Anxiety disorders in children

Introduction

It is common for mental health problems to first occur in childhood. Global research has shown that a third of individuals experience their first mental health disorder before the age of 14 years, with anxiety disorders accounting for the majority of mental health conditions in this age group​[1,2]​. The median age of onset of mental health disorders as a whole is 11 years​[3]​. It has also been shown that approximately 7% of children worldwide have an anxiety disorder at any given time and around a quarter of people will have an anxiety disorder during their childhood years​[4,5]​.

Diagnosis of anxiety disorders in childhood has increased over the past two decades and further increases were observed during the COVID-19 pandemic​[6–9]​. A complex interplay of psychosocial and environmental factors influence the development of anxiety disorders; genetics is also a strong contributing factor, with children of parents who have an anxiety disorder significantly more likely to develop anxiety​[3,5]​.

Anxiety disorders can have significant effects on social functioning and educational attainment, with the potential for lifelong consequences. Having an anxiety disorder as a child increases the risk of having anxiety or depression as an adult. Additionally, experiencing anxiety in childhood also increases the risk of later suicide attempts, psychiatric admissions and abuse of alcohol or substances​[10]​.

An understanding of these conditions and how they are treated is essential for any healthcare professional working with children and their families, regardless of specialty.

Overview of anxiety disorders

The World Health Organization’s International Classification of Diseases system (ICD-11) was updated in 2023 and now more closely mirrors the Diagnostic and Statistical Manual (DSM-5)​[11,12]​. The previous version of ICD (ICD-10) categorised conditions, such as obsessive compulsive disorder and post-traumatic stress disorder, under the overarching heading of ‘anxiety disorders’. Now these conditions have their own separate categories in both classification systems and, as such, are not included in this article. 

Figure 1 shows the median age of onset by anxiety disorder.

Typically, anxiety disorders present with emotional and physical symptoms. The context in which symptoms occur, the age at onset and their triggers help to distinguish between them.

Selective mutism

Selective mutism generally begins in early childhood, typically from around the age of two years and at around an important milestone, such as starting nursery or preschool. However, it can occur at any time — including in adulthood — and occasionally, symptoms originating in childhood continue into adulthood. In some cases, extreme anxiety makes speaking impossible. An inability to speak is most often experienced in social situations, such as school, or in unfamiliar environments, while speaking in other settings can be unaffected.

Separation anxiety disorder

Separation anxiety disorder is the development of extreme anxiety about being separated from a major attachment figure (usually parents or other caregivers)​[11]​. It is developmentally normal for young children to experience some anxiety about being separated from their attachment figures, typically beginning at around the age of 6–12 months and continuing until around 3 years of age. However, assessment is warranted if the anxiety is extreme or develops in older children. Children with extreme separation anxiety often present with physical symptoms such as nausea, vomiting and headaches. They may sleep poorly, have nightmares about being separated, insist on sleeping with a parent and/or experience thoughts of the attachment figure coming to harm. The distress may present as tantrums, social withdrawal or school refusal. Although symptoms can persist, they often resolve as the child approaches adolescence.

Specific phobias

Phobias are one of the most common anxiety disorders overall, with most cases in children occurring around the ages of 7–10 years[11]. A specific phobia is defined as an irrational or extreme fear of an object or a situation, generally grouped into the following categories​[11]​:

• Animals (e.g. spiders, dogs);
• Natural phenomena (e.g. fire, storms);
• Situations (e.g. flying, heights);
• Medical (e.g. blood, needles). 

Again, excluding what is considered developmentally normal is important. For example, it is normal for young children to have some fear of the dark or of dogs and a normal response in these situations would be proportional, brief and respond to reassurance; however, if reactions are excessive, persistent and cause significant distress, leading to changes in behaviour that affects functioning, this departs from the norm and indicates a phobic disorder. Particularly in very young children, the fear response may present as a tantrum or cause a child to freeze. The intensity level of the response, coupled with the frequency and duration, are used to inform the diagnosis​[11]​. Typically, the main coping strategy is avoidance, which is seen in all ages​[11]​. A younger age at first onset is associated with an increased likelihood of having more than one phobia and, if symptoms persist throughout childhood and into adulthood, the phobia rarely spontaneously remits​[11]​.

