Anxiety disorders are the most frequent psychiatric disorders in children and adolescents, affecting between 15 – 20% of youths.¹ Anxiety disorders in youths are associated with increased morbidity and mortality as well as an increased risk of suicide attempts.^2,3 Longitudinal data suggest that young people with anxiety disorders are three times more likely to have anxiety or depression in adult life.⁴ They are also at increased risk of substance misuse.  

   Child and adolescent anxiety disorders are linked with poorer long-term general health and functioning, as well as interpersonal, financial and educational difficulties.⁵ Early and effective treatment may help prevent continuity of psychopathology into adulthood.

There is considerable heterogeneity in the onset of specific anxiety disorders, with generalised anxiety disorder (GAD), phobic anxiety, panic disorder and obsessive compulsive disorder (OCD) mostly emerging in adolescence.⁶

Diagnostic classification

Generalised anxiety disorder

GAD (ICD-10, F41.1) is characterised by chronic, excessive worry in a number of areas such as schoolwork, social interactions, family, health/safety and world events. Children with GAD have trouble controlling their worries, they are often perfectionistic, show high reassurance-seeking and may struggle with more internal distress than is evident to others. Symptoms are generally present most days for at least several weeks, and usually for several months. There is associated impairment in social functioning. Symptoms include worry or apprehension, muscular tension, fatigue, poor concentration, irritability and sleep disturbance.

Social phobia

Social phobia (F 40.1) is characterised by feeling scared or uncomfortable in one or more social settings or performance situations. The discomfort is associated with social scrutiny and the fear of doing something embarrassing. These individuals may have difficulty eating in public, answering questions in class, reading aloud, initiating conversations, talking with unfamiliar people and attending parties or social events. A fear of vomiting in public may also be present. Social phobias are usually associated with low self-esteem and fear of criticism. Avoidance is marked and may result in social isolation. Unlike most phobias, social phobias are equally common in men and women.

Agoraphobia

Agoraphobia (F 40.0) refers to an interrelated and often overlapping cluster of phobias embracing fears of leaving home to somewhere where it is difficult to escape to a safe place. The anxiety must occur mainly in at least two of the following situations: crowds, public places, travelling away from home or travelling alone.

Panic disorder

The essential features of panic disorder (F 41.0) include recurrent attacks of severe anxiety or panic that are unpredictable and not restricted to any particular set of circumstances. Symptoms vary from person to person but include palpitations, chest pain, choking sensation, dizziness, feelings of unreality (depersonalisation/derealisation). Psychological fears of losing control, dying or going mad may be present. A crescendo of autonomic symptoms often results in an exit from the situation and subsequent avoidance, which re-enforces the underlying anxiety.

Neurobiology of paediatric anxiety

There have been significant advances in the understanding of the neurobiology of childhood anxiety disorders in recent times, with dysfunction in the pre-frontal amygdala-based circuits being widely implicated.⁷ The amygdala, responsible for the initiation of the fear response, is often ‘over-activated’ in fMRI. Intrinsic functional connectivity networks between the amygdala and the pre-frontal cortex, anterior cingulate cortex, insula and cerebellum have also been implicated. The ventrolateral pre-fontal cortex (VLPFC), which regulates amygdala activity and plays a role in the extinction of the fear response, is also hyperactivated in youths with anxiety.⁸

Differential diagnosis

Differentials that can mimic the symptoms of anxiety include ADHD (restlessness, inattention), ASD (social awkwardness, social skills and communication deficits), learning difficulties (persistent worries about school performance), depression (difficulties with sleep, inattention, somatic complaints) and bipolar disorder (irritability, insomnia, restlessness). 

Anxiety may also be mimicked by a range of physical health conditions including endocrine abnormalities (hyperthyroidism, hypoglycaemia, pheochromocytoma), neurological disorders (migraine, epilepsy, brain tumours), cardiovascular conditions and (arrhythmias) medications including steroids, anti-asthmatics, sympathomimetics and SSRIs. These can cause anxiety symptoms in addition to caffeine, energy drinks and some over-the-counter/internet-bought medicines including antihistamines, cold medicines and diet pills.

Screening and assessment

Practice parameters from the American Academy of Child and Adolescent Psychiatry (AACAP)⁹ recommend screening for anxiety symptoms, noting the severity and functional impairment and assessing for comorbidity. Screening for general medical conditions that may mimic anxiety is also recommended. Evaluation should differentiate from developmentally appropriate worries and fears and should consider stressors or traumas that may be contributing to the anxiety. Anxiety-related symