Addictions and Substance Use Disorders

substance-induced disorders

• substance intoxication

  • Reversible and temporary condition due to the ingestion of a substance

  • Clinically significant behavioural or psychological changes

• substance withdrawal

  • Occurs when the amount of substance in the blood/tissue decreases suddenly after heavy use

  • Usually temporary, characteristic withdrawal symptoms depending on the substance

substance use disorder criteria

• Problematic pattern of substance use, leading to clinically significant impairment or distress, evidenced by at least two of the following:

  • 1) Substance often taken in larger amounts or over longer period than intended

  • 2) Persistent desire or unsuccessful efforts to cut down or control use

  • 3) Great deal of time spent in activities necessary to obtain the substance, use substance, or recover from its effects

  • 4) Craving, or strong desire or urge to use the substance

    • 1 to 4: impaired control over substance

  • 5) Recurrent substance use may result in a failure to fulfill
    major role obligations at work, school, or home

  • 6) Use is continued despite recognizing physical or
    psychological problems caused or exacerbated by the
    substance

  • 7) Important social, occupational, or recreational activities are
    given up or reduced because of substance use

    • 5 to 7: social impairment

  • 8) Recurrent use in situations in which it is physically hazardous

  • 9) Continue substance use despite knowledge of having a
    persistent or recurrent physical or psychological problem that
    is likely to have been caused or exacerbated by the substance

    • 8 to 9: risky use

  • 10) Tolerance

    • Need for markedly increased amounts of the substance to achieve intoxication or desired effect

    • Markedly diminished effect with continued use of the same amount of the substance

  • 11) Withdrawal

    • Characteristic withdrawal symptoms of the substance

    • The same or a closely related substance is taken to relieve or avoid withdrawal symptoms

      
      

substance use disorders

• Specifiers:

  • Early (3-12 months) remission

  • Sustained (>12 months) remission

  • Mild (2-3 symptoms), moderate (3-4), or severe (>5)

• The body and brain make changes to adapt to the effects of the drug

  • “Down-regulation” refers to reduced neurotransmitter production as the brain compensates for the presence of a
    substance

  • Eg: less dopamine is produced in the brain following regular/heavy cocaine use

  • Changes can involve the amount of neurotransmitters produced, the number of receptors on neurons, the degree of re-uptake of neurotransmitters to the transmitting neuron, or other changes

• When the drug is withdrawn, symptoms that were suppressed by
  the action of the substance are heightened

• Symptoms of dependence are often related to, or the opposite of,
  symptoms of intoxication of the substance

substance use disorders - etiology

• A few particularly addictive substances (cocaine, cigarettes,
  amphetamines) directly act on the dopamine system

  • Reward systems of the brain, also involved in learning

• Even for substances that do not have a direct effect on the
  dopaminergic system, changes can occur in this brain system and in related brain areas (dorsolateral prefrontal cortex, limbic system)

  • Substances of abuse are rewarding

• The “Rat Park” study in the 1970s suggested a social-materialist approach to understanding substance use

  • Rats that were provided with an enriched environment were less likely to self-administer morphine than rats in a “standard” lab environment

  • "The fundamental problem is we live in a screwed up world” – Bruce Alexander

substance use disorders - treatment

• Abstinence versus non-abstinence based treatment

• Residential treatment

• Antabuse (disulfiram) increases aversive effects of alcohol
  by blocking metabolism

• Replacement (eg: methadone)

• Support groups (AA etc), including for family members

• Harm-reduction rather than prohibition

  • North America (tobacco, alcohol, marijuana to some degree)

  • Netherlands (marijuana)

  • Portugal (other substances)

  • Safe injection sites

• The Ottawa Model

  • Asking about smoking status at each visit; advising all smokers to quit; providing assistance to quit; linking to follow-up counseling

• What does not work:

  • “Interventions”

  • D.A.R.E.

• behavioral therapy

  • Aversion therapy

  • Rewards and punishments for use or abstinence

  • Working to change life circumstances that the person is escaping

• cognitive therapy

  • Relapse prevention (awareness of signs of craving, making decisions to avoid people, places or things that were related to alcohol use)

  • Motivational interviewing (helping to facilitate the decision to quit or make changes to use)

alcohol use and abuse

• About 80% of Canadians consume alcohol, with the highest use in 18-24 year olds, singles, males

• Binge drinking is usually defined in research as five drinks or
  more on a single occasion

• Average age of first consumption of alcohol is 13, and earlier
  age is associated with more problems later in life

  • About a 15% reduction in adult alcohol use disorders for each year that a teenager defers drinking

• Some psychological effects of alcohol probably relate to expectations regarding its effect

• Short term effects:

  • At relatively low doses: euphoria, reduced inhibitions, confidence, sense of well-being, slower reaction time

