To paraphrase a former First Lady, “What goes on in the White House is never as important as what goes on in your house.”

As the evidence mounts of the negative effects of medical marijuana laws in various states, it’s even more important for parents to recognize that marijuana needs to be on their parenting radar screen.

A Colorado study shows some of these impacts, where nearly 74 percent of a sample of teenagers receiving addiction treatment in that state told researchers they used medical marijuana that was recommended for someone else.

This news should be of no surprise because increased availability of marijuana is highly associated with increased use. Studies have shown that marijuana is not a safe, benign drug. It’s a highly addictive drug. When smoked it contributes to pulmonary damage. It significantly impairs judgment, and is associated with poor performance in school. Its use has also been linked to contributions to impairment on important measures of life achievement, including physical and mental health, cognitive abilities, social life and career status.

Marijuana is a drug that’s widely used by teens and young adults. Among teens aged 12 to 17, according to the Substance Abuse and Mental Health Services Administration, after several years of declines, current marijuana use increased in 2009 and again in 2010, to 7.4 percent of the population. Among young adults aged 18 to 25, almost 30 percent used marijuana in the past year, with almost 6.3 million young adult users in the past month.

Marijuana use is now more prevalent among teens than cigarette smoking. Marijuana smoke contains 50-70 percent more carcinogenic hydrocarbons than tobacco smoke. Moreover, the typical weed available to adolescents these days is so much more potent compared to the marijuana used by prior generations. This increased potency is particularly concerning in light of recent scientific findings that marijuana use deleteriously affects brain development, particularly in areas related to mood, reward, and learning.

Medical marijuana laws have made parents’ jobs tougher, no doubt about it. Although the provisions of the statutes differ, as of early July medical marijuana statutes had been signed into law in 17 states and the District of Columbia.

Parents are a mighty lobbying force – at the local, state and national levels – particularly when they act in groups. We are not suggesting that parents shouldn’t try to influence government at any one of these levels.

But because governments move slowly and not always in everyone’s best interests, parents can (and should) influence what goes on in their households. Science will continue to inform the public and seek solutions. But as the constant in a child’s life – with protective instincts that can be brought out by science but not replaced – it’s the parents who are the first lines of defense for their children.

Ken C. Winters, PhD & Amelia Arria, PhD

Dr. Winters is the Associate Director, Dr. Arria the Scientific Director, of the Parents Translational Research Center (PTRC) of the Philadelphia-based Treatment Research Institute. The PTRC is a NIDA-funded Center dedicated to developing practical, science-based tools for parents and other caregivers faced with challenges related to adolescent substance abuse.