Topic 2 Basic signs for recognizing internalizing and externalizing disorders in children and adolescents

As already stated in Unit 1, mental health difficulties in children and adolescents can be classified into two broad categories: internalizing and externalizing difficulties.

The most common internalizing mental disorders in children and adolescents are mood disorders (e.g., depression), anxiety disorders and stress-related disorders (Elia, 2021). Most common externalizing disorders are Attention-Deficit/Hyperactivity Disorder (ADHD), conduct disorder and oppositional defiant disorder.

Recognizing depression:

Most significant mood disorder in children and adolescents is depression. Depression was present within a one-year interval in around 13% of US adolescents (Monaco, 2021). In children, the prevalence was lower, around 2% (Abela and Hankin, 2009).

Source: a photo by K. Mitch Hodge on Unsplash
According to DSM-5 (APA, 2013), depression can be manifested by the following symptoms:
1. Depressed mood, most of the days and nearly every day.
6. Fatigue or loss of energy nearly every day.
2. Markedly diminished interest or pleasure in all, or almost all, activities most of the day nearly every day.
7. Feelings of worthlessness or excessive and inappropriate guilt.
3. Significant weight loss or weight gain (in children, this can be a failure to make the expected weight gain).
8. Diminished ability to think or concentrate or indecisiveness, nearly every day.
4. Cannot sleep or sleeps too much nearly every day.
9. Recurrent thoughts of death and suicidal ideation or attempting suicide.
5. Psychomotor agitation (e.g., pacing, hand-wringing or inability to sit still) or psychomotor retardation (slowing down mental and physical activities).
source: Black boxes with symptoms are editable for translation

One must report 5 out of 9 symptoms over a 2-week period to be diagnosed with major depression, but fewer symptoms can point to depression as well, if a person is impaired in their academic, social, and other functioning (Martin et al., 2017). Most important symptoms are: 1. depressed mood and 2. loss of interest or pleasure, and at least one of these symptoms must be present for a person to be diagnosed with depression. In children and adolescents, the depressed mood can manifest itself as irritability as well.

Besides the described symptoms, there are additional emotional and behavioural changes that can help us recognize depression in children and adolescents (Mayo Clinic, n.d.). Additional emotional changes can be low self-esteem, fixation on past failures, extreme sensitivity to rejection or failure and ongoing sense that life and the future are grim and bleak.

Additional behavioural changes can be the (ab)use of alcohol or drugs, frequent complaints of unexplained body aches and headaches, social isolation, poor academic performance or frequent absence from school, less attention to personal hygiene or appearance

As depressed mood is the one of the most important features of depression, it is important to differentiate it from sadness. Sadness can occur because, for example, a child’s family member gets very sick from a communicable disease. Sadness is usually caused by a specific trigger, and one can find some relief in crying, venting, or talking out frustrations (Fitzgerald, 2019).

Regular sadness usually fades with time. Depression is a long-term mental illness that requires professional treatment with psychotherapy and medication. In depression, a person feels sad or hopeless about everything. It is important to note that a person can be sad because of something and depressed in general at the same time, one does not exclude the other.

Similar is the difference between depression and grief (APA, 2013). A child can go through a period of grief if, for example, their family member dies from a health threatening emergency. In grief, the dominant feelings are emptiness and loss, whereas in depression it is persistent depressed mood and the inability to feel happiness or pleasure.

Grief is likely to decrease in intensity over days or weeks and occurs in waves, which are called “pangs of grief” (APA, 2013). These pangs tend to be connected to the thoughts or reminders of the deceased. Although the person who griefs is in pain, grief can be accompanied with positive emotions and humour. Conversely, depression is characterized by pervasive misery and unhappiness.

Persons in grief often think about and remember the deceased, but in depression the thoughts are self-critical and pessimistic, and the person feels worthless. If negative thoughts about oneself are present in grief, this is only because the person thinks they failed the deceased in some way (e.g., they didn’t visit enough or tell the person how much they loved them).

