Introduction: Addiction and Brain Reward and Anti-Reward Pathways – free full-text article /PMC4549070/ – Aug 2011
This is a long and detailed article explaining at length how pain and addiction manifest in neurological processes in various areas of the brain.
It also contradicts the belief that opioids cause addiction, which has motivated the anti-opioid crusaders to make life a hell on earth for pain patients. (see Pain Patients Left to Suffer in ‘Hell on Earth)
Can One Induce Addiction
by Long-Term Treatment of Pain with Opiates?
Far too many physicians and other healthcare professionals have uncritically accepted the false allegation that opiate addiction can be induced by medically appropriate long-term treatment of pain with opiates.
This leads to medical malpractice and the ethically unacceptable undertreatment of pain in millions of suffering patients.
Equally unacceptably, this misconception permeates the law-enforcement, judicial, and legislative branches of government – with many egregious consequences.
It also permeates ordinary society, causing many pain patients to refuse medically appropriate (indeed, often essential) treatment of pain – with often horrible consequences for quality of life.
The truth of the matter is that, although some chronic pain patients are at risk for addiction, they are a very small percentage of the total number of chronic pain patients.
Reliable evidence exists to support the contention that appropriate medical treatment of pain with opiates does not incur a risk of addiction in the vast majority of pain patients. First, chronic pain inhibits opiate-seeking behavior in animal models.
Second, chronic pain inhibits opiate-enhanced dopamine in the ventral tegmental area-nucleus accumbens reward/relapse neural circuitry .
Third, chronic pain inhibits reward signaling through the ventral tegmental area-nucleus accumbens reward circuitry, as assessed using the electrical brain-stimulation reward animal model.
Fourth, chronic pain inhibits the development of opiate-induced physical dependence.
I explained how this works in a previous post how our pain “uses up” both our endorphins and the extra opioids we take as medication: Opioids + Pain != Euphoria.
This explains why I can take extremely variable doses of opioids for my extremely variable pain: my highest daily dose is up to three times more than my lowest daily dose.
After a period of unusually intense pain and high opioid doses, I can drop down to much lower doses without any withdrawal symptoms when my pain eases again. I’ve always wondered how that’s possible, and this article explains it.
These preclinical animal model and neurobiological data – together with an impressive corpus of human clinical data – has prompted the World Health Organization to issue the following guideline on the treatment of chronic pain –
“When opioids are used – even at heroic doses – in the appropriate medical control of chronic pain, addiction and drug abuse are not a major concern”.
The article covers much more territory in addition to the excerpts above:
The Natural Progression of the Disease of Addiction
The disease of addiction is characterized by progressive stages. It always starts with occasional reward-driven use, which then progresses to steady (albeit non-addictive) reward-driven use. Reward-driven use progresses to habit-driven use, and habit-driven use progresses to compulsive use
Addiction and Physical Dependence – Different Phenomena and Different Brain Substrates
It is very important to realize that addiction and physical dependence are different phenomena with different underlying brain substrates.
Physical dependence results from the development of pharmacological tolerance, and manifests itself upon abrupt discontinuation of drug administration (or administration of an antagonist drug).
Addiction is a chronic progressively deteriorating disease characterized by compulsive drug use in the presence of harm to the addict and to the addict’s life.
Addiction is commonly described as the “Disease of the 5 Cs” –
Continued Compulsive drug use despite injurious Consequences, coupled with loss of Control and persistent drug Craving.
Many drugs (including, but not limited to, antihypertensives, cardiac medications, and asthma medications) produce pronounced physical dependence but are not addictive.
Some drugs (e.g., cocaine) are highly addicting but produce little or no physical dependence.
Persistent Drug Craving and Relapse – The Real Clinical Problem in Addiction
it is extremely difficult to overcome the persistent drug cravings that the abstinent addict is left with after achieving (often with great difficulty) abstinence.
This is why acute “detoxification” programs are almost invariably clinical failures in treating drug addiction.
Indeed, the failure rate is so high that physicians running such programs may be reasonably said to be engaging in medical malpractice.
Perhaps that’s why most “recovery programs” aren’t run by doctors: they know they’d be sued for calling abstinence (the 12-step approach) an appropriate medical treatment for addiction.
The Disentanglement of Important Addiction-Related Phenomena
a number of important phenomena are often confused, even among medical and other professionals who deal routinely with drug addiction and with patients impacted by it. It is important to disentangle these phenomena.
- First, abusive drug-taking behavior is initially reward-driven (the drug-induced “high”), and is directly referable to drug-induced activation of the ventral tegmental area-nucleus accumbens reward circuitry.
- Second, abusive drug-seeking and drug-taking behavior becomes, with time, habit-driven rather than reward-driven. This transition arguably defines the onset of addictive drug-seeking behavior,
- Third, addiction and physical dependence are different phenomena
- Fourth, opiate- or cannabinoid-induced analgesia are distinct phenomena – having nothing to do with opiate-induced or cannabinoid-induced addictive drug-taking behavior.