Lecture 1. Introduction Risk Behavior and Addiction in
Adolescence
Risk behaviors: Behaviors that pose a risk to a healthy physical, cognitive, psychosocial
development of adolescents
Contact with a substance → Experimenting with a substance → Integrated use → Excessive
use → Addicted use
We classify risk behaviors depending on..
-Characteristics of the particular substance or behavior. For Instance, smoking/vaping
versus gaming
-Cultural and societal norms. Example: alcohol use in Western versus Islamic Cultures
-Scientific knowledge. Example: knowledge on the risks of alcohol use for the cognitive
development of adolescents
● Early adolescence (aged 10 – 14): physical growth, sexual maturation,
psychosocial development, social identity formation
● Mid adolescence (aged 15 – 17): experimenting with (risk) behaviours, personal
identity formation
● Late adolescence (aged 18 – 24): practicing adult roles
Neurological development in adolescence
1. Strong grow in brain volume: increase in white matter (connections, myelinization), but
decrease in gray matter (nerve cells)
Pruning: if you don’t use it, you lose it!
Boys have more gray matter volume than girls. Frontal gray matter volume peaks around
puberty and then decreases in both girls and boys.
2. High plasticity and flexibility of the brain
3. Increase in white matter: communication between brain regions strongly improves
- Long term memory increases
- Capacity for abstract (critical) thinking and metacognition increases
,Why is there a peak in risk behavior during adolescence?
The speed of the development of two different brain regions differs
(1) The affective-motivational system (emotional brain) develops fast
(2) The control system (rational brain) develops slowly
1. The affective-motivational system. Emotional brain. Hot system.
- Nucleus accumbens: reward center.
- It’s overactive during early and mid adolescence.
- Adolescents experience stronger positive emotions than adults when they receive or
anticipate a reward. This process is enhanced by testosterone
- Bottom-up processes. Behavioral activation (BAS)
2. The control system. Rational brain. Cold system.
- Prefrontal cortex.
- The rational brain develops slowly (until about 25 years)
- Plays an important role in the development of executive functions:
● Risk estimation
● Monitoring long-term goals
● Inhibit the tendency to respond to (short-term) possibilities for reward (impulse
control, behavioral inhibition, self control)
- Top-down processes. Behavior inhibition (BIS)
The maturational imbalance model (Casey)
→ Increased risk-taking during adolescence is a result of an imbalance between reward
sensitivity (the affective- motivational system) and impulse control (control system)
Psychoactive substances are chemical substances that cross the blood-brain barrier and
affect the function of the central nervous system thereby altering perception, mood, or
consciousness (e.g., high/euphoria, relaxation)
-They often induce craving after (regular) use
-They often evoke loss of control after they have been used (regularly)
They differ in:
* Type and strength of the psychoactive effect (their effect)
* The degree to which they elicit craving and loss of control. (their addictiveness)
,For which substance is the risk highest to develop addiction after one has used the
substance?
How can we define addiction?
-Intensional: these definitions aim to describe a causal addiction process (see Sussman,
Table 1.2)
-Extensional: a classification of characteristics of an addiction (e.g. DSM-5)
, Two learning principles underlying the development of addiction:
1. Positive reinforcement occurs when the rate of a behavior increases because a desirable
experience (e.g., euphoria, relaxation) is resulting from the behavior.
2. Negative reinforcement occurs when the rate of a behavior increases because an
aversive experience is prevented from happening (e.g., withdrawal symptoms).
Drug use → Dopamine release in the nucleus accumbens → Reward
ok I
ok I→ Brain adaptation
ok (the sensitivity of the reward system decreases)
This decrease in the sensitivity of the brain reward system results from...
- Reduction in the number of dopamine receptors
- The existing dopamine receptors become less sensitive to dopamine
Resulting in...
1. Tolerance (needing a higherdoseofthedrugto have the same effect)
2. Withdrawal symptoms (during abstinence)
3. A reduced sensitivity to natural incentives
- Reduced sexual interest in cocaine users
Associative learning
1. Drug use is having rewarding outcomes (=positive reinforcement)
2. Stimuli related to drug use (drug-cues: bar, group of friends…) also get associated with its’
rewarding outcomes
3. Drug-cues themselves become salient because of its association with reward (incentive
salience)
It’s leading to 2 (implicit) cognitive biases
- Attentional bias: individuals with addictive behaviors develop an (automatic)
heightened attention towards drug-cues.
- Approach bias: individuals with addictive behaviors develop an automatic tendency to
approach, rather than avoid, drug-cues.