Social anxiety disorder

Social anxiety disorder is an excessive fear or anxiety occurring in social settings with peers (e.g. holding conversations), or while being observed, such as answering questions in the classroom or eating in the school canteen. The person is overly concerned that they would embarrass themselves or be judged adversely by others and there may be intense physical symptoms, such as blushing and trembling​[11]​. Developmentally normal concerns about meeting new people or entering unfamiliar situations should be excluded. The dominant management strategy is avoidance, which may present subtly in young children (e.g. avoiding eye contact); however, as the child gets older and as social demands increase, the coping strategies may become more obvious, such as school refusal or withdrawing from activities that involve social interaction​[11]​.

Generalised anxiety disorder

While the typical age of onset is in the early- to mid-30s[11], generalised anxiety disorder (GAD) is one of the more common anxiety disorders of late adolescence​[2]​. It is less common in younger children, which might be because their cognitive ability is not sufficiently developed to be able to worry​[13]​. GAD is characterised by uncontrollable, excessive and persistent worries about everyday events, such as school, family, friendships and the future. Younger children tend to worry more about safety, their health and the health of others, whereas older adolescents worry more about their performance and meeting the expectations of others​[11]​. Worries are accompanied by many physical symptoms affecting several body systems: headaches, abdominal pain, gastric upset and poor sleep​[11]​. Additionally, children with GAD frequently seek reassurance, experience distress if faced with uncertainty, and can be particularly sensitive to perceived criticism​[14]​. 

Agoraphobia

Agoraphobia is the fear of situations where escape may be difficult or where help may be unavailable. In the absence of a pre-existing diagnosis of panic disorder, age of onset is generally around the mid-20s, but it can occur in late adolescence​[11]​. Onset earlier in childhood is rare. While the presentation does not differ significantly across the age range, the triggers can vary: for example, adolescents may be more likely than adults to fear being outside the home or becoming lost​[11]​.

Panic disorder

Panic disorder is characterised by the repeated unexpected occurrence of panic attacks (discrete episodes of intense fear accompanied by symptoms such as sweating, palpitations, shortness of breath or fear of imminent death) and the persistent worry of their re-occurrence. Most adolescents who experience an initial panic attack do not go on to develop the disorder​[10]​. The cognitive capacity for catastrophising about the significance of symptoms develops with age, meaning that panic disorder is rare in younger children. However, prevalence increases across adolescence, peaking in the early 20s.

Diagnosis

In the UK, the assessment and management of anxiety disorders in children is carried out by specialists within child and adolescent mental health services. An important consideration during the assessment process is determining whether symptoms deviate from developmentally normal fears and worries. The triggers for anxiety are generally normal experiences, such as putting a hand up in class, eating out, going to a party or sleepover, or being asked a question by a teacher. If reactions to such events are severe, disproportionate and persistent, or lead to a change in behaviour, such as school refusal, being unable to sleep alone or social withdrawal, then assessment is warranted.

While it is important to assess the child, ideally on their own if possible, taking a detailed history from the parent or caregiver is equally important, as this will help provide a more complete picture. When a person describes their symptoms, they are likely to use words other than ‘anxious’ or ‘anxiety’ (see Figure 2). 

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Comorbidity

Rates of comorbidity with other mental health conditions in young people with anxiety disorders is high, particularly the co-occurrence with another anxiety disorder​[15]​. There are many overlapping symptoms; therefore, an assessment should consider the possibility of a co-existing mental health condition and for an accurate anxiety diagnosis it is essential that other mental health conditions, speech and language problems, neurodevelopmental conditions, the use of drugs and alcohol, and other physical health conditions are all excluded as a cause of the presentation.

Diagnostic tools

Young people can find it difficult to verbalise their experiences, or they may feel embarrassed and be reluctant to share them with others. However, through careful and detailed evaluations, using a combination of self-report questionnaires and specialist clinician interviews, it is possible to accurately diagnose the individual anxiety disorders. 

The risk of suicidal thoughts and ideas is increased in anxiety disorders and a comprehensive assessment of risk should form part of each mental health assessment​[15]​.

It is a requirement for a diagnosis that symptoms must have been present for a sufficient period and be causing significant distress and impairment in functioning (see Table 1)​[11]​. 

There are many anxiety screening questionnaires available (see Table 2​[16–19]​). Some also include screening for other conditions and, not only are they a useful aid to an initial diagnosis, they can later be used again to provide a measure of response to treatment​[15]​. Questionnaires that measure impact on functioning can also be helpful.