Anxiety disorders are present in around 3% of 6-year-olds, 5% of teenage boys and 10% of teenage girls (Elia, 2021). There are different anxiety disorders. Generalized anxiety disorder, panic disorder, separation anxiety disorder, social anxiety disorder and specific phobias are among most common anxiety disorders in children and adolescents (Creswell et al., 2020).


Although there are too many individual anxiety disorders to delve into details, there are general outward signs that we can use to recognize anxiety in children and adolescents (National Health Service, n.d.). A child or an adolescent might have an anxiety disorder if it is:

  • finding it hard to concentrate
  • not sleeping, or waking in the night with bad dreams
  • not eating properly
  • quickly getting angry or irritable and being out of control during outbursts. This might be similar to oppositional behaviour, but it can be the consequence of anxiety and triggering the fight-or-flight mechanism (Boorady, n.d.).
  • constantly worrying or having negative thoughts
  • feeling tense and fidgety, or using the toilet often (“Not all that moves is ADHD”).
  • always crying  (continued on the next slide)
  • being clingy and experiencing strong anxiety when separated from the primary attachment figure (e.g., the mother), being too worried about losing the primary attachment figure

  • complaining of stomach aches or feeling unwell


  • experiencing panic attacks

  • being extremely shy and withdrawing from new situations or from people

  • feeling an inappropriate amount of fear when exposed to observation and possible assessment in different social situations; being afraid of: public speaking, oral exams, stating your opinion in front of a larger group of people, talking with peers, eating or playing in front of other children


Source for the picture in the middle:


Some amount of anxiety is normal for every child, but it becomes an issue when anxiety and fear are not proportional to the level of threat, and they start to interfere with children’s everyday lives. Anxious children can become withdrawn and try in all ways to avoid things or situations that cause the anxiety.

Children may have anxieties that will go away on their own or with the help of parents, however, anxiety disorders have a serious negative impact on the children’s and adolescent’s quality of life and on their functioning and should be treated by professionals (National Health Service, n.d.).

It is assumed that anxiety disorders stem from a combination of factors: some children are born more anxious and less able to cope with stress, they can pick up the behaviour from being around anxious people and they can become more prone to developing the disorder by experiencing stressful events, some of which may be related to mental health emergencies as well (e.g., frequently moving house or school, parents arguing, death of a close relative, being seriously ill or injured, bullying or exams in school, abuse or neglect).

There are different trauma and stress related disorders in children and adolescents (Children’s Hospital in Philadelphia, n.d.; APA, 2013). Post-traumatic stress disorder, acute stress disorder and adjustment disorder are the most common ones.



Post-traumatic stress disorder (PTSD) is characterized by persistent, intrusive, and frightening thoughts and memories, flashbacks or dreams featuring traumatic event or events. These traumatic events should be extreme, e.g., actual or threatened death, serious injury or sexual violence happening to the person or to a close family member (in which case death or injury must be violent or accidental) or witnessing a traumatic event as it occurred to others. Other PTSD symptoms include:

– persistent avoidance of stimuli associated with traumatic events (memories, thoughts, people, places, conversations)

– alterations in cognitions and mood associated with the traumatic event (blaming oneself, persistently being in a negative emotional state, being less interested to participate in significant activities, having less ability to experience positive emotions)

-alterations in arousal and reactivity associated with the traumatic events, such as angry outbursts, reckless or self-destructive behaviour, hypervigilance, problems with concentration and sleep disturbance.

Acute stress disorder has symptoms that are similar to the PTSD, but occurs within the first month after exposure to trauma. With prompt treatment and social support, its progression to PTSD can be prevented.

Adjustment disorder assumes developing unhealthy emotional and behavioural reactions in response to an identifiable stressor, which occurs within 3 months of its onset. Affected children and adolescents may display depressed mood or nervousness or they may behave so that they violate the rights of others.

