A study says that consumption of marijuana at a fairly early age can trigger the risk of depression and negative feelings that dominate.
According to research published in the journal Biological Psychiatry: Cognitive Neuroscience and Neuroimaging, young people with dependence on these substances undergo changes in brain function and disturbance of emotional sources so that the risk of psychosis.
The change is most evident in those who start using marijuana at a young age.
The findings found a long-term negative effect on the use of severe marijuana in behavior and brain function.
Study leader Dr. Peter Manza, Dardo Tomasi and Nora Volkow from the National Institute on Alcohol Abuse and Alcoholism, Bethesda, Maryland; examined 441 young adults and compared with a small group of 30 marijuana users through 30 controls.
People with severe marijuana use have very high connectivity in brain regions that are essential for reward processing and habit formation.
The same area has also been pegged in the development of psychosis in previous studies.
"These brain imaging data link the changes in brain systems involved in rewards and psychopathology and chronic marijuana abuse, suggesting that this mechanism of heavy drug use may lead to depression and other, more severe forms of psychiatric illness," Dr Cameron Carter.
Brain changes are also associated with increased emotional feelings, especially alienation, in which people perceive hostility or rejection from others.
The association with potential biological mechanisms of feelings of alienation often increases significantly in people with cannabis dependence. Marijuana can also damage lives.
"Interestingly, excessive connections are very strong in individuals who start using marijuana early in adolescence", Dr. Manza added.
According to the researchers, adolescence is a critical period of brain development, making early use of marijuana very harmful..