Tobacco, alcohol and illegal drugs affect boys and girls differently. Here's what you should know:

Parents have enormous power over a child's well-being but too many fail to appreciate and use this power. Study after study has shown: Parental involvement makes a critical difference in children's lives. Parents can influence their children if they reach them early and if they continue to reinforce strong values and a positive message throughout their teen years.

TOBACCO:

Everybody knows that smoking can cause the biggest health killer...heart disease, stroke and cancer. Smoking can also contribute to infertility...and guys...be aware: new studies show it can also affect potency as well. If you smoke, you're playing Russian roulette with your sexual function. in fact, if you smoke, you're about twice as likely to have erectile dysfunction. Smokeless tobacco carries many of the health risks of cigarettes. Overall, male students are significantly more likely than female students to have used smokeless tobacco.

ALCOHOL:

When you start to drink at a young age, you are also putting yourself at greater risk later on. Kids who started to drink before age 15 are four times more likely to get hooked on alcohol than those who began to drink after age 21. Alcohol robs you of your ability to think and can damage your body by creating stomach problems, loss of memory, impotence, liver damage and more. Binge drinking brings with it serious alcohol-related problems, such as unprotected and unplanned sex, getting into trouble with police, damage to property and getting hurt or injured, driving under the influence or riding with a driver who was high or drunk, getting behind in school work or doing something you later regret. No question about it, underage drinking can damage and jeopardize your health and lifetime prospects. And boys are more likely than girls to report heavy drinking.

ILLEGAL DRUGS:

There are stronger forms of marijuana available to kids today than in the 1960s which means stronger effects. There are serious consequences to marijuana use, especially for teens, which include impairment of short-term memory, concentration and motor skills, critical for a child's intellectual and social development; greater likelihood of use of another illegal drug such as cocaine or heroin; increased likelihood of having unprotected sex or sex with multiple partners, leaving them at greater risk of pregnancy, AIDS and other sexually transmitted diseases; possible long-term physical and psychological dependence and/or slowed reaction time, impaired coordination and decrease attention span, leading to increased highway accidents and fatalities.