Trauma and stress-related disorders may be especially relevant in the context of health emergencies. A review of studies (Loades et al., 2021) found that self-isolation in the context of different infections in children carries a risk for developing acute stress disorder, adjustment disorder or even post-traumatic stress disorder.

Externalizing disorders, also known as behavioural disorders or externalizing behaviour disorders, include attention deficit hyperactivity disorder (ADHD), conduct disorder (CD), and oppositional defiant disorder (ODD) (Samek and Hicks, 2014). Because their symptoms are more visible, they are usually noticed more often by teachers than internalizing disorders such as depression and anxiety (Undheim et al., 2016).



ADHD has three main subtypes, the inattentive type, the hyperactive-impulsive type, and the combined type, which is a combination of the former two types (APA, 2013; Leonard, 2021).

A child with inattentive type ADHD can:

  • have difficulties paying attention
  • become easily distracted
  • have difficulty focusing on tasks, for example longer tasks such as reading
  • start tasks but forget to finish them
  • appear not to listen to instructions or to forget them


A child with hyperactive-impulsive type ADHD can:

  • have difficulties remaining seated
  • fidget a lot by tapping the hands, feet, or moving around in the seat
  • run around or climb things when this is not appropriate
  • frequently interrupt conversations or games
  • have difficulty waiting for their turn
  • have trouble talking or playing quietly


Oppositional defiant disorder usually first appears during preschool years and rarely after early adolescence. Its prevalence is around 3.3% (APA, 2013). Its characteristics are:

  • angry and irritable mood, in the sense that a child often loses temper, is touchy or easily annoyed or is often angry and resentful
  • defiant behaviour, in the sense that the child often argues with adults, often actively defies or refuses to comply with requests from adults or with rules, often deliberately annoys others or often blames others for his or her mistakes or misbehaviour
  • vindictiveness, in a sense that a child has been spiteful or vindictive at least two times over 6 months


Some of these behaviours are normal for children, but if they occur more often than it is suitable according to the cultural norms and the child’s developmental level, this may point to a disorder.

Some children and adolescents with oppositional defiant disorder symptoms eventually develop conduct disorder. Median one year prevalence of conduct disorder is 4% (APA, 2013).

Children and adolescents with conduct disorder violate basic social rules and the rights of others. These behaviours are much more severe than those in oppositional defiant disorder.

Symptoms of conduct disorder can include:

  • aggression, which can result in physical fights, bullying behaviour, threatening and intimidating others, stealing from a victim, using a weapon (e.g., a broken bottle, a knife) or being physically cruel to people and animals and forcing someone into sexual activity
  • destruction of property, like setting fires or damaging possessions
  • deceitfulness or theft, for example stealing items of nontrivial value, lying to obtain goods and services
  • significant rule-breaking, such as not going to school, running away from home or staying out despite parental prohibitions


Children and adolescents with conduct disorder can have difficulties feeling empathy, or suffer from another condition, such as anxiety or ADHD (APA, 2013). They may falsely interpret intentions of other people as mean (Ogundele, 2018).

Like other disorders, conduct disorder causes significant impairment in social, academic or occupational functioning. Specifically, these children and adolescents are sometimes suspended or expelled from school, start early with substance use and engage in reckless acts, and can come into contact with the legal system.

It is theorized that the oppositional defiant and conduct disorders are caused by a combination of a difficult child temperament and ineffective parenting practices, which leads children to interact with parents aggressively and defiantly. This aggressive strategy leads to sibling conflict, rejection by prosocial peers and academic setbacks in early childhood. Children then associate with other deviant peers, which reinforces their antisocial behaviour and attitudes during adolescence (Samek and Hicks, 2014).

At the end, it must be noted that, in internalizing and internalizing disorders, comorbidity (i.e., co-occurrence of the disorders) is more of a rule than an exception. For example, having an anxiety disorder can lead to depression. Also, having ADHD can lead to depression, as well as having oppositional defiant disorder or conduct disorder (Martin et al., 2017).