Early Use. Although taking drugs at any age can lead to addiction,
research shows that the earlier a person begins to use drugs the
more likely they are to progress to more serious abuse. This may
reflect the harmful effect that drugs can have on the developing
brain; it also may result from a constellation of early biological and
social vulnerability factors, including genetic susceptibility, mental
illness, unstable family relationships, and exposure to physical
or sexual abuse. Still, the fact remains that early use is a strong
indicator of problems ahead, among them, substance abuse and
addiction.