Definition of Opioid Use Disorder
According to the American Society of Addiction Medicine, "addiction is a primary, chronic disease of brain reward, motivation, memory and related circuitry. Dysfunction in these circuits leads to characteristic biological, psychological, social and spiritual manifestations. This is reflected in an individual pathologically pursuing reward and/or relief by substance use and other behaviors. Addiction is characterized by inability to consistently abstain, impairment in behavioral control, craving, diminished recognition of significant problems with one’s behaviors and interpersonal relationships, and a dysfunctional emotional response. Like other chronic diseases, addiction often involves cycles of relapse and remission. Without treatment or engagement in recovery activities, addiction is progressive and can result in disability or premature death."
This chronic illness has a biological basis and does not indicate a moral failing or lifestyle choice.
According to the DSM-5 the diagnosis of Opioid Use Disorder can be applied to someone who uses opioid drugs and has at least two of the following symptoms within a 12 month period:
Opioid tolerance, dependence, and addiction are all manifestations of brain changes resulting from chronic opioid abuse. The opioid abuser’s struggle for recovery is in great part a struggle to overcome the effects of these changes. Medications such as methadone and buprenorphine act on the same brain structures and processes as addictive opioids, but with protective or normalizing effects. Despite the effectiveness of medications, they must be used in conjunction with appropriate behavioral health therapies.
We recognize both the biological basis of addiction and each person’s unique socioeconomic and cultural situation, and work to individualize treatment to each person. Our goal is to deliver compassionate, evidence-based care that improves quality of life and daily life functioning.
Pleasure derived from opioids’ activation of the brain’s natural reward system promotes continued drug use during the initial stages of opioid addiction. Subsequently, repeated exposure to opioid drugs induces the brain mechanisms of dependence, which leads to daily drug use to avert the unpleasant symptoms of drug withdrawal. Further prolonged use produces more long-lasting changes in the brain that may underlie the compulsive drug-seeking behavior and related adverse consequences that are the hallmarks of addiction.
Three important classes of opioid receptors:
1. μ receptor or Mu receptors: Three subtypes: μ1, μ2 and μ3 receptors. Present in the brainstem and the thalamus, activation of these receptors can result in pain relief, sedation and euphoria as well as respiratory depression, constipation and physical dependence.
2. κ receptor or kappa receptor: Present in the limbic system. Activation of this receptor causes pain relief, sedation, loss of breath and dependence.
3. δ receptor or delta: Widely distributed in the brain and also present in the spinal cord and digestive tract. Stimulation of this receptor leads to analgesic as well as antidepressant effects but may also cause respiratory depression.
Opioids target the brain's reward system by flooding the circuit with dopamine. Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, cognition, motivation, and feelings of pleasure. The over-stimulation of this system, which rewards our natural behaviors, produces the euphoric effects sought by people who misuse drugs and teaches them to repeat the behavior. Our brains are wired to ensure that we will repeat life-sustaining activities by associating those activities with pleasure or reward. Whenever this reward circuit is activated, the brain notes that something important is happening that needs to be remembered, and teaches us to do it again and again, without thinking about it. Because drugs of abuse stimulate the same circuit, we learn to abuse drugs in the same way.
One of the most widely prescribed medications, opiates and opioids (Oxycodone, Lortab, Percocet, and OxyContin) are opioid-based pain medications. Opiates are a derivative of opium which is also used to manufacture heroin and morphine and opioid are synthetic opiates. Opiates/opioids are successful in diminishing pain but are highly addictive, and the withdrawal symptoms of opioid addiction are very similar to the pain it was relieving. Opioids are some of the most commonly abused prescription pain medications today.
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