  • At higher doses: blackouts, suppression of REM sleep, hangovers (cellular dehydration, nausea, headache)

• Long term effects:

  • moderate risk of dependence,

  • poor absorption and less consumption of nutrients can result in Alcohol Induced Persisting Dementia (Korsakoff's dementia)

• Fetal alcohol effects:

  • growth retardation, cognitive problems, behavioural problems
    (ADHD, ODD)

• etiology

  • Concordance of 26-77% in male monozygotic twins, 12-54% in dizygotic twins (lower concordance in females)

  • Genetically related risk factors include dysfunction in GABA receptors, greater ability to metabolize alcohol, lack of allergic reaction

anxiolytics

• Benzodiazepines, barbituates, “downers”

• Rarely the sole drug of abuse, often used together with opioids or alcohol

• Short term effects: mild euphoria, slurred speech, poor motor coordination, problems with judgment, attention, and memory

• Long term effects: depression, chronic fatigue, mood swings, paranoia

nicotine

• Peak prevalence in the 1960's, declining since then, most likely due to changing social norms, but increasing in many parts of the developing world

• 18% of Canadians consume tobacco products

• Highest prevalence in young adults, lower SES, indigenous people

• it is extremely fast to reach the brain (10 sec)

• short term effects: increase mood, alertness

• long term effects: Probably the highest real potential for dependence of any substance, and of course well established links to cancer and other health problems

amphetamines

• Ecstasy, speed, Ritalin, crystal meth

• Effects similar to natural occurring adrenalin (SNS arousal)

  • Short-term effects: Arousal, alertness, improved cognitive performance, exhilaration, extroverted behaviour, confidence, restlessness, anxiety

  • Long-term effects: Fatigue, sadness, social withdrawal, physical changes (weight loss, weakness, irregular heart rate)

  • High dependence potential

  • Rarely results in dependence when prescribed for ADHD

cocaine

• Short-term effects: Euphoria, energy, well-being, confidence, alertness, confusion, anxiety, aggression

• Long-term effects: mood swings, loss of interest, increased blood pressure, irregular heart rate

• Various methods of consumption have different speeds of effects and dependence potential

  • Freebasing (smoking crack cocaine) or injecting cocaine are particularly addictive (10-15 seconds from ingestion to brain)

opioids

• Natural opioids (morphine, codeine), semi- synthetic opioids (heroin, oxycodon), and synthetic opioids (methadone, Demerol)

• Short term effects: analgesia, euphoria, dulled sensations, appetite suppressant, respiratory depression

• Long term effects: pain sensitivity, dysphoria, anxiety, respiratory and pulmonary problems

• Opioids are not considered appropriate treatment for chronic pain in most cases

  • Rebound pain, even if the patient does not perceive a positive effect of the substance

• fentanyl

  • Fentanyl is a very potent synthetic opiate (50-100x as potent as morphine)

  • Prescription opioid use greatly increases the chance of opioid abuse

  • Health Canada has declared illicit use of fentanyl to be a public health crisis

    • Diluting the substance is very difficult to do accurately, and leads to uneven distribution across batches when done illicitly

cannabis

• Close to 50% lifetime prevalence of use

  • Estimated 5% prevalence of cannabis use disorders

• Short term effects: mild euphoria, relaxation, well-being, hallucinations, anxiety (sometimes)

• Long term effects: “Amotivational syndrome”, some evidence of mild cognitive impairment

• Low potential for addiction

• Tetrahydrocannabinol (THC) and Cannabidiol (CBD; generally fewer psychoactive effects)

hallucinogens

• Phencyclidine, PCP, ketamine, LSD, mescaline, magic mushrooms

• Short term effects: mood and setting congruent hallucinations, synesthesia, SNS arousal

• Long term effects: rarely, patients experience “hallucinogen persisting perception disorder”

• Low potential for dependence, withdrawal effects are very short lived if they occur at all

behavioral addictions

• Some evidence that brain activity in the dopaminergic system (reward processing) is similar in response to substances and other
  pleasurable activities

  • To the extent that the frontal-limbic reward system is responsible for dependence, other activities could potentially lead to addiction

• S*x, food, shopping, exercise, self-inflicted pain, spicy foods, Internet/social media use

• But the addiction potential of these behaviours is likely much much lower than that of most substances

• from a behavioral perspective, gambling and internet gaming are deliberately designed to have the maximum potential for repetitive behavior and addiction

  • variable ratio reinforcement schedule, with short latency between behavior and outcome —> amount of money spent, and the frequency of the gambling/gaming are not in and of themselves diagnostic

• Lifetime prevalence of gambling disorder is around 0.2% for women
  and 0.6% for men

• Literature on internet gaming is still new and has many confounds, so it is not an officially recognized disorder

  • Generalizing between societies, quality of research, poor definitions, probably often secondary to other mental illnesses