Impulsivity

Impulsivity Is a Multidimensional Construct

Impulsivity is a multifaceted construct. For example, impulsivity can be functional or dysfunctional. Functional impulsivity refers to the tendency to make decisions quickly with little forethought when such strategies are optimal under certain circumstances. Conversely, dysfunctional impulsivity refers to the tendency to make rapid and imprudent decisions due to an inability to use a slower and more methodical approach. Functional impulsivity is thought to be adaptive for making decisions when time is limited or when facing easy-to-solve problems. In contrast, as shown in the next section, dysfunctional impulsivity has been related to poor decision-making and impaired adaptive functioning across the life span.

Dysfunctional Impulsivity and Related Outcomes

Dysfunctional behavioral impulsivity has been studied extensively and related to poor mental health, physical health, and social, educational, and occupational outcomes. For example, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, has devoted an entire chapter to disorders that stem from poor impulse control. The chapter titled “Disruptive, Impulse-Control, and [Page 1115]Conduct Disorders” includes oppositional defiant disorder, conduct disorder, and intermittent explosive disorder. In addition, attention-deficit/hyperactivity disorder has been theorized to stem from impulsivity, especially deficits in response inhibition and ability to wait for a reward. Moreover, individuals with high levels of impulsivity are at elevated risk of substance use and addictive disorders (e.g., alcohol use disorder, stimulant use disorder, gambling disorder), eating disorders (e.g., bulimia nervosa, binge eating disorder), obsessive-compulsive and related disorders (e.g. hoarding disorder, trichotillomania, excoriation disorder), bipolar disorder, aggressive behavior, delinquency/criminality, obesity, and suicidal behavior.

In short, impulsivity has been related to multiple mental disorders and other impairments in healthy functioning. Thus, dysfunctional impulsivity has been proposed to be an important genetic and behavioral risk marker (i.e., endophenotype) for the development of diverse psychopathologies, particularly disruptive disorders, attention-deficit/hyperactivity disorder, and substance use disorders.

Cognitive and Neurobiological Aspect of Impulsivity

Impulsivity has been linked to deficits in executive functioning—cognitive skills that are important for controlling impulses, planning actions, and making decisions in our daily life. Using neuroimaging technology, investigators have identified brain networks that drive impulsive behavior and those that exert inhibitory control. The basal ganglia (i.e., dorsal and ventral striatum), hippocampus, amygdala, and other subcortical areas of the human brain comprise the reward system that drives impulsive behavior. Conversely, the prefrontal regions of the brain (i.e., anterior cingulate cortex, dorsal and ventral prefrontal cortex) are thought to be the cognitive control system essential for controlling immediate impulses. Hyperactivity (or overcontrol) in the reward system may result in an automated tendency for impulsive behavior. If the cognitive control system (i.e., prefrontal regions in the brain) is unable to exert control over the reward system, this results in the execution of impulsive behavior. The reward and the control brain networks are communicated via the neural pathways in the brain that transmit dopamine and serotonin (i.e., two types of neurotransmitters in the brain for communication between neurons). Dopamine plays an important role in cognitive and motor control, motivation, and reward. Serotonin plays an important role in the ability to delay immediate reward (i.e., delay of gratification).

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