Lecture 7 - Addiction & Substances Flashcards
What is a drug defined as?
Any substance that exerts an effect on the body or the mind (neurophysiological, behavioural, emotional, or cognitive).
What is one definition of addiction?
Behaviours involving compulsion, loss of control and continued patterns of abuse despite negative consequences.
What is the debate over habit and addiction?
Habit argues that it is a choice, as cravings are situational. Addiction, however, argues that control is impaired.
Why is there such a high comorbidity between substance-use and other disorders?
60% comorbidity. Due to overlapping genetic vulnerabilities/environmental triggers, similar brain region interaction, interaction effects, etc.
What do monozygotic twin studies demonstrate?
High concordance for a range of drugs (alcohol, cannabis, tobacco, etc.), suggesting a general genetic component to substance abuse.
What do theories of neural sensitization argue?
Users sensitize easily while others take longer -> learning process. Repeated administration amplifies response until it is sensitised (less of an effect) -> can be cross-sensitized (generalised to other substances).
What are the four clusters of addictive behaviours?
Intoxication: higher dopamine concentrations in limbic circuits and frontal lobe.
Craving: wanting or needing a substance (conditioning).
Compulsive use: continued use even with no pleasure.
Withdrawal: dysphoria (dissatisfaction), anhedonia (inability to feel pleasure) and irritability -> relapse.
Describe the process of dopamine levels following drug intake.
Molecules block dopamine transporters, halting the reuptake process of dopamine into other neurons. A large excess of dopamine builds up at the synapse and ‘overflows’, causing pleasure and euphoria.
Describe the five brain regions involved with drug taking.
Amygdala: immediate pleasure.
Hippocampus: remembers the experience.
PFC: directs attention to pleasurable stimuli.
Nucleus accumbens: pleasure centre, which continues the behaviour.
Reward system: reactivated when the behaviour is completed.
Describe how casual drug use becomes addiction.
People casually use the drug, then are conditioned (classically and instrumentally) to compulsively take the drug. This then becomes addiction over time.
Why are substance-use disorders difficult to treatment? (5)
No one-for-all treatment, as it needs to be readily available, intervenes in medical, psychological and social ways, issues with comorbidity, treatment cannot always be voluntary and issues of recovery.
