Which substance is the most commonly abused drug that leads to altered mental status in patients?

Ethanol, the principal ingredient in alcoholic beverages, is the most commonly abused drug associated with altered mental status in patients. When consumed, ethanol affects the central nervous system by acting as a depressant. This can lead to a range of symptoms including diminished cognitive function, impaired motor skills, confusion, and, in severe cases, loss of consciousness or respiratory depression.

Ethanol is widely consumed across various demographics, making it far more prevalent in clinical presentations compared to other substances in the options listed. Its legal status and the social acceptance of alcohol consumption contribute to its widespread use and potential for abuse, increasing the likelihood of encountering patients with altered mental status due to ethanol intoxication in medical settings.

While cocaine, marijuana, and methanol can also lead to altered mental states, they tend to be less common in terms of overall frequency of abuse and associated medical emergencies in comparison to ethanol. Methanol, though toxic and capable of causing significant impairment, is less frequently encountered as a drug of abuse among the general population.