Various states have been trying to follow California's lead and make marijuana for medical purposes legal. Marijuana can relieve pain, decrease nausea, and help sleep in ways that do not cause any addiction or negative side effects. Recent findings have also shown that marijuana can have the potential to treat attention deficit hyperactivity disorder. The only drawback is that the illegal status of marijuana makes it difficult to fund the research, and instead it is unfairly grouped with dangerous drugs like cocaine, heroin, and methamphetamine even though they share no common characteristics.