Marijuana is toxic for the brain and here's why:

Published in the Journal of Alzheimer's Disease, researchers using single photon emission computed tomography (SPECT), a sophisticated imaging study that evaluates blood flow and activity patterns, demonstrated abnormally low blood flow in virtually every area of the brain studies in nearly 1,000 marijuana compared to healthy controls, including areas known to be affected by Alzheimer's pathology such as the hippocampus.

Hippocampus, the brain's key memory and learning center, has the lowest blood flow in marijuana users suggesting higher vulnerability to Alzheimer's. As the U.S. races to legalize marijuana for medicinal and recreational use, a new, large scale brain imaging study gives reason for caution. Published in the Journal of Alzheimer's Disease, researchers using single photon emission computed tomography (SPECT), a sophisticated imaging study that evaluates blood flow and activity patterns, demonstrated abnormally low blood flow in virtually every area of the brain studies in nearly 1,000 marijuana compared to healthy controls, including areas known to be affected by Alzheimer's pathology such as the hippocampus.

All datawere obtained for analysis from a large multisite database, involving 26,268 patients who came for evaluation of complex, treatment resistant issues to one of nine outpatient neuropsychiatric clinics across the United States.

During the teenage years, the brain is undergoing rapid development. A process called myelination takes place, coating neurons with a protective white-colored sheath that helps speed communication in the brain. This important process, which gives the brain’s white matter its color, isn’t completed until a person’s mid-20s. Heavy cannabis use as an adolescent can interfere with this process, damage the brain’s white matter, and result in a higher incidence of impulsivity, especially in teens who started smoking marijuana prior to the age of 16.