R&A – Lectures and literature
Lecture 1A – Introduction risk behaviour and addiction in adolescence
Questions that will be addressed:
1. Which (neurological) developments take place during adolescence?
2. Why is there a peak in risk behaviours during adolescence?
3. How do we define risk behaviour, psycho-active substances (drugs) and addiction?
4. Which learning principles play a role in the development of addiction?
5. Which neurobiological mechanism plays a role the development of tolerance and withdrawal
symptoms?
How do we define risk behaviour?
Risk behaviour are behaviours that pose a risk to a healthy physical, cognitive, psychosocial development of
adolescents. Substance use is a form of risk behaviour, but there are also other risk behaviours as well (gaming
etc.), which can lead to addiction.
General developmental process:
1. Contact with a substance.
2. Experimenting with a substance.
3. Integrated use.
4. Excessive use.
5. Addicted use.
What we tend to regard as risk behaviour depends on characteristics of the particular substance or behaviour
(e.g., smoking vs. gaming), cultural and societal norms, and scientific knowledge.
Which (neuro logical) developments take place during adolescence?
Adolescence can be divided into three categories. Early adolescence (10-13) is characterized by physical
growth, sexual maturation, psychosocial development, and social identity formation. Mid adolescence (14-18)
is characterized by experimenting with (risk) behaviours, and personal identity formation. Late adolescence
(19-24) is characterized by practicing adult roles.
During adolescence, neurological development takes place. There is a strong grow in brain volume. The white
matter increases (connection), which strongly improves the communication between brain regions. The long-
term memory increases and the capacity for abstract thinking/metacognition increases. The grey matter
decreases (nerve cells), which is called pruning. Frontal grey matter volume peaks around puberty. During
adolescence, there is a high plasticity of the brain.
Why is there a peak in risk behaviour during adolescence?
The speed of the development of two different brain regions differs:
1. The affective-motivational system (emotional brain) develops fast.
a. Nucleus accumbens (reward centre, affective-motivational system, emotional brain).
b. This system (reward centre) is overactive in early and mid-adolescence. Adolescents experience
stronger positive emotions than adults when they receive or anticipate a reward. This process
is enhanced by testosterone.
2. The control system (rational brain) develops slowly (until about 25 years).
a. Prefrontal cortex (control system, rational brain).
b. The rational brain plays an important role in the development of executive functions.
i. Risk estimation.
, ii. Monitoring long-term goals.
iii. Inhibit the tendency to respond to (short-term) possibilities for reward (impulse control,
behavioural inhibition, and self-control).
The maturational imbalance model:
1. Increased risk during adolescence is a result of an imbalance between
motivational bottom-up versus controlling top-down processes (high
reward sensitivity vs. immature impulse control).
What are psycho-active substances (drugs)?
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).
Other characteristics of psychoactive substances are that they often induce craving after (regular) use, and that
they often evoke loss of control after they have been used (regularly).
Psychoactive substances differ in type and strength of the psychoactive effect, and the
degree to which they elicit craving and loss of control. Nicotine is the most addictive
after using the substance ones, followed by heroin, cocaine, alcohol, and cannabis.
How do we define addiction?
Sussman (2017) differentiates between intentional and extensional definitions of addiction. Intentional
addiction definitions aim to describe a causal addiction process. Extensional addiction definitions are a
classification of characteristics of an addiction.
Substance use disorder (DSM-5):
1. Recurrent use over the last 12 months and meeting at least two of more of the following criteria.
a. Loss of control.
b. Social and other impairments.
c. Continuation despite knowledge of risky use.
d. Pharmacological effects (tolerance and withdrawal).
Two learning principles
Positive reinforcement occurs when the rate of a behaviour
increases because a desirable event (e.g., euphoria, relaxation) is
resulting from the behaviour.
Negative reinforcement occurs when the rate of a behaviour
increases because an aversive event is prevented from happening
(e.g., prevention of withdrawal symptoms).
Sussman (2017) – A general introduction to the concept of addiction and addictive effects
Substance addiction pertains to repetitive intake of a drug or food, whereas behavioural addiction pertains
to engaging in types of behaviours repetitively which are not directly taken into the body such as gambling or
sex. Both result in clinically significant impairment. Until recently, science only focused on addiction in the
sense of misuse of drugs that lead to physiological withdrawal symptoms. Researchers considered drugs which
cross the blood-brain barrier, and exogenous ligands or endogenous ligand functions (naturally occurring
neurotransmitter). Behavioural addictions alter endogenous ligand functions.
