What besides alcohol may impair a persons ability to drive safely?

Aside from alcohol, under the influence of prohibited drugs could also impair a persons ability to drive safely. A person under the influence of prohibited drugs would be hard to control as they are experiencing the effect of the drugs they have taken. These drugs would target directly the brain affecting the person's thinking and reasoning. It could lead to hallucinations, paranoia, loss of self control, impaired judgement, aggressiveness and others. With these problems, surely, it would greatly affect driving manners of the person since he cannot think straight at this moment which could lead to accidents and, worse, would cause death.