Videos in this section deal with drug dependency. Drug addiction is characterized by a multitude of symptoms. Symptoms include, persisting to use despite negative consequences, financial problems, social problems, and physical problems due to use. Addicts differ depending on how much or how often they use. However, if all or even some of these symptoms are present, regardless of how much or little they use, drug addiction is most likely present. There are three main categories of drugs hallucinogens, opiates and stimulants. Some drugs fall into one or more of these categories. Addiction symptoms for every category are different though for all of them withdrawal symptoms occur when the substance is not being used.