Issues around drug taking, including addiction,

tolerance, physical and psychological dependency, withdrawal

Addiction

Addiction is a state where an individual feels a compelling need to consistently use a substance or engage in an activity despite its harmful consequences.
Physiological addiction refers to a state where the body has adjusted to the presence of a drug and it cannot function normally without the drug.
Psychological addiction, on the other hand, is characterised by mental desire or compulsion to use a substance or engage in an activity where no physical dependency exists.

Tolerance is a state of adaptation where exposure to a drug results in diminished effects over repeated uses.
Tolerance to a drug can develop rapidly with substances such as opioids and benzodiazepines.
There are two types of tolerance: pharmacodynamic tolerance (changes at the cellular level that reduce the drug’s effect) and pharmacokinetic tolerance (also called metabolic tolerance, where the body becomes more effective at eliminating the drug before it has an effect).

Physical dependency is a physical condition caused by chronic substance use, characterised by withdrawal symptoms when the substance is suddenly discontinued.
Symptoms of physical dependency can vary greatly, depending on the substance, but they may include nausea, pain, tremors, or changes in blood pressure and heart rate.
Factors that contribute to the severity of withdrawal include the kind of drug, duration of use, dosage frequency, and overall health of the individual.
Psychological dependency is a form of dependency where an individual’s emotional state is linked to the use of a substance or engagement in an activity that is psychologically reinforcing.
Psychological dependency often leads to substance cravings and feelings of restlessness or anxiety when the substance or activity is not available.

Withdrawal refers to the physical and psychological symptoms that occur after chronic use of a drug is reduced or stopped.
Withdrawal symptoms are typically the opposite of the effects of the substance.
The severity and duration of withdrawal is influenced by the type of drug, duration of use, dosage amount, as well as genetic factors.
Symptoms of withdrawal may include, but are not limited to, anxiety, restlessness, insomnia, and physical symptoms such as sweating, trembling, and nausea.
Management of withdrawal often requires medical supervision and may involve using medication to reduce symptoms and prevent complications.