Management of anxiety disorders

UK guidance is limited to the social anxiety disorder clinical guideline published by the National Institute for Health and Care Excellence (NICE)​[20]​. This guideline applies to all ages from school age to adults and recommends cognitive behavioural therapy (CBT) as the first-line treatment, advising against routinely offering pharmacological interventions for children and adolescents​[20]​.

CBT is well established and the most widely available psychological therapy for the treatment of anxiety disorders globally​[4]​. CBT is based on the premise that thoughts, feelings and behaviours are all connected. Challenging maladaptive thoughts through a gradual process of graded exposure, followed by reflection, facilitates new learning and allows the child to adapt and alter the way they perceive themselves and the world around them.

Other interventions, such as bibliotherapy and internet-based interventions, have a growing evidence base​[15]​. It remains unclear whether CBT is any more or less effective than other treatments, whether the method of delivery (e.g. group, individual, with parents or parent-only) affects outcomes, whether it is more or less effective for certain individuals (e.g. those with autism spectrum disorder), or what impact age and cognitive capacity may have on efficacy​[15,21–23]​. Although much of the published literature in this area has been carried out in children aged above seven years, there are also some positive findings in younger children​[15]​.

There is evidence that pharmacological interventions are effective and generally well tolerated in children and adolescents​[24–27]​. Guidance in other countries, such as the United States and Canada, often includes more detailed recommendations for their use​[4,28]​. Serotonin is an important neurotransmitter within brain networks that is important in anxiety and in the cognitive processing of these emotions; therefore, selective serotonin reuptake inhibitors (SSRIs) are considered first-line medicines. There is currently no UK-licensed SSRI for the treatment of anxiety disorders in patients aged under 18 years, nor has NICE provided specific guidance on which SSRI to select — the choice is largely determined by considerations such as pharmacokinetics and potential for drug interactions. SSRIs used for other conditions (e.g. depression) in this age group are usually selected, such as fluoxetine, sertraline, citalopram and escitalopram.

The relative effectiveness of CBT, medication or a combination of both is unclear. Limited evidence indicates that a combination may be more effective than either treatment alone​[25,29,30]​. In practice, particularly in older children or when symptoms are severe, a combination treatment approach is often employed. It may be necessary to use medication on its own, for example when a young person is unable or unwilling to engage in psychological treatment, or when delays in accessing psychological therapy would be detrimental.

Gradual dose titration is recommended, generally beginning with half a usual starting dose for at least the first week (e.g. 12–25mg/day sertraline or 5–10mg/day fluoxetine) before titrating to dose ranges usually used in adults (e.g. 50–200mg/day sertraline or 20–60mg/day fluoxetine). While there is no specific minimum age limit, the use of SSRIs is more commonly seen in teenagers than in younger children and use in very young children is rare. Children with a learning disability require a more cautious approach to the use of medication as they are at greater risk of side effects, so initial doses are often even lower. Symptoms improve slowly and may require 12 weeks or longer for maximal effects to be seen​[4]​.

SSRIs are generally well tolerated by children and adolescents with potential side effects similar to those seen in adults; however, behavioural activation and agitation occur with a higher frequency (see Box 1)​[4,27]​. This is one of the important counselling points (see Box 2).

When response is poor, switching to a different SSRI should be considered while also undertaking a holistic review. Issues such as treatment adherence and the use of non-pharmacological interventions should be considered. 

Widely used in adults as a treatment for anxiety, there is some (limited) evidence for the use of serotonin and noradrenaline reuptake inhibitors (SNRIs) in children​[27,31]​. The SNRI duloxetine is licensed in the United States for GAD in patients aged 7–17 years and is included in treatment guidance in the United States and Canada​[4,28]​. However, owing to a greater side effect burden and a relative lack of data, SNRIs are considered a third-line treatment in the UK and are infrequently used, generally only in older adolescents​[32]​. The use of other medicines, such as benzodiazepines, pregabalin and propranolol, have known safety concerns, are not supported by evidence in this age group and are therefore not recommended​[4,15,32]​. 

An effective medication should be continued for at least 12 months following remission of symptoms​[3,32]​.

Support needs of different age groups

It is important to involve parents and carers in anxiety management strategies, particularly with younger children. Children may benefit from social skills training and being taught coping skills. As parental anxiety can contribute to a child’s anxiety, it is also important to address this and any other needs of the parent or caregiver. Psycho-education is helpful for both the child and parent/caregiver, and providing guidance to parents/caregivers about how they can help their child’s anxiety, including positive parenting styles, is important​[28]​.