Obtaining a measurable description of a scientific concept such as addiction is useful to be able to make
inferences regarding how the concept is related to other concepts, and subsequently how the concept can guide
the development of useful application. The currently available definitions of addiction are not mutually
exclusive. Their boundaries are fuzzy. There are many recurrent, addictive patterns of behaviour that lead to
clinically significant impairment. The concept of addiction may apply broadly, but it is not trivial.
, The historical records depict increasing engagement in certain behaviour and reduction of alternative
behaviour. The word addiction has evolved from referring to binding a person to something to being more or
less a brain disease. Addiction to tobacco has a brief public history. Alcohol misuse, on the other hand, has been
noted throughout written history. Furthermore, the initial use of opium was described as divine enjoyment.
Medication used to treat opium misuse often contained opium themselves. Replacement medications that did
not contain opiate led to new problematic cocaine use. Marijuana also has a history of misuse. Contradictory,
there is no ancient history regarding food addiction. Historical literature presents descriptions of gambling and
sex addictions. Behavioural addictions have been studied empirically since the 1980s and are also referred to as
process addictions. Many behaviours that now refer to addictions were considered examples of vice, that is,
behaviours which are pleasurable, popular, possibly voluntary, and wicked.
There are two conceptions of addiction. An intensional definition of addiction pertains to causal or process
model type statements of addictions. They describe at minimum an addictive behavioural process, and at
maximum an etiology (causal story). An extensional definition of addiction provides a taxonomy of addiction
elements, which subsequently might be organized into a (more) intensional theory-based perspective (more
descriptive rather than etiologic). An alternative conceptualization when considering elements/components of
an addiction is that of family resemblances.
Physiological and psychological dependence (intensional)
The physiological and psychological dependence definition of addiction states that an addiction is a
prolonged engagement in addictive behaviour that results in its continued performance being necessary for
physiological and psychological equilibrium.
Tolerance, withdrawal, and craving are hallmark criteria of a dependence definition of addiction. Tolerance
refers to the need to engage in the behaviour at a relatively greater level than in the past to achieve previous
levels of appetitive effects. As tolerance increases, one likely spends more time locating and engaging in the
addiction. Withdrawal is an abstinence syndrome, which involves intense physical disturbance in the case of
some types of drug abuse. They vary across drugs of abuse. Behavioural addictions likewise exert withdrawal-
like symptoms. Craving refers to an intense desire to engage in a specific act. This intense desire reoccurs, is
compelling, and one often gives in to this desire. Craving might be considered part of the withdrawal syndrome
in a dependence model of addiction.
While many drug and non-drug addiction do not appear to produce obvious physical dependence, they do
create a subjective need for increased involvement in the behaviour to achieve satiation.
Impulsive obsessive/compulsive behaviour (intensional)
This definition of addiction pertains to engaging in the behaviour due to a building up of tension which is
released, resulting in pleasure or relief. What occurs is another building up of tension or craving for pleasure
again (positive reinforcement). Alternatively, when the building up of tension doesn’t result in pleasure but in
relief of anxiety, it leads to obsessions which produce anxiety and stress leading to a craving for relief again
(compulsion, negative reinforcement). Withdrawal (negative factor) leads to engagement in the addictive
behaviour. It is plausible that both processes operate in the same person.
Compulsions involve spontaneous desires to act a particular way, a subjective sense of feeling temporarily
out of control, psychological conflict pertaining to the imprudent behaviour, settling for less to achieve the same
ends, and a disregard for negative consequences. Arguably, obsessive-compulsive disorder (OCD) and
addictions may be overlapping constructs. However, many researchers use the term compulsion more narrowly,
defining it as a simple but intense urge to do something (only one feature of addiction). OCD-related behaviours
are defined as an intense ego-dystonic urge to engage in a simple, repetitive activity, to remove anxiety.
Conversely, an addiction involves the attempt to achieve some desired appetitive effect and satiation through
engagement in some behaviour (more complex behaviours).
