<unk>  can develop as a result of self-medication. Scoring systems have been derived to assess the likelihood of opiate addiction in chronic pain patients. Prescription<unk> s are the source of nearly half of misused<unk> s and the majority of these are initiated for trauma or surgery pain management. Further to this, healthcare practitioners have long been aware that despite the effective use of<unk> s for managing pain, the empirical evidence that supports the use of<unk> s long term is minimal. In addition to this, many studies that involved patients with chronic pain have failed to show any sustained improvement in their pain or ability to function with long term<unk>  use. According to position papers on the treatment of<unk>  dependence published by the United Nations Office on Drugs and Crime and the World Health Organization, care providers should not treat<unk>  as the result of a weak moral character or will but as a medical condition. Some evidence suggests the possibility that<unk> s occur due to genetic or other chemical mechanisms which may be difficult to identify or change, such as dysregulation of brain circuitry involving reward and volition. However, the exact mechanisms involved are unclear, leading to debate regarding the influence of biology and free will.
Opioid use disorder
Alcoholism
Stimulant use disorder
Benzodiazepine use disorder
Cannabis use disorder
Benzodiazepine dependence
Amphetamine dependence
Cocaine dependence