Psych - Substance Abuse + Addiction Flashcards
What drugs can cause substance addiction?
• Alcohol • Nicotine • Cannabis • Stimulants – Amphetamine – Cocaine • Crack – Ecstasy • Opioids (prescribed, OTC) – Heroin, fentanyl – DF118 • Ketamine • Solvents • GHB, GBL • Benzodiazepines • Psychedelics – LSD, Magic mushrooms • Nitrous oxide • Khat • ‘Novel psychoactive substances’ – ~950 synthetic (UNODC); – new: ~1/wk – Categories: • Depressant, stimulant, hallucinogenic. cannabinoid
Why do people take recreational drugs?
- reduce anxiety
- get high
- boredom
- stay awake
- to fit in
- rebel
- escapism
- like it
- to get to sleep
- why not
- feel better
- everyone does
- curious
What is positive reinforcement?
action taken to gain a positive state
What are examples of positive reinforcement that fuel addiction?
- escapism
- get high
- stay awake
- like it
What is negative reinforcement?
action taken to overcome adverse states
What are examples of negative reinforcement that fuel addiction?
- boredom
- to get to sleep
- reduce anxiety
- feel better
What is the course of addiction or drug abuse? *
• "LIKE" : Experimental/‘recreational’ use, causes no/limited difficulties - (majority of population) • "WANT" : Increasingly regular use (fewer people) • "NEED" : Spiralling, dependence (smaller number)
What is the definition of harmful substance use?
Actual damage should have been caused to the mental or physical health of the user in the absence of diagnosis of dependence syndrome
What is the progression from “like” to “want” to “need called?
neuroadaptations
What is the prevalence of alcohol dependence?
– 595, 000 estimated prevalence
– 103,471 in treatment
– approx. 82% of adults in need of specialist treatment for alcohol not receiving it.
What is the prevalence of opiate dependence?
– 257,476 estimated prevalence
– 170,032 in treatment
– ~46% of adults in need of specialist treatment for opiates not receiving it
– Death rates rising from opiates and from cocaine
What is the definition of addiction?
compulsive drug use despite harmful consequences, characterized by an inability to stop using a drug; failure to meet work, social, or family obligations; and, (depending on the drug) tolerance and withdrawal
What is dependence?
refers to a physical adaptation to a substance
– Tolerance/withdrawal
so can be dependent and not addicted
What are some examples of behavioural addictions?
– internet gaming disorder
– gambling disorder
Why was gambling reclassified as a behavioural addiction from ‘impulse control disorder’ previously?
Many similarities in aetiology, neurobiology and treatment
approaches, as well as comorbidity, with substance dependence
What is hazardous substance use?
likely to cause harm if it continues at this level
Phil drinks four pints of Stella most evenings. Says his drinking doesn’t cause problems. What issue may he have?
Hazardous Use:
– quantity + frequency is too high
Jenny drinks a bottle of wine most evenings, more at the weekends. Occasionally misses work
because of hangovers. What issue may she have?
Harmful Use:
– negative consequences
– Physical, Psychological, Social impact
– Eg Missing work due to hangovers
Tom drinks cider first thing each morning to stop himself shaking. Regards drink as a medicine,
believes he wouldn’t get by without it. Doesn’t tend to get drunk. What is the issue?
Dependence / Addiction:
– Tolerance and morning drinking to relieve
– withdrawal are signs of dependence.
Katie broke her ankle 6 months ago which healed well and is back to playing football. Is still taking her
opioid painkillers which are on repeat prescription. Is there an issue?
Likely biologically dependent as has been taking opioids for many months; no evidence of taking more than is
prescribed (ie suggesting ‘abuse’) however need to ask if this
is the case and why it is on repeat – has it just happened through error/lack of review or has she requested it?
Samson Broke his ankle 3 months ago and says he is still in pain. Is still taking his opioid painkillers and often
requests his prescription earlier. Is there an issue?
Likely biologically dependent as has been taking opioids
for many months; is taking more than is prescribed so need to
ask why – for pain or to deal with withdrawal or ‘likes how it makes him feel’. Consider harmful use, ask about any other addiction behaviours to clarify if addicted
Adam broke his ankle 4 months ago and is still taking his opioid painkillers, often requests his prescription earlier, is also taking up to 12 Neurofen plus tablets/day, uses alcohol and cannabis to help him sleep and has not gone back to work.
Likely biologically dependent as has been taking opioids
for many months; is taking more than is prescribed and buying
extra as well as using other drugs – highly likely to be addicted
How does brain entry affect addiction?
faster brain entry = more “rush” and more addiction
What elements are involved in alcohol / drug interactions?
