Marijuana has been used in the treatment of psychiatric disorders, such as depression and bipolar disorder, for thousands of years across the world. In the United States, it has been praised in medical journals from the 1600s as having therapeutic qualities that aid in the treatment of mood disorders. Despite its history in psychiatric medicine, medical marijuana is not commonly used to treat mental disorders in any state but California.

Marijuana has been present in known cultures dating back to the Stone Age, however laws leading to the prohibition of cannabis did not arise in the United States until the 20th century. Despite the legalization and decriminalization of marijuana in several countries across the world for both personal use and medicinal use, the plant is still subject to harsh criticism. The global war on drugs is slowing moving towards a new direction of lesser laws regulating the use of marijuana.