Addictive Behaviours

1. Addictive Behaviours Addictive Behaviours

2. Addictions • A physical dependency to a substance results in withdrawal symptoms in its absence. • Dependency: persistent intake of drug even if there is known harm • Tolerance: increasing doses are needed over time to produce same effect • decrease in the sensitivity/number of receptors for that drug • decreased sensitivity of intracellular mechanism responsible for drug’s effects • Withdrawal: symptoms opposite to those produced by the drug when it is no longer taken Addictive Behaviours

3. Prevalence Varies by substance (Report on Smoking in Canada 2001, Canadian Addiction Survey 2004): • Nicotine: 21.7% • Heavy alcohol consumption (5+ drinks more than once a week): 6.2% • Cannabis: 14.5% • Cocaine: 1.9% • Other “heavier” drugs: <1% • Food, shopping, pornography, etc: ??? Addictive Behaviours

4. Case Study • Leslie Ann, a 16-year-old female addicted to crack cocaine and alcohol, was the mother of a 5-month-old infant son. According to hospital reports, within an hour of the child’s birth Leslie Ann had left the obstetrics ward and did not return. It was later learned that she had been looking for a “hit.” Following this episode, the infant’s prenatal exposure to crack was documented and Child Protection Services subsequently placed the infant in foster care. At presentation, Leslie Ann was attending a drug rehabilitation program as a prerequisite for regaining custody of the child. Addictive Behaviours

5. Case Study • Leslie Ann had started using cocaine as a teenager. She soon became addicted, left school and engaged in petty criminal activities, as well as prostitution, in an effort to raise money for her habit. She attempted unsuccessfully to stop using drugs and alcohol when she learned of her pregnancy. During the pregnancy, she did not avail herself of prenatal care and first saw an obstetrician when she was in labor. Addictive Behaviours

6. Case Study • Leslie Ann grew up in a deteriorating inner city neighborhood, the fourth of her mother’s six children by three different men. She denied physical or sexual abuse, but claimed that neither her mother, father, stepfather or her mother’s subsequent boyfriends had paid sufficient attention to her or her siblings. • She was raised partly by her oldest sister and partly by a neighbor down the hall. At age 14, she began experimenting with alcohol and drugs-marijuana, cocaine, and heroin-but soon stopped using heroin because she was afraid of contracting AIDS. Addictive Behaviours

7. Case Study • At that time, she lived occasionally in her mother’s apartment and most of the time on the street or with a friend. “I didn’t go to school. . . just sat around and got high,” she said candidly. • After she began using drugs, Leslie Ann met Terence, an 18 year-old drug dealer. She was attracted to him because he “didn’t tell me not to use drugs or try to change who I was,” she explained to the therapist. • Terence had a nice apartment and, at least initially, treated Leslie Ann well. Addictive Behaviours

8. Case Study • Approximately 3 months after meeting Terence, she became pregnant. The pregnancy was “definitely unplanned,” Leslie Ann said and her first impulse was to have an abortion. She procrastinated, however, until she was too far advanced for the procedure. Thus, the decision to have the baby was made by default. She reported that she did not enjoy being pregnant. The changes in her physical appearance distressed her and she experienced unpleasant physical symptoms, including morning sickness, back pains, and the exacerbation of several allergies. Addictive Behaviours

9. Case Study • Although Leslie Ann insisted she had tried to stay away from drugs during the pregnancy, she admitted that she was not successful. The drugs made her “feel better,” she said, especially when she became depressed about losing her shape. She reported that she had no fantasies about the baby while she was pregnant. • Instead,she focused on her own discomfort and looked forward to having the baby simply because the pregnancy would end. Labor and delivery were relatively easy, although Kevin was examined immediately because he was small for his gestational age. Addictive Behaviours

10. Case Study • Immediately after the birth, Leslie Ann said she became confused. “I needed to get high and didn’t think about the baby,” she noted as an explanation for leaving the hospital. After purchasing and smoking some crack, Leslie Ann did not return to the hospital because she thought there would be no point in doing so. Addictive Behaviours

11. Addictions: DSM-IV Addiction (termed substance dependence by the American Psychiatric Association) is defined as a maladaptive pattern of substance use leading to clinically significant impairment or distress, as manifested by three (or more) of the following, occurring any time in the same 12-month period: 1. Tolerance, as defined by either of the following: (a) A need for markedly increased amounts of the substance to achieve intoxication or the desired effect or (b) Markedly diminished effect with continued use of the same amount of the substance. Addictive Behaviours

12. Addictions: DSM-IV 2. Withdrawal, as manifested by either of the following: (a) The characteristic withdrawal syndrome for the substance or (b) The same (or closely related) substance is taken to relieve or avoid withdrawal symptoms. 3. The substance is often taken in larger amounts or over a longer period than intended. 4. There is a persistent desire or unsuccessful efforts to cut down or control substance use. Addictive Behaviours

13. Addictions: DSM-IV 5. A great deal of time is spent in activities necessary to obtain the substance, use the substance, or recover from its effects. 6. Important social, occupational, or recreational activities are given up or reduced because of substance use. 7. The substance use is continued despite knowledge of having a persistent physical or psychological problem that is likely to have been caused or exacerbated by the substance. • Substance dependence may have with physiologic dependence or no physiologic based on evidence of tolerance or withdrawal. Addictive Behaviours

