Alcohol is addictive and regular use can lead to dependence and addiction/alcoholism, even in college-age students. People with a family history of substance abuse are 4 - 10 x more likely than the general population to develop substance abuse and addiction in their lifetime, and tend to do so at an earlier age. People who begin drinking before age 15 are 5x more likely to develop substance abuse issues in their lifetime, as well. Some warning signs of dependence are: more frequent use; needing more and more to get the same effect (tolerance); spending time thinking about and planning for alcohol use; spending more money than you have on it; missing class or failing to finish assignments because of alcohol use; continuing to drink despite repeated negative consequences; making new friends who drink a lot and neglecting old friends who don't; finding it's hard to be happy without regular alcohol use, etc. Warning signs of addiction include all of the above and physical withdrawal symptoms after a drinking episode such as anxiety, tremors, sleep disturbances, hallucinations and seizures.