Problem 4 1.4
Psychoactive drugs
Psychoactive drugs- drugs that influence subjective experience and behaviour by
acting on the nervous system
Agonist- heightened working of neurotransmitters by blocking their reuptake. The
neurotransmitters bind to receptors as they stay in the synapse and keep stimulating
the post synaptic neuron
Antagonist- block receptors so block the effect of certain neurotransmitters
Affinity- whether the drug binds to the receptor
Efficacy- tendency of a drug to activate the receptor
Reasons for addiction
Drug sensitization- becoming more sensitive to a drug
Drug tolerance- less sensitivity to drugs through regular exposure, this weakens their
effect. You can become tolerant to one effect to the drug e.g. euphoria but more
sensitive to another effect e.g. tremors
Cross tolerance- tolerance to other drugs by regular use of one drug
Conditioned tolerance- effects of drugs when taking them in the same environment
(interceptive and exteroceptive stimuli)
- Conditional-compensatory response- if you are in an unfamiliar surrounding you
are more likely to overdose as your body isn’t ‘expecting’ the drug. The
environment counter effects the drug
- Conditioned-withdrawal response- one experiences more withdrawal symptoms
when the drug is taken in the usual environment as they are ‘expecting’ to feel a
certain way
Contingent drug tolerance- tolerant to the effects that have been continuously
experienced, not tolerant to the effects that have not been experienced
Functional tolerance- the reactivity of sites is reduced, decreasing the binding
efficacy or diminishing the effect
Metabolic tolerance- when there is a change in the amount of the drug in the side of
action. The drug gets broken down before it can have an effect
Theories of addiction
Physical dependence theories of addiction
- The physical dependence of the drug traps addicts in vicious cycles of drug taking
and withdrawal symptoms – fear of withdrawal symptoms
- Detoxification- not successful as a treatment as some drugs don’t have strong
withdrawal symptoms yet people still relapse
Positive-incentive theories of addiction
- The primary motivation is the positive effect of the drug
- believe the hedonic effect is what causes addiction
- hedonic value- amount of pleasure that is actually experienced
incentive sensation theory
- the positive incentive value of addictive drugs increases with drug use
Psychoactive drugs
Psychoactive drugs- drugs that influence subjective experience and behaviour by
acting on the nervous system
Agonist- heightened working of neurotransmitters by blocking their reuptake. The
neurotransmitters bind to receptors as they stay in the synapse and keep stimulating
the post synaptic neuron
Antagonist- block receptors so block the effect of certain neurotransmitters
Affinity- whether the drug binds to the receptor
Efficacy- tendency of a drug to activate the receptor
Reasons for addiction
Drug sensitization- becoming more sensitive to a drug
Drug tolerance- less sensitivity to drugs through regular exposure, this weakens their
effect. You can become tolerant to one effect to the drug e.g. euphoria but more
sensitive to another effect e.g. tremors
Cross tolerance- tolerance to other drugs by regular use of one drug
Conditioned tolerance- effects of drugs when taking them in the same environment
(interceptive and exteroceptive stimuli)
- Conditional-compensatory response- if you are in an unfamiliar surrounding you
are more likely to overdose as your body isn’t ‘expecting’ the drug. The
environment counter effects the drug
- Conditioned-withdrawal response- one experiences more withdrawal symptoms
when the drug is taken in the usual environment as they are ‘expecting’ to feel a
certain way
Contingent drug tolerance- tolerant to the effects that have been continuously
experienced, not tolerant to the effects that have not been experienced
Functional tolerance- the reactivity of sites is reduced, decreasing the binding
efficacy or diminishing the effect
Metabolic tolerance- when there is a change in the amount of the drug in the side of
action. The drug gets broken down before it can have an effect
Theories of addiction
Physical dependence theories of addiction
- The physical dependence of the drug traps addicts in vicious cycles of drug taking
and withdrawal symptoms – fear of withdrawal symptoms
- Detoxification- not successful as a treatment as some drugs don’t have strong
withdrawal symptoms yet people still relapse
Positive-incentive theories of addiction
- The primary motivation is the positive effect of the drug
- believe the hedonic effect is what causes addiction
- hedonic value- amount of pleasure that is actually experienced
incentive sensation theory
- the positive incentive value of addictive drugs increases with drug use
