Withdrawal can refer to any sort of separation, but is most commonly used to describe the group of symptoms that occurs upon the abrupt discontinuation/separation or a decrease in dosage of the intake of medications and recreational drugs (including alcohol). In order to experience the symptoms of withdrawal, one must have first developed a physical/mental dependence (often referred to as chemical dependency). This happens after consuming one or more of these substances for a certain period of time, which is both dose dependent and varies based upon the drug consumed. For example, prolonged use of an anti-depressant is most likely to cause a much different reaction when discontinued than the repeated use of an opioid, such as heroin. In fact, the route of administration, whether intravenous, intramuscular, oral or otherwise, can also play a role in determining the severity of withdrawal symptoms. There are different stages of withdrawal as well. Generally, a person will start to feel worse and worse, hit a plateau, and then the symptoms begin to dissipate. However, withdrawal from certain drugs (benzodiazepines, alcohol) can be fatal and therefore the abrupt discontinuation of any type of drug is not recommended. The term "cold turkey" is used to describe the sudden cessation use of a substance and the ensuing physiologic manifestations.