Irreversible harm?

Studies are increasingly showing that marijuana is not the soft drug that many users believe it to be.

A Melbourne research team has found that weekly cannabis use in teenagers "predicted an approximately two-fold increase in the risk for later depression and anxiety." So marijuana, it seems, should not be associated with being cool and relaxed, but the very opposite: with low, depressed moods and being anxious.

Meanwhile a Dutch research team from the University of Maastricht has found that "exposure to cannabis during adolescence and young adulthood increases the risk of psychotic symptoms later in life."

Why does cannabis use by young people cause such problems later in life? The answer is quite disturbing. It's increasingly thought that our brain development continues until at least our early 20s. At this late age the frontal lobes are still developing and increasing our more sophisticated mental abilities.

It's thought that cannabis use by teenagers impairs this important stage of mental development. What this means is that some of the damage done by marijuana use may be irreversible. Young people may be missing out on developing "higher cognitive functions" by their use of cannabis.