Physical dependency on drugs refers to the body's adaptation to a drug, where the body becomes dependent on the drug to function normally. Withdrawal symptoms occur when the drug is discontinued or the dosage is reduced. Physical dependency is typically associated with drugs that are habit-forming, such as opioids, benzodiazepines, and alcohol. Withdrawal symptoms can include nausea, vomiting, diarrhea, muscle cramps, seizures, and more.
Psychological dependency on drugs refers to a person's emotional or mental reliance on a drug. It is often characterized by cravings for the drug, obsessive thoughts about the drug, and the belief that the drug is necessary for a person to feel "normal" or to cope with stress or emotional issues. Psychological dependency is not necessarily associated with physical withdrawal symptoms, but it can be just as difficult to overcome as physical dependency.
Both physical and psychological dependency can occur simultaneously, and it can be difficult to distinguish between the two. In general, physical dependency tends to develop faster than psychological dependency, but psychological dependency can be just as strong and persistent, even after physical withdrawal symptoms have subsided.