TEEN MARIJUANA USE FOSTERS DEPRESSION
Research from the University of Pittsburgh followed 158 boys and young men until the age of 22. Brain scans revealed that the teenagers using marijuana between the ages of 14 and 19 had a higher risk of depression as young adults. Marijuana users also had the lowest educational achievements. They suffered impaired connectivity in the nucleus accumbens part of the brain, which plays a central role in the reward circuit tied to two essential neurotransmitters: dopamine, which promotes desire; and serotonin, which affects satiety and inhibition.
Another recent study of 521 Washington State University students noted that depressed 12-to-15-year-olds were more likely to be using marijuana by age 18.