14. Addictions: DSM-IV Substance abuse is defined as a maladaptive pattern of substance use leading to clinically significant impairment or distress as manifested by one (or more) of the following, occurring within a 12-month period: 1. Recurrent substance use resulting in a failure to fulfill major role obligations at work, school, or home (such as repeated absences or poor work performance related to substance use; substance-related absences, suspensions, or expulsions from school; or neglect of children or household). 2. Recurrent substance use in situations in which it is physically hazardous (such as driving an automobile or operating a machine when impaired by substance use) Addictive Behaviours

15. Addictions: DSM-IV 3. Recurrent substance-related legal problems (such as arrests for substance related disorderly conduct) 4. Continued substance use despite having persistent or recurrent social or interpersonal problems caused or exacerbated by the effects of the substance (for example, arguments with spouse about consequences of intoxication and physical fights). Addictive Behaviours

16. How do people become addicted? • Positive reinforcement • increases the likelihood that it will occur • e.g. inject heroin -> rush followed by calm -> increased likelihood of another injection • usually works better for fast acting rather than slow acting drugs. Addictive Behaviours

17. How do people become addicted? 2. Negative reinforcement: behaviour is followed by a reduction of an aversive stimulus • e.g. depressed - > drink -> forget about depression (increases social behaviour) - > drink again • e.g. depressed -> shop for hours -> forget about depression -> shop again • May partially account for withdrawal symptoms Addictive Behaviours

18. How do people become addicted? • Big Problem: Many addictions are resistant to extinction. • Also, simple learning models don’t account for destructive and harmful behaviour of addicts • Blatant disregard for the law, social norms, personal hygiene and health Addictive Behaviours

19. How do people become addicted? • Dependence and withdrawal are not the main obstacles to curing addiction. • Risk of relapse is high: Cravings for the drug persist for years or decades after dependence/ withdrawal symptoms subside. • Not a simple case of reinforcement, but of some long-term, pathological learning resulting in maladaptive behaviour. Addictive Behaviours

20. Mesocortical Pathway • Different drugs target different pathways, psychological effects vary. • But, the mesocortical pathway is activated for all addictive behaviours: • Ventral tegmental area • Nucleus accumbens (ventral striatum) • Amygdala (and hippocampus) • Orbitofrontal/cingulate cortex • All addictive behaviour increases synaptic dopamine in the NA Addictive Behaviours

21. Addictive Behaviours

22. Mesocortical Pathway • Dopaminergic pathway associated with rewards for survival-related behaviours • Hunger, thirst, sexual arousal • Strong affective component • Addictive drugs mimic the effects of natural rewards • Motivation for drugs may supercede those of natural stimuli because drugs produce far greater levels of dopamine. • Behave as if drugs are required for survival. Addictive Behaviours

23. The Reward Prediction-Error Hypothesis • Mesocortical pathway is not responsible for pleasure signal per se • Rather, neurons along this pathway fire in the presence of cues that predict the onset of the reward (Shultz and colleagues). • DA neurons fire (phasic burst) prior to intake of drug, or to unexpected reward • Cells are silent (no tonic activity) if reward is withheld • “Craving” or “wanting” pathway: responds to cues to desire • Anticipation or prediction of reward Addictive Behaviours

24. The Reward Prediction-Error Hypothesis • Prefrontal areas responsible for drug-related goal selection • Complex sequence of action planning • Pathological narrowing of goals • Behaviour modified to provide maximum exposure to cues for reward • “Foraging” for drugs • May supercede regular feeding, or law-abiding behaviours Addictive Behaviours

25. The Reward Prediction-Error Hypothesis Temporal and other memory areas • DA neurons innervating multiple targets, project widely throughout the forebrain • May account for context-rich, location specificity of addictions (Shalev et al., 2002). • Rats show more addictive behaviours when in the environment where drug was initially administered. Addictive Behaviours

26. Cocaine • Powerful addictive stimulant • Two forms: • Hydrochloride salt: powdered form which dissolves in water and can be taken intravenously or intranasally. • “Crack” or “Freebase”: a compound that has not been neutralized by an acid to make the hydrochloride salt. • The freebase form of cocaine is smoked. Addictive Behaviours

27. Cocaine • Dopamine agonist that directly binds to the dopamine transporter in the VTA and NA (among other areas) • Blocks the normal recycling process, resulting in a buildup of dopamine in the synapse, which contributes to the pleasurable effects of cocaine. • Results in a drastic increase of DA from the nucleus accumbens • Buildup of dopamine in the synapse contributes to the pleasurable effects of cocaine. Addictive Behaviours

28. Cocaine: Short Term Effects • Affect: euphoric, energetic, talkative, and mentally alert, especially to the sensations of sight, sound, and touch. • Decreases the need for food and sleep. • Physiological constricted blood vessels, dilated pupils, and increased temperature, heart rate, and blood pressure. • Large amounts may also lead to bizarre, erratic, and violent behavior, including tremors, vertigo, muscle twitches, paranoia Addictive Behaviours

29. Cocaine: Long Term Effects • Psychological: Increasing irritability, restlessness, and paranoia. • full-blown paranoid psychosis, in which the individual loses touch with reality and experiences auditory hallucinations. • Physiological: cardiovascular effects, (heart rhythm and heart attacks), respiratory failure • Neurological effects: strokes, seizures, and headaches • Gastrointestinal effects: abdominal pain and nausea. • Combining cocaine and alcohol is highly toxic, and exacerbates long term effects. Most fatalities result from this mixture. Addictive Behaviours