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Opioid dependency is a medical diagnosis characterized by an individual's inability to stop using opioids (morphine/heroin, codeine, oxycodone, hydrocodone, etc) even when objectively it is in his or her best interest to do so. In 1964 the WHO Expert Committee on Drug Dependence introduced "dependence" as “A cluster of physiological, behavioural and cognitive phenomena of variable intensity, in which the use of a psychoactive drug (or drugs) takes on a high priority. The necessary descriptive characteristics are preoccupation with a desire to obtain and take the drug and persistent drug-seeking behaviour. Determinants and problematic consequences of drug dependence may be biological, psychological or social, and usually interact”. The core concept of the WHO definition of “drug dependence” requires the presence of a strong desire or a sense of compulsion to take the drug; and the WHO and DSM-IV-TR clinical guidelines for a definite diagnosis of “dependence” require that three or more of the following six characteristic features be experienced or exhibited:
- 1. A strong desire or sense of compulsion to take the drug;
- 2. Difficulties in controlling drug-taking behaviour in terms of its onset, termination, or levels of use;
- 3. A physiological withdrawal state when drug use is stopped or reduced, as evidenced by: the characteristic withdrawal syndrome for the substance; or use of the same (or a closely related) substance with the intention of relieving or avoiding withdrawal symptoms;
- 4. Evidence of tolerance, such that increased doses of the drug are required in order to achieve effects originally produced by lower doses;
- 5. Progressive neglect of alternative pleasures or interests because of drug use, increased amount of time necessary to obtain or take the drug or to recover from its effects;
- 6. Persisting with drug use despite clear evidence of overtly harmful consequences, such as harm to the liver, depressive mood states or impairment of cognitive functioning.
The Walid-Robinson Opioid-Dependence (WROD) Questionnaire was designed based on these guidelines.
Some[who?] argue that this is a physical condition characterized by the dysregulation of the endogenous opioid receptor system, which results from chronic exposure to opiates during the period of administration. A recent study has shown that an increase in BDNF, brain-derived neurotrophic factor, in the ventral tegmental area (VTA) in rats can cause opiate-naive rats to begin displaying opiate-dependent behavior, including withdrawal and drug-seeking behavior. It has been known that when an opiate-naive person begins using opiates at levels inducing euphoria, this same increase in BDNF occurs.
Symptoms of withdrawal
Additional withdrawal symptoms include, but are not limited to, rhinitis (irritation and inflammation of the nose), lacrimation (tearing), severe fatigue, lack of motivation, moderate to severe and crushing depression, feelings of panic, sensations in the legs (and occasionally arms) causing kicking movements which disrupt sleep, chills, gooseflesh, headaches, anorexia (lack of appetite), benign fasciculation syndrome, mild or moderate tremors, and other adrenergic symptoms, severe aches and pains in muscles and perceivably bones, and weight loss in severe withdrawal.
Depending on the quantity, type, frequency, and duration of opioid use, the physical withdrawal symptoms last for as little as forty-eight to seventy-two hours (for short-acting opioids such as hydromorphone [Dilaudid] and oxycodone after short duration lower-dose use), and as long as thirty to sixty days for long-acting opioids such as buprenorphine and methadone, respectively, after extended high-dose use. When long acting opioids like methadone (Methadose, Physeptone) or buprenorphine (Suboxone [buprenorphine in a 4:1 ratio to naloxone] and Subutex [single-agent buprenorphine]) are used for an extended period, physical withdrawal symptoms can last up to six weeks. This initial withdrawal is characterized by the body regaining physical homeostasis.
- Varga-Perez H, Ting-A Kee R, Walton C, et al. (June 2009). "Ventral Tegmental Area BDNF Induces an Opiate-Dependent-Like Reward State in Naive Rats". Science 324 (5935): 1732–34. doi:10.1126/science.1168501.
- Laviolette SR, van der Kooy D (2009). "GABA(A) receptors in the ventral tegmental area control bidirectional reward signalling between dopaminergic and non-dopaminergic neural motivational systems.". Eur J Neurosci 13 (5): 1009. doi:10.1046/j.1460-9568.2001.01458.x. PMID 11264674.