Self-medication (intensional)
This definition pertains to relief from disordered emotions and sense of self-preservation through engaging
in addictive behaviour (e.g., reaction to trauma). The emphasis is on where a person engages in the behaviour
because the person feels sick and wants to feel well. Different behaviours (drugs) will relieve different negative
emotions (e.g., anger).
, Self-regulation (intensional)
In a self-regulation model, the present state of being cues attempt to reach a standard at which point satiation
is achieved, until the present state is no longer at the desired standard state. In this sense, people engage in
addictive behaviour in order to achieve an immediate temporary sense of comfort.
The BAS-BIS model, behavioural approach system and the behavioural inhibition, affects individual
differences in behavioural responses to cues for reward. These interdependent systems influence whether an
individual is likely to withdraw from or avoid situations that involve novel or threatening cues or whether a
person is likely to engage in novel or risky behaviour in response to cue for reward. An active BAS (mediated
by dopamine) is linked to more impulsive-type behaviours. An active BIS (mediated by the septo-hippocampal
system) is linked to inhibiting behaviour. Persons with difficulty in emotional self-regulation may be prone to
engage in addictive behaviours in order to achieve an immediate temporary sense of comfort. They are more
likely to utilize the BAS which is not working in sync with the BIS.
The incentive-sensitization theory focuses on the influence of neural adaption to addictive behaviours and
addictive behaviour-conditioned stimuli as the underlying mechanism perpetuating the addictive behaviours.
This theory differentiates neural processes involved in motivational mechanisms or incentive salience to
addictive behaviour cues (wanting) and the neural substrates of pleasurable effects (liking). A progressive
dysregulation of neural substrates occurs through repeated engagement in the behaviour, which, in turn, is
associated with an increase in behavioural sensitization contributing to addicts’ wanting the behaviour becoming
disproportionate to the pleasure derived from the behaviour. Through repeated engagement in the behaviour,
behaviour-associated stimuli that acquire incentive salience through neural representation (motivational
wanting) become motivational magnets, able to grab the addict’s attention. Adaptations in the wanting are
affected by the pharmacological effects of drugs, alterations in endogenous ligand transmissions, or associative
learning.
Yet another explanation comes from the notion of allostasis. According to this notion, addictive behaviour
leads to dopamine opponent-process counteradaptation (reduced dopamine and activation of brain stress
systems) that masks the effects of the addictive behaviour. To increase dopamine availability and initially
control feelings of anxiety or stress, the addictive behaviour may be repeated again and again. New set points
of homeostasis may then be established.
Addiction entrenchment (intensional)
In this model, one has an over-attachment to a drug, object, or activity (excessive appetite). Intrinsic and
extrinsic incentives addiction-promoting cognitive beliefs and expectancies drive the addictive behaviour
forward. The qualities that make the behaviour defined as addictive are in part the conventionality of the
behaviour and one’s initial preferences, the excessiveness of involvement in the behaviour, and one’s place in
society. With repeated participation in the behaviour, the salience of alternative behaviours decreases.
Furthermore, it becomes more difficult to find the alternatives (variance).
This notion is consistent with behavioural economics-type models of addiction-related behaviour as being
a choice (a self-destructive operant behaviour). Both show the existence of multiple schedules of reinforcement
associated with different behaviours (addictive vs. non-addictive), and they both involve different reinforcement
values and delays in delivery of reinforcement.
Six-component perspective (extensional)
This perspective has six different components. Salience refers to the tendency for the addiction to dominate
one’s thoughts, feelings, and behaviour. Mood modification refers to the rush, escape, or satisfaction that the
addictive behaviour serves. Tolerance refers to the process in which more of the behaviour is required to
achieve a level of mood modification. Withdrawal symptoms are the unpleasant feeling states or physical
effects of not engaging in the addictive behaviour. Conflict refers to the discord between engaging in the
addictive behaviour and relations with others, oneself, or engagement in other activities. Lastly, relapse refers
to the tendency to return to out-of-control addictive behaviour after periods of trying to stop or control it.
Five-component perspective (extensional)
This perspective considers appetitive effects, satiation, preoccupation, loss of control, and negative
consequences as components. Tolerance and withdrawal symptoms are not included because this perspective
regards those components as preoccupation. As tolerance increases, one likely spends more time locating and
engaging in an addiction. If withdrawal symptoms exist, and worsen, one is likely to be spending more and
