Nicotine addiction and treatment Flashcards
What characterises tobacco dependence?
It is a chronic, relapsing condition, sustained by nicotine
What are the three types of treatment for tobacco dependence?
- Medication
- Behavioural support
- Electronic cigarettes
What is the smoking prevalence?
> 1 billion people smoke cigarettes
> Smoking rates have declined in UK, USA, Australia and New Zealand to less than 20%
> Some groups have not benefitted from tobacco control initiatives
What is the smoking prevalence in people with Depression and anxiety?
32%
What is the smoking prevalence in people with psychosis?
62%
What is the smoking prevalence among substance users?
80%
When does tobacco dependence usually start?
Usually in childhood
What happens physiologically when you smoke?
> Nicotine rapidly absorbed through lungs
> Stimulates nicotine acetylcholine receptors in VTA
> Iincreased firing and release of dopamine in VTA -> increased amount in nucleus accumbens
= Direct Reward pathway
-> “teaching signal” to get more
What are the rewarding properties of nicotine?
> Stimulant which improves attention and mood
> BUT tolerance diminishes these cognitive improvements
What is the mechanism of nicotine tolerance?
Negatively reinforcing:
- brain adapts and has to be cooped up in order not to experience irritability and loss of concentration
What is the half-life of nicotine and what is its consequence?
Nicotine half-life = 2 hours
-> after short periods of not smoking -> experience of withdrawal symptoms
=> brain teaches smoker to smoke in presence of withdrawal symptoms
How are cigarettes engineered to get nicotine to the brain?
Ammonia + Cocoa:
- products and chemicals added to tobacco plant as it’s growing or after harvest
- some chemicals are dangerous and become more toxic once tobacco is burned
What is the action of ammonia in cigarettes?
Speeds up transport of nicotine form lungs to brain
best used for cleaning toilets
What is the action of cocoa in cigarettes?
- Enhances taste
AND - It’s a bronchodilator: widens airways
-> more tobacco smoke in your lungs -> more nicotine to brain (reward pathway…)
What composes tobacco smoke?
> Ammonia
> Cocoa
> 500 gases: carbon monoxide, ammonia, formaldehyde, hydrogen cyanide
> 3,500 particulates: nicotine, tobacco nitrosamines, polycyclic hydrocarbons
How does nicotine differ from other ingredients of tobacco smoke?
> Nicotine: main cause of addiction and dependence
> Other ingredients (toxins, carcinogens): main cause of high mortality rate
Why does the nicotine delivery system matter?
Because nicotine is the main cause of addiction and dependence (not mortality)
-> switching to a less harmful form of nicotine delivery system is a step away from tobacco smoking
AND a step towards better health
What is the average duration of most withdrawal symptoms?
- Top-up needed every 2 hours
- Peak 24-48 hours after quitting
- Subside within 2-4 weeks
What does the plasma nicotine concentration graph of Benowitz (2010) tell us?
First cigarettes of the day are the most pleasurable and satisfying
- in neutral zone: no pleasure/arousal and no withdrawal (abstinence) symptoms
What are the physical health damages of smoking?
> Harms heart and affects blood circulation
> Harms brain and can cause strokes
> Lung related illnesses
- bronchitis, emphysema, cancer, chronic obstruction pulmonary disease
> Reproductive health damages
> Dental damages
> Bone damages
=> 50% of smokers will die of smoking related disease
What characterises chronic obstruction pulmonary disease?
Progressive and debilitating condition
How does smoking contribute to poor mental health?
> More severe symptoms of psychosis
> Higher rates of depression, anxiety
-> longer time in hospital
> Higher doses of medication needed
> Can cause poverty
> Exploitation and stigma
> Unhealthy coping skills (reach cigarette at times of stress)
How does smoking lead to a need of higher doses of medication?
Tar in tobacco smoke speeds up metabolism of some medication
-> lower levels of drug in the blood
