Medical Model of Addiction

1. Medical Model of Addiction Dr. Morag Fisher

2. Conflict of Interest • None to disclose

3. Objectives • Definition of Addiction • Diagnostic Criteria • Contributing factors Neurobiology of addiction, tolerance & withdrawal

4. Addiction – CSAM definition • A primary, chronic disease characterized by impaired control over the use of a psychoactive substance or behaviour. • Clinically the manifestations occur along biological, psychological, social & spiritual dimensions. • Like other chronic diseases, it can be progressive, relapsing & fatal.

5. Addiction- CSAM definition 2 • Common features are change in mood, relief from negative emotions, provision of pleasure, • preoccupation with the use of substances or ritualistic behaviour; & • continued use of substances &/or engagement in behaviour despite adverse physical, psychological &/or social consequences.

6. DSM IV substance abuse • A maladaptive pattern of use leading to clinically significant distress – at least 1 criterion met within a 12 month period • Recurrent substance use resulting in a failure to fulfill major role obligations at work, school, or home • Recurrent substance use in situations in which it is physically hazardous • Recurrent substance-related legal problems • Continued substance use despite having persistent or recurrent social or interpersonal problems caused by the effects of substance use Has never met the criteria for Substance Dependence B.

7. Substance Dependence-DSM IV • A maladaptive pattern of substance use leading to clinically significant impairment or distress, as manifested by 3 or more of the following over a 12 month period: -Tolerance –diminished effect with use of the same amount, or increased amount used to achieve intoxication. -Withdrawal – characteristic withdrawal syndrome for the substance, or the same or closely related substance is taken to relieve or avoid withdrawal symptoms.

8. Substance Dependence-DSM IV • The substance was taken in larger amounts or for a longer period than was intended • There is a persistent desire or unsuccessful attempts to cut down • A great deal of time is spent in activities to procure the substance • Important activities are given up or reduced because of the substance • The substance use is continued despite knowledge of having a physical or psychological problem caused by or exacerbated by the substance use.

9. Anyone who uses a benzodiazepine or an opiate for several weeks can develop physical dependence.This is not sufficient criteria to diagnose addiction.

10. The Hallmark of Addiction • The 4 ‘C’s -Loss of Control of use of the substance -Compulsive use or Craving -Continued use despite adverse Consequences

11. ‘Pseudo – addiction’ • This is a term which is used to describe patient behaviors which may occur when pain is undertreated. They may appear to be drug focused & drug seeking , but the behaviors resolve when pain is effectively treated.

12. Contributing Factors : Opioid Risk Tool Family Hx of Substance Abuse Alcohol Illegal Drugs Rx Drugs Personal Hx of Substance Abuse Alcohol Illegal Drugs Rx Drugs History of Preadolescent Sexual Abuse Psychological Disease ADHD, OCD, Bipolar, Schizophrenia Depression Webster LR 2005

13. How do Opiates WorkPharmacology • Opiate receptors in the brain: several types - mu, delta, kappa - most important in addiction is the mu receptor • Analgesia & euphoria • Side effects: respiratory depression, sedation,nausea & constipation, low BP, pupils constrict Increased activity in the ventral tegmental area of the brain resulting in increased dopamine release in the nucleus accumbens = highly addictive

15. Human Molecular Genetics • 5 single nucleotide polymorphisms have been identified in the coding region of the human mu opioid gene • 3 of these lead to amino acid changes in the receptor • Some receptor variants have been associated with increased potency of activation of the receptor • Some have some association with increased vulnerability to dependence

16. Tolerance • The brain adapts to the constant presence of the opiate • It takes more drug to get the euphoria • Tolerance to respiratory depression doesn’t develop so quickly • Therefore there’s always risk of death from overdose

17. Withdrawal • Neurophysiological rebound in the organ systems on which opioids have their primary actions • CNS suppression --CNS over activity • Increased CNS noradrenergic hyperactivity primarily at the nucleus ceruleus

18. Opiate Withdrawal • Dilated pupils • Nausea, vomiting, cramps & diarrhea • Bone pain, headache • Chills, sweats, piloerection - “going cold turkey” • Anxiety, emotional lability, craving • Irritable & insomnia • NOT life-threatening (except risk of suicide) • NO seizures

19. Withdrawal • Worst at day 3-4 • Longer withdrawal for methadone • Improving by day 10 • Sweats can persist 3-4 weeks • Emotional lability will persist for weeks • Insomnia can last 6 months or more

20. Addiction Treatment Works • Many medical practitioners have a negative attitude towards dealing with addiction • Patients DO respond to brief interventions in the doctor’s office, to rehabilitation programs, & to methadone maintenance programs • Despite the research evidence our patients still have to deal with the stigma which is attached to the diagnosis of addiction & methadone treatment