Addiction

Dual-process models

• suggests cognitive processes underlie addiction 

• Two Systems of Decision-Making

  • System 1: Fast, automatic, emotional (impulse to drink)

  • System 2 : Slow, deliberate, controlled (resisting drinking)

• Explains why people plan to limit drinking but fail when stressed or cued

Limitations of dual-process models

• Presented as a ‘battle’ between impulse and control

• Doesn’t explain why some choose risky behaviour even when fully informed

• Ignores how people might weight costs and benefits differently

• Doesn’t capture individual variability in decision making

• Doesn’t explain recovery from addiction- most people who are ‘addicted’ recover without treatment (Heyman, 2013).

• Low quality evidence of associations between cognitive substrates of impulse control and alcohol use (e.g. Baines & Jones, 2021).

Concurrent choice tasks

• Cognitive tasks in which participants make choices between a drug and a natural reinforcer (e.g. soft drinks or food) over a series of trials.

• Different designs may use points for rewards, pictures of rewards or consumption of rewards (Hogarth, 2020).

• All index goal-directed behaviour towards a particular substance.

• Increased choice for alcohol demonstrated when more severely, depressed, anxious and after negative mood induction.

• Making alcohol taste bad (devaluing) reduces choice for alcohol (Rose et al, 2018)

• are a common measure of value

Value based decision making 

• A ‘behavioural economics’ approach (based on costs vs. benefits)

• Drinking may reflect the high subjective value of alcohol (e.g. social reward> health risk)

• Decision to drink isn’t always impulsive it could be goal driven

• Value-based decision making explains:

  • Context-dependent drinking

  • Gradual behaviour change

  • Motivational shifts over time

Value based choice model of self control (Berkman et al, 2017)

• all choices are made by comparing the subjective value of available options and selecting the one with the highest overall value at that moment.

• Each possible action has its own subjective value, determined by how much weight the decision-maker assigns to each input from the left side.

• These values are compared and integrated via a process known as value-based evidence accumulation (a dynamic decision process).

• Once one option’s subjective value exceeds a decision threshold, that option is enacted

• So, the chosen action is simply the most valued option at that moment, not the result of suppressing an impulse.

Drif diffusion models (DMM) 

used to understand the underlying accumulation of evidence

Brief assessment of alcohol demand (BADD)

• a questionnaire measure asking participants how much money they would pay for substances

• a three item measure

• assesses three factors of  ‘demand’

  –Intensity- the maximum consumption at no cost

  –Omax- peak expenditure, how much someone is willing to spend on a substance

  –Breakpoint- The price at which use is suppressed

• HOWEVER, financially based  so can be affected by social-economic status/ how much disposable income people have

association between meaning in life and harmful drinking

• assessed whether this is mediated by increased self-control and reduced alcohol value

• A strong sense of meaning in life is significantly associated with higher Trait self-control. This high self-control, in turn, strongly reduces the likelihood of harmful drinking

• Having meaning in life is significantly, though modestly, associated with less value placed on alcohol

• The act of searching for meaning is significantly associated with lower Trait self-control. This deficit in self-control then contributes to higher harmful drinking. 

• searching for meaning is also significantly associated with a modest increase in the value placed on alcohol. This increased value strongly predicts higher harmful drinking 

• "Presence" acts as a protective factor (or "buffer") against harmful drinking by strengthening self-regulation and de-valuing alcohol.

• "Search" acts as a risk factor, potentially reflecting a state of distress or existential confusion that leads to poorer self-control and a greater inclination to seek comfort or value in alcohol.

Social influence and consumption of alcohol 

•Assessed the effect of environment (bar lab vs standard lab) and social influence (positive/negative appraisal) using confederates on alcohol value and alcohol consumption.

•Social influence only affected intensity with greater intensity following positive vs negative appraisal.

•There was also a sig main effect of social influence on alcohol consumed

•Direct effect of social influence condition on ad lib consumption (positive appraisal condition drink more)

•Indirect effect of social influence on ad lib alcohol consumption via intensity (partial mediation)

Cannabis study

• Test whether inputs (social company, location, effort) and momentary value predict:

  • Odds of cannabis use

  • Quantity used

• assessed using BAMD

• No association between social context or location and increased odds of using cannabis.

• Lower effort to obtain cannabis predicted increased odds of use.

• BAMD intensity was associated with increased odds of use

• Higher craving, positive mood, and intention to use, were associated with increased odds of using cannabis.

• No association between social context, location or effort, and quantity of cannabis consumed.

• BAMD intensity associated with higher quantity consumed,

• Higher craving, positive mood, and intention to use were associated with increased quantity of cannabis consumed.

evaluation of value based decision making 

• Some argue that the model assumed a level of rationality

  • But Berkman does argue that there is room for biases, subjective value and distortions (Berkman et al, 2017)

• Lack of focus on habit or compulsion.

  • But maybe value-based decisions ‘feel’ compulsive or habit like but aren’t

• Some may argue that VBDM is too simple and neglects the complexity of substance use (i.e. contextual factors). Proponents would argue that these are accounted for via ‘value inputs’

• Is it falsifiable?

• BUT can explain why most people recover from addiction. Which brain disease models that emphasise habit/compulsion can’t explain (Field et al, 2020).