognitive components and can result in behavioural disinhibition as well as behavioural adaptation.
When thinking about disorders on an impulsivity / compulsivity spectrum, could eating disorders be classified as behavioural addictions?
When compulsions occur or when compulsive behaviour takes place, the patient experiences a loss of control and an inability to stop the particular behaviour. When examining different psychiatric disorders, where both impulsivity and compulsivity are present, one look at substance addiction, or gambling disorder. Both disorders have elements of impulsive and compulsive behaviour, and the compulsive behaviours increase as the addiction progresses. High choice impulsivity is a predictor of poor treatment response, and increased risk of relapse, whereas reduced choice impulsivity is seen in addicts who are abstinent. We can use this type of information to guide clinical decision making, as patients with high choice impulsivity benefit greatly from inpatient care, and Cognitive Behavioural Therapy (CBT), both which help break the habit formation. When thinking about disorders on an impulsivity / compulsivity spectrum, could eating disorders be classified as behavioural addictions?
As with substance abuse above, there are elements of compulsivity and impulsivity. In Anorexia Nervosa (AN), Bulimia Nervosa (BN) and Binge Eating Disorder there is a persistence of these behaviours, despite negative consequences. OCD is another disorder which is very biologically driven, with different thought dimensions. Dopaminergic mechanisms are thought to be responsible for habit learning, and hence in long established OCD, low dose antipsychotics work very well as adjunctive therapy. Other disorders which were explored include ADHD, Parkinson’s Disease, Trichotillomania and impulsivity in depression, anxiety and suicidal behaviour.
In conclusion, both constructs serve a range of disorders. There are distinct but overlapping neural mechanisms involved and these can, and should, serve as targets for different treatment strategies.
