Lecture Notes Risk Behavior and Addiction | UU | 2026/27

Notes Risk Behavior and Addiction in Adolescence

Inhoudsopgave
L1 – INTRODUCTION RISK BEHAVIOR AND ADDICTION IN ADOLESCENCE ...........................................2
L2 - SUBSTANCE USE PREVENTION ......................................................................................... 11
L3 – PEER INFLUENCE AND RISK BEHAVIOR IN ADOLESCENCE ........................................................ 16
L4 – INTERNATIONAL TEEN TRENDS IN SUBSTANCE USE ................................................................ 23
L5 – THE ROLE OF PARENTS IN THE PREVENTION OF RISK BEHAVIOR AND ADDICTION............................ 26
L6 – INDIVIDUAL VULNERABILITY FOR RISK BEHAVIOR AND ADDICTION ............................................. 32
L7 – NEUROBIOLOGICAL PROCESSES AND BEHAVIORAL MECHANISMS OF ADDICTION .......................... 36
L8 – ADDICTION AND TREATMENT/RECOVERY ................................................................................. 41




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,L1 – Introduction Risk Behavior and Addiction in Adolescence
Risk behavior = Behaviors that pose a risk to a healthy physical, cognitive, psychosocial
development of adolescents.
Substance use à (e.g., smoking/vaping, alcohol use, cannabis use, use of illicit drugs
(e.g., XTC and other party/designer drugs). (Mainly thinking about substance use when
referring to risk behavior).
Other risk behaviors à (e.g., (online) gambling, gaming, social media use), these can
develop into risk behaviors.

How does addiction/substance use develop:

1. Contact with a substance (friend smoking and oEering you)
2. Experimenting with a substance (curiosity, substance creates feelings/social
rewards)
3. Integrated use (regular user because of rewards)
4. Excessive use (regular, daily smoker, high doses)
5. Addicted use

What we tent to see as risk behavior depends on:

• Characteristics of the particular substance or behavior (how quick smoking
can become an addiction (fase 1 is already risky) vs gaming (many levels of how
much, healthy people who game (fase 4 may be risky)).
• Cultural and societal norms (western society accepts drinking one glass of
alcohol a day (not risky) vs. Islamic cultures think already having 1 glass is
regarded risky).
• Advances in scientific knowledge (knowledge of risks of alcohol use for brain)

Predictors of Risk Behavior (COM-B model)

All behaviors develop as a result of 3
things: opportunity, capability and
motivation.
à come back in the behavior change
wheel (Lecture 8).




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,Developments during adolescence
Adolescence is the period between 10 and 24 years old.

• Early adolescence (aged 10 – 14): physical growth, sexual maturation
(development diEers between boys and girls, boys are generally 2 years older
when this happens) psychosocial development (peers become more important,
especially your position. Parents become less important), social identity
formation (find out who you are, how you are seen by others, basis for other
identity developmental tasks). à young people are vulnerable for disapproval by
peers, feeling rejected, feeling accepted by peers is very important.
• Mid adolescence (aged 15 – 17): experimenting with (risk) behaviors, personal
identity formation (forms based on social identity, if this is negative (feeling left
out) makes it much more diEicult to form a positive personal identity (how do I
see myself). In this period you want to be unique, you don’t want to be like
everybody else (contrast with social identity formation).
• Late adolescence (aged 18 – 24): practicing adult roles, preparing for adult roles.

Neurological development in adolescence

1. Strong growth in brain volume (when children start adolescence)
a. Decrease in grey matter (nerve cells, outer layer)(not all parts)
b. Increase in white matter (connections, communication between regions)




Boys have more grey matter then girls (does not say anything about
intelligence). Girls peak earlier in the grey matter then boys.
c. Parts of the brain that are hardly used, they are lost (= pruning, if you don’t
use a certain part of your brain, you lose it.)
2. High plasticity and flexibility of the brain, things are not set in stone (if social
skills are not used they become less, but they do not disappear forever. However,
it is a very important fase in your life.
3. Increase in white matter: communication between brain regions strongly
improves:


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, a. Long term memory increases
b. Capacity for abstract (critical) thinking and metacognition increases.

The development of risk behavior shows an inverted U-shaped curve:




à The speed of the development of 2 diEerent brain regions diEers:

• The aXective motivational system (emotional brain) develops fast, pretty deep
in the brain.
• The control system (rational brain) develops slowly, more on the outer layer.




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