Substance use disorders

Substance use disorder

Problem related to using psychoactive substances

Substances that produce change in thinking, feeling, behaving or psychological functioning

Use VS intoxication

Use - occasional ingestion

Intoxication - effects of substance on CNS lead to reversible psych of behavioural changes.

Abuse vs dependence

Abuse - interference with life

Dependence - physiological (withdrawal and/or tolerance) and psychological (drug-seeking behaviours).

Tolerance

• Increased amount of substance necessary for the same high

• Reduced effect with the same amount of substance

Withdrawal

• Substance-specific syndrome due to cessation or reduction of heavy, prolonged substance use

• Syndrome causes clinically significant distress or impairment in important areas of functioning.

DSM-5-TR clinical definition for substance related and addictive disorders

A pattern of substance use leading to significant impairment or distress as indicated by 2 of the following in a 12 month period:

1. Substance taken in large amounts over a longer period than intended.

2. Persistent desire or unsuccessful efforts to cut down or control substance use.

3. Craving, strong desire to use the substance.

4. Important social, occupational or recreational activities are impaired, given up or reduced because of substance use.

5. Recurrent substance use in situations in which it is physically hazardous

6. Tolerance

7. Withdrawal

Substance use specifiers

• Mild: 2-3 symptoms

• Moderate: 4-5 symptoms

• Severe: 6+ symptoms

• Course specifiers:

  • Early remission (no symptoms for 3-12 months

  • Sustained remission (no symptoms for 12+ months)

  • Controlled environment (ex. rehab or prison)

EX. opioid use disorder, severe, in early remission

Sobriety

• If a person is not currently in a substance use disorder, their history of SUD is relevant because of risk of relapse.

• If someone is substance-free for life, they are still in sustained remission.

Prevalence

• Overall: 22% have criteria for a substance use disorder at some point in their live (~6 million people).

• Alcohol use disorder: 18% meet criteria at some point.

• Cannabis: 7%

• Nicotine: 10-15%

Behavioural addictions

• Gambling disorder is the only behavioural addiction.

• Similarities

  • Both activate reward centre in brain

  • Intense cravings or urges

  • Tolerance and withdrawal

  • Impairment

• Differences

  • Intoxication vs thrill

  • Withdrawal

    • Psychological vs physiological

  • Treatment

    • Behavioural vs medical

Causal factors

1. Euphoria

   • Drugs flood the brain with dopamine and activate the reward system

   • Intense pleasure to reinforce repeated use

2. Tolerance (need more for the same effect)

   • Brain adapts by reducing dopamine production and receptor sensitivity

   • Users increase dose to feel same high

3. Withdrawal

   • Dopamine drops, triggers anxiety, cravings and physical discomfort.

   • Severity varies (Ex. opioids > pain, alcohol > seizures, nicotine > irritability)

Genetic and biological factors

• Genetics

  • Most research on alcoholism

  • One alcoholic parent = higher risk

  • Genetic differences in alcohol metabolism

    • More efficient metabolism of alcohol without unpleasant effects can lead to greater risk of AUD due to more drinking + greater tolerance.

Psychological factors

• Learning factors play an important role in the development of substance use.

  • Observing caregivers/family use substances (normalizing)

  • Social reinforcement

    • Inhibits negative affect/anxiety in social settings, peer encouragement

  • Opponent-process theory

    • Brain attempts to balance out high with crash

    • Less intense high and more intense crash

    • Need more drug for high and makeup for crash

Cultural factors

• Cultural attitudes towards substance use

  • Higher rates of substance use in university populations

  • Lower rates of SUD among religious groups

  • Argentina, Chile, Canada, Japan, US, New Zealand make up less than 20% of the world pop but consume 80% alcohol.

Environmental factors

• Stress and coping - chronic stress and trauma can lead to self-medication

  • High stress jobs = higher SUD rate

• Economic and housing instability - poverty and unemployment increase reliance on substances as an escape.

  • Homelessness strongly correlates with alcohol and opioids.

  • Lack of access to other coping mechanisms, healthcare.

• Availability: easier access = higher use (liquor stores, dispensaries, prescriptions)

  • Regions with high alcohol and drug availability report increased misuse.

Biological treatment

• Agonist substitution

  • Safe drug with similar chemical composition as abused drug

    • Ex. methadone for heroin, nicotine gum or patch

• Antagonistic treatment

  • Drugs that block the positive effects of substances

  • Naltrexone for opiate and alcohol problems.

• Aversive treatment

  • Drugs that make use of substance unpleasant

    • Ex. antabuse for alcoholism, silver nitrate for nicotine.

• Efficacy:

  • Not effective treatments when used alone

  • More effective with psychological treatment.

Psychosocial treatments

• Harm reduction vs complete abstinence as goal:

  • Best treatment tailored to situations.

• Inpatient vs outpatient

  • Little difference in data

• Community support programs

  • Alcoholics anonymous and related groups

Prevention programs

• Individual and group therapy

  • Motivational interviewing (MI): helps individuals resolve ambivalence by increasing change talk, enhancing self-efficacy

• Aversion therapy

• Contingency management

  • Rewards for abstinence

• Community reinforcement

• Relapse prevention

Social intervention

• Address healthcare, social support and recreational needs to reduce reliance on substance

  • Affordable mental health and addiction treatment

  • Safe access to prescription medications

• Social inclusion and recreation

  • Expand housing-first programs to stabilize vulnerable populations

  • Increase public funding for sports, arts and community programs

  • Provide safe social spaces for youth and at-risk populations.