Which of the following is NOT a sign of potential substance abuse among youth?

The option indicating increased involvement in sports is not considered a sign of potential substance abuse among youth. Engaging more actively in sports typically reflects positive behavior and a healthy outlet for energy and stress. Sports involvement often promotes discipline, teamwork, and physical well-being, which are generally viewed as constructive activities.

In contrast, the other options highlight behaviors that could indicate a struggle with substance use. Declining academic performance often suggests a distraction or lack of focus that can accompany substance abuse. Withdrawal from family reflects social and emotional changes, which can be indicative of underlying issues, including substance use. Similarly, changes in behavior, such as becoming more secretive or exhibiting mood swings, can signal that a youth may be experiencing difficulties related to substance abuse. Therefore, increased involvement in sports stands out as a positive indicator rather than a potential warning sign.