What about the development of anxiety and depression in young people? - Chapter 2

What is this chapter about?

Young adults (adolescents: 12 to 17 years) have more anxiety and/or depression problems compared to children. In 50% of adults with anxiety disorders, symptoms begin before the age of 12 – and for 75% of them symptoms are visible before their 21st birthday! Although there has been a lot of research conducted on individual risk factors for mental disorders, there has been little research conducted on development of mental disorders. Therefore, this chapter looks at the biological, cognitive and social changes during adolescence that may be related to the onset of such problems. In other words, the question is: why do so many of the persistent, long-term anxiety and mood disorders start so early in development?

Which environmental factors play a role in anxiety and depression?

Twin studies have shown that environmental factors play a major role in the rise (or rather the absence) of anxious and depressive feelings. Unfortunately, such studies cannot identify exactly what environmental factors are responsible for this. Some of the social factors that are often involved are:

• A single profound, stressful event (such as a divorce).
• Daily stressors within domestic circles (such as a parent-child relationship in which the overprotective, strict mother raises an anxious child).
• Negative interpersonal experiences outdoors (e.g. being bullied at school or at their sports club).

Such factors have a predictive value, but this does not mean that they are always a cause. In addition, anxiety and depression are both associated with a lack of social support that normally acts as a buffer against negative experiences. One drawback of these studies is that these results are only based on children and young adults in the Western world.

More complex twin studies (which unfortunately are also still only focused on Western society) suggest that new individual and environmental factors play a greater role in adolescents (for example, the transition to high school). Adolescents show a greater stress response to performance-oriented stressors during this developmental period compared to younger children. Also, adolescents are spending more and more time with their peers than with their families, which may lead to increasing parent-child conflicts. In general, young adults experience more stressful events, more daily hinderances and new stressors (such as ambiguous social situations).

Which genetic factors play a role during adolescence?

It is not (yet) possible to identify specific genes that affect anxiety symptoms or depression symptoms. Although in adults with anxiety and mood problems it has been implied that they often have a short form of the serotonin transporter gene, this is less implied in children and young adults. But, how could genes have more influence during a certain developmental phase (since DNA is stable over time)?! The answer according to  Gesell's (1932) “Maturationist” theory is that genes that contribute to anxiety and depression can be "turned on"(maturing) by certain experiences throughout development! There are multiple genetic factors and many environmental factors that can (influence) each other to varying degrees: thus there is an interaction between the environment and DNA.

Which changes take place in the emotional and social brain?

The "emotional brain" refers mainly to four brain circuits: the amygdala, the striatum (caudate, putamen and nucleus  accumbens – have to do with detecting emotions, especially fear), areas that become active when anticipating and experiencing rewards, and areas of the prefrontal cortex (PFC) that regulate emotional responses through complex processes (such as decision-making). The "social brain" refers to a circuit that partially overlaps with these areas, including the amygdala, because there is also an emotional component of social activities. Other – typically "social" areas – are associated with social cognition, such as understanding other people's perspective or recognizing faces. During adolescence, compared to younger children and adults, there is increased subcortical activity, both in the amygdala and the striatum. In particular, the amygdala is more active in adolescents with anxiety and mood problems. Although the subcortical structures mature early, the PFC is not yet fully matured (thus there is less white matter compared to adults). The PFC could normally regulate this strong/increased reaction of the amygdala. Both the function (such as the strong activation of the amygdala and  striatum) and the structure of brain regions (such as the immature PFC areas) are therefore partly responsible for the way emotional and social information is processed in adolescence.

Is there a bias in information processing?

Anxiety and depression are often associated with biases in cognition. Children and young adults with anxiety symptoms have an automatic bias and thus more attention for threatening information (attention-orientation bias), which also leads them to have more difficulty turning away from such information (attention-checking  bias). Although it is a little more complicated for depressed children and young people, in both types of disorders individuals tend to quickly label information as "threatening". Mood symptoms are also associated with a memory bias for negative information. Other cognitive biases include a negative/dysfunctional attribution style (success is due to external factors; failure is due to the person's own (internal) factors), dysfunctional attitudes, and negative interpersonal  cognitions. As children age (and enter adolescence), the interaction between life events and a negative attribution style plays an increasingly important role in the development of depressive symptoms. Other cognitive biases also become more stable and cohesive as children enter adolescence.

What can be concluded?

There are multiple age-related  changes during adolescence that occur when anxious and/or depressive symptoms first emerge. Recent studies use  cognitive bias modification (CBM) techniques that try to correct cognitive biases: this is how patients learn to shift their attention away from negative things and to assign positive interpretations to (ambiguous) information.

Young adults (adolescents: 12 to 17 years) have more anxiety and/or depression problems compared to children. In 50% of adults with anxiety disorders, symptoms begin before the age of 12 – and for 75% of them symptoms are visible before their 21st birthday! Although there has been a lot of research conducted on individual risk factors for mental disorders, there has been little research conducted on development of mental disorders. Therefore, this chapter looks at the biological, cognitive and social changes during adolescence that may be related to the onset of such problems. In other words, the question is: why do so many of the persistent, long-term anxiety and mood disorders start so early in development?