Adolescence
Risk behaviors: Behaviors that pose a risk to a healthy physical, cognitive, psychosocial
development of adolescents
Contact with a substance → Experimenting with a substance → Integrated use → Excessive
use → Addicted use
We classify risk behaviors depending on..
-Characteristics of the particular substance or behavior. For Instance, smoking/vaping
versus gaming
-Cultural and societal norms. Example: alcohol use in Western versus Islamic Cultures
-Scientific knowledge. Example: knowledge on the risks of alcohol use for the cognitive
development of adolescents
● Early adolescence (aged 10 – 14): physical growth, sexual maturation,
psychosocial development, social identity formation
● Mid adolescence (aged 15 – 17): experimenting with (risk) behaviours, personal
identity formation
● Late adolescence (aged 18 – 24): practicing adult roles
Neurological development in adolescence
1. Strong grow in brain volume: increase in white matter (connections, myelinization), but
decrease in gray matter (nerve cells)
Pruning: if you don’t use it, you lose it!
Boys have more gray matter volume than girls. Frontal gray matter volume peaks around
puberty and then decreases in both girls and boys.
2. High plasticity and flexibility of the brain
3. Increase in white matter: communication between brain regions strongly improves
- Long term memory increases
- Capacity for abstract (critical) thinking and metacognition increases
,Why is there a peak in risk behavior during adolescence?
The speed of the development of two different brain regions differs
(1) The affective-motivational system (emotional brain) develops fast
(2) The control system (rational brain) develops slowly
1. The affective-motivational system. Emotional brain. Hot system.
- Nucleus accumbens: reward center.
- It’s overactive during early and mid adolescence.
- Adolescents experience stronger positive emotions than adults when they receive or
anticipate a reward. This process is enhanced by testosterone
- Bottom-up processes. Behavioral activation (BAS)
2. The control system. Rational brain. Cold system.
- Prefrontal cortex.
- The rational brain develops slowly (until about 25 years)
- Plays an important role in the development of executive functions:
● Risk estimation
● Monitoring long-term goals
● Inhibit the tendency to respond to (short-term) possibilities for reward (impulse
control, behavioral inhibition, self control)
- Top-down processes. Behavior inhibition (BIS)
The maturational imbalance model (Casey)
→ Increased risk-taking during adolescence is a result of an imbalance between reward
sensitivity (the affective- motivational system) and impulse control (control system)
Psychoactive substances are chemical substances that cross the blood-brain barrier and
affect the function of the central nervous system thereby altering perception, mood, or
consciousness (e.g., high/euphoria, relaxation)
-They often induce craving after (regular) use
-They often evoke loss of control after they have been used (regularly)
They differ in:
* Type and strength of the psychoactive effect (their effect)
* The degree to which they elicit craving and loss of control. (their addictiveness)
,For which substance is the risk highest to develop addiction after one has used the
substance?
How can we define addiction?
-Intensional: these definitions aim to describe a causal addiction process (see Sussman,
Table 1.2)
-Extensional: a classification of characteristics of an addiction (e.g. DSM-5)
, Two learning principles underlying the development of addiction:
1. Positive reinforcement occurs when the rate of a behavior increases because a desirable
experience (e.g., euphoria, relaxation) is resulting from the behavior.
2. Negative reinforcement occurs when the rate of a behavior increases because an
aversive experience is prevented from happening (e.g., withdrawal symptoms).
Drug use → Dopamine release in the nucleus accumbens → Reward
ok I
ok I→ Brain adaptation
ok (the sensitivity of the reward system decreases)
This decrease in the sensitivity of the brain reward system results from...
- Reduction in the number of dopamine receptors
- The existing dopamine receptors become less sensitive to dopamine
Resulting in...
1. Tolerance (needing a higherdoseofthedrugto have the same effect)
2. Withdrawal symptoms (during abstinence)
3. A reduced sensitivity to natural incentives
- Reduced sexual interest in cocaine users
Associative learning
1. Drug use is having rewarding outcomes (=positive reinforcement)
2. Stimuli related to drug use (drug-cues: bar, group of friends…) also get associated with its’
rewarding outcomes
3. Drug-cues themselves become salient because of its association with reward (incentive
salience)
It’s leading to 2 (implicit) cognitive biases
- Attentional bias: individuals with addictive behaviors develop an (automatic)
heightened attention towards drug-cues.
- Approach bias: individuals with addictive behaviors develop an automatic tendency to
approach, rather than avoid, drug-cues.
