In the United States, more than 21 million people suffer from addiction. Addiction is a complex disorder that can have psychological and physical components. But while psychological and physical addiction are often used interchangeably, there are several key differences between them.

Addiction comes in many forms, all falling under two basic types of addiction: physical and psychological/behavioral. Here’s your chance to learn a bit more about each addiction and how they affect an individual.

It isn’t always easy to tell if someone has an addiction to drugs or alcohol. Though if you suspect that a loved one may be addicted, your suspicions should be taken seriously.