Substance Use Disorders DSM IV has two separate categories of substance use disorders A Substance Dependence What we typically think of as addiction Involves physiological dependence withdrawal symptoms Use is frequent interferes with functioning but they can t stop using B Substance Abuse Less severe than dependence Use is typically sporadic but causes functional impairment Lifetime Prevalence of substance related diagnoses Nicotine 24 Alcohol 14 20 male 8 female Illicit drugs 6 Effects of Alcohol It affects 3 major neurotransmitters glutamate GABA dopamine Reduces rate of neural firing in frontal cortex cerebellum glutamate GABA Increases rate of dopamine activity especially in brain s reward centers Effects vary by blood alcohol concentration 05 slight buzz decreased inhibition judgment 10 moderate motor incoordination slowed reactions 20 decidedly intoxicated severe motor sensory deficits 35 surgical anaesthesia 40 breathing impaired coma 50 death from organ failure Alcohol implicated in 50 of traffic fatalities and violent crimes Korsakoff s syndrome vitamin B1 deficiency Liver cirrhosis Brain damage atrophy over time in frontal cortex hippocampus cerebellum Fetal brain damage even with 1 5 drinks per week in pregnancy Depression co morbidity 25 Alcohol Dependence Subtypes Type I versus Type II Type I socially anxious drinking to self medicate Type II antisocial violate social norms What causes alcohol abuse dependence A Biological factors 1 Alcohol more reinforcing for some individuals Dopamine receptors D2 genetics childhood abuse neglect When addicted low dopamine response to everyday highs 2 Toxic metabolites acetaldehyde more punishing for some 3 AA Model alcoholism as uncontrollable disease B Sociocultural factors cultures vary dramatically in alcohol use problems C Personality factors two risks antisocial or neurotic trait anxious Treatments for Alcohol Use Problems 10 of those with problems enter treatment per year 50 dropout rate 30 of completers recovered at 1 year follow up abstinent Among alcohol abusers high spontaneous recovery rate Pharmacological interventions Naltrexone Vivitrol injection Antabuse Prometa targets GABA Alcohol drug vaccines Alcoholics Anonymous AA Little systematic research they don t release records Available data 25 50 success at 1 year probably about same as CBT Other Important Points 1 Diagnosis of abuse dependence requires functional impairment 2 Thus occasional binge drinkers aka college students usually don t meet diagnostic criteria 3 Most alcohol abusers don t progress to alcohol dependence majority of collegeage abusers no longer diagnosable in 30s 4 AA model Alcoholism disease generally applicable to dependence not abuse AA 12 step program heavily spiritual higher power Drugs of Abuse Addiction Every culture has had an array of drugs substances used to induce changes in mood thought and behavior Major classes of addictive drugs Hallucinogens psychedelics Stimulants Narcotics opioids Depressants anti anxiety Addictive drugs target brain s reward centers nucleus accumbens hypothalamus VTA A Hallucinogens marijuana ecstasy LSD shrooms PCP 1 Marijuana THC targets opioid receptors in brain s reward centers anandamide bliss also affects frontal cortex activity hippocampus cerebellum cognitive effects short term memory attention mental flexibility motor amotivational syndrome absorption with present reduced achievement fairly low addictive potential little tolerance moderate withdrawal Marijuana versus Alcohol a Potential for lethal overdose Alcohol b Long term brain damage Alcohol c Greater addiction potential Alcohol d Damage to developing fetus Alcohol e Driving impairment Alcohol f Violence trigger Alcohol g Damage to major organs Alcohol 2 Ecstasy MDMA hallucinogen and stimulant Originally called empathy oxytocin boost attachment Enhanced sensory awareness serotonin sensory integration Neurotoxic effects damage to serotonin using neurons temperaturedependent 3 LSD Lysergic acid diethylamide Blocks some serotonin activity 5HT2A agonist increased dopamine Altered sensory perception synaesthesia seeing sounds feeling colors etc B Stimulants amphetamine cocaine meth Stimulates release of dopamine blocks reuptake Energizing short term increase in frontal cortex activity long term frontal damage Amphetamine psychosis Potently addictive about 1 in 6 who try Relatively poor long term prognosis in stimulant dependence Nicotine stimulant and depressant extraordinarily addictive Smoking cessation about 15 success rate over one year C Narcotics Codeine Morphine Heroin Directly target brain s reward centers opioid system Also reduce pain physical and emotional At high doses turns off respiratory control centers in brain Naltrexone particularly effective for narcotic addiction