Riding skills can be impaired not only by alcohol but also by both legal and illegal drugs. This includes over-the-counter drugs, prescription medications, and illicit substances, all of which can affect a rider's cognitive and motor functions essential for safe riding. These substances can alter a person's ability to concentrate, judge distances, and make quick decisions, thus increasing the risk of accidents while riding a motorcycle. Therefore, it's important to understand that any drug impacting brain function can potentially impair riding abilities.