Excessive and/or chronic substance use can have a substantial effect on neuropsychological functioning. Substance use disorders arise when direct harm arises from substance use and/or when a person requires more and more of a substance to achieve the same level of intoxication and experiences withdrawal symptoms when they have not taken the substance for some time (i.e., substance dependence).
Alcohol Related Cognitive Impairment
Alcohol is the most widely used psychotropic substance in the western world. Significant chronic alcohol use results in diminished cognition over time, even when a person is sober. A severe and irreversible result of significant long-term alcohol consumption is the Wernicke-Korsakoff Syndrome. This syndrome results in a dramatic loss of ability to learn and remember new information, amongst other cognitive and behavioural difficulties. Those with the syndrome have clear physical brain changes, particularly to the mammillary bodies, which are essential structures in the memory network.