The effects of peer pressure
Peer pressure is when a *group of friends or a single one influences a youth on changing his\her behavior and beliefs. The effects of peer pressure could be positive or negative, depending on the way peers influence him\her. For instance, a youth can be pressured to have a better academic performance or to participate in a volunteer charity work. On the other hand, peer pressure is one of the reasons why young people **may become addicted to drugs and alcohol.
*"Peer pressure" can be applied to, for example, culture, organisations, governments or other institutions, not only individuals.
**To be definite, you should be supported by facts, so, this is why it is best to use "may" in this context.