– social / environmental factors
– drug factors
– personal factors e.g. genetic, personality traits
What is the brain pathway for drug use to addiction?
– pre-existing vulnerbaility + family history + age
– drug exposure + compensatory neuroadaptations to maintain brain function
– recovery sustained or cycles of remission and relapse
What is the brain pathway for alcohol use to addiction?
– pre-existing vulnerbaility + family history + age
– drug exposure + compensatory neuroadaptations to maintain brain function
– why drink?, tolerance, withdrawal
Why are we compelled to drink alcohol?
– Alcohol alters the balance between brain’s inhibitory and excitatory system
How does acute alcohol affect the excitatory system?
– blocks the NMDA receptors, blocking the system
– impaired memory (alcoholic blackouts)
How does acute alcohol affect the inhibitory system?
– boosts inhibitory system
e. g. Anxiolysis
e. g. Sedation
How does chronic alcohol exposure effect the excitatory system?
up regulation of the excitatory system
How does chronic alcohol exposure affect the inhibitory system?
– reduced function in inhibitory system - tolerance
– GABA-A receptors switch in subunits to make them less sensitive to alcohol
How is the absence of alcohol affect the excitatory + inhibitory system?
– complete withdrawal with no balance in GABA and glutamate
– up regulation of excitatory system
– NMDA receptor: increase in Ca2+ = toxic
– leads to hyper-excitability (seizures) + cell death (atrophy)
- reduced function in the inhibitory system
How is the withdrawal state from alcohol treated?
– Benzodiazepines (boosts GABA function + reduces glutamate)
– Acamprosate (helps people remain abstinent + reduces NMDA function)
–Naltrexone – opioid antagonist – to block heroin use in opioid addicts and to modulate reward system in alcoholism
What are some common examples of benzodiazepines?
– lorazepam
– diazepam
What are the 3 main models of addiction?
– reward deficiency (positive reinforcement)
– impulsivity / compulsivity
– overcoming adverse state e.g. withdrawal, anxiety (negative reinforcement)
How does the dopamine relate to addiction?
natural rewards (e.g. sex, food) and certain drugs (e.g. opioids) increases levels of dopamine in the Ventral Striatum this dopamine pathway = "pleasure-reward-motivation" pathway
How do drugs such as cocaine, amphetamine, opiates, etc. relate to dopamine?
– cocaine + amphetamine block dopamine reuptake from he synapses
– amphetamine enhances release of DA
– other drugs of abuse eg alcohol, opiates, nicotine increase dopamine neuron firing in VTA (ventral segmental area)
What is addiction often conceptualised as?
reward deficient state
Who are vulnerable to addiction?
adolescents are vulnerable to problematic drug use due to reward deficient states
What make abstinent addicts more likely to relapse physiologically?
more blunted response in brain to anticipation of rewards
What are the different stages of addiction?
– binge / intoxication
– withdrawal / negative affect
– preoccupation / anticipation (craving)
What regions of the brain are involved in the “binge / intoxication” stage?
– Dorsal Striatum
– Thalamus
What regions of the brain are involved in the “withdrawal / negative effect” stage?
brain stem + hypothalamus
What regions of the Brian are involved in the “preoccupation / anticipation / craving” stage?
prefrontal cortex
hippocampus
Basolateral amygdala
insula
How does positive or negative reinforcement change as addiction progresses?
– positive reinforcement decreases after a small rise
– negative reinforcement increases as positive reinforcement decreases, and it continues to increase
What stage + regions of the brain are target for treatment?
– withdrawal + negative emotional states
– reward system : reduced dopamine and mu opioid function + stress system : increased activity in many including kappa opioid (dynorphin), noradrenaline (arousal system) CRF (stress) should be targeted
– dysregulation in amygdala is key
How is addiction in the brain studied and assessed?
through fMRI + stimulation
What does the amygdala’s response look like for abstinent polydrug addicts and abstinent alcoholics?
– nothing different in alcoholics
– left amygdala has heightened brain response for polydrug addicts
How does the brain transition when drug use changes from voluntary to habitual?
• prefrontal to striatal control
over drug taking
– i.e. prefrontal ‘top-down’ control is diminished with greater striatal reward drive
• ventral (limbic or emotional) to dorsal (habit) striatum.
– big role for hippocampus in the craving aspect
How is neurocircuitry assessed in inhibitory control?
– fMRI + go, no-go task
– assessing putamen and inferior frontal gyrus
What is the relationship between brain response + alcohol abstinence?
Greater response in frontal pole/inferior frontal gyrus during inhibiting response in abstinent alcoholics:
greater response associated with longer abstinence
