Executive function

Executive function is the set of higher-order mental skills, including working memory, inhibitory control and mental flexibility, that allow a person to plan, focus, and manage behavior toward goals.

These skills depend heavily on the prefrontal cortex and its connections with deeper brain structures, and they mature slowly, continuing to develop into the mid-twenties. Working memory holds information in mind while using it, inhibitory control suppresses impulses and distractions, and cognitive flexibility allows switching between tasks and viewpoints. Together they support organization, time management, decision making and emotional regulation.

Executive function is measured with neuropsychological tests such as the Stroop task, trail-making tests and digit span, and with rating scales completed by the person, parents or teachers. Difficulties are a central feature of ADHD and are also seen after concussion and in depression, sleep deprivation, chronic pain and dementia. THC impairs executive function while it is active, an effect that is well documented in driving and laboratory studies, and CBD has been examined for effects on these skills in a small number of early studies with no established conclusions.