Which of the following is a negative effect of alcohol consumption?

Memory problems are indeed a well-documented negative effect of alcohol consumption. Alcohol can impair cognitive function, including the ability to form new memories and recall existing ones. This impairment can range from short-term memory lapses to more serious long-term cognitive deficits, especially with heavy or prolonged use.

In contrast, the other options may seem beneficial in certain contexts but do not accurately reflect the overall impact of alcohol. For example, weight loss might occur initially due to reduced appetite or the caloric content of alcohol not being recognized as food energy; however, chronic alcohol consumption often leads to weight gain due to increased calorie intake and fat storage. Although some may report feeling more concentrated after consuming alcohol in small doses, this is misleading, as it typically leads to decreased cognitive function over time. Lastly, alcohol consistently deteriorates motor skills rather than improving them, increasing the risk of accidents and impairing coordination. Thus, the negative cognitive impact of alcohol, particularly regarding memory, underscores its detrimental effects on overall well-being and mental health.