depression

Brain abnormalities and memory problems were observed in these individuals in their early twenties, two years after they had stopped using marijuana. The cannabis users were noted to have striatal, globus pallidus, and thalamus changes showing these brain regions appearing to shrink and collapse inward. These individuals also had poorer working memory. The earlier the age of cannabis use, the more dramatic the brain changes and memory deficits were noted to be.
Not only does it appear that cannabis use itself is a potential precursor to future drug use, but the age of first use of cannabis and the frequency of cannabis use seem to also be predictors of future substance abuse issues. Studies have shown that over two-thirds of those under the age of 18 who have been admitted to a drug treatment program identify cannabis as their substance of choice.
” One important characteristic that defines a substance use disorder is “an underlying change in brain circuits that may persist beyond detoxification, particularly in individuals with severe disorder"