Does one have to use drugs for a long time in order for the drugs to negatively affect them? No. The long term effects of drug abuse can be very bad but so are the short term effects. Some short term effects of drug use. - Drugs will cloud your judgment. You'll make bad decisions. Bad decisions that could cost you something valuable. - Drugs will unleash the daredevil in you. Many people have lost their lives doing things they wouldn't have done if they were sober. - You'll end up being friends with other addicts, people who will not be a good influence . . . Not great are they? Drugs aren't fun.