A long-term study of nearly 1,000 New Zealanders tracked them from birth through to 32. The study looked at those people who began drinking and using marijuana regularly before their 15th birthday. Some of the children came from abusive, criminal or substance-abusing households and had behaviour problems while others came from more stable backgrounds. The children from the more stable backgrounds who were early drug users ended up with the same problems as the at-risk children who did not take drugs and were 3.6 times more likely to be dependent on substances at 32. They were also more likely than the other children from stable backgrounds to end up with a criminal conviction and/or a herpes infection. Early pregnancies, a pattern of school failure, substance dependence, sexually-transmitted disease and criminal convictions were common patterns among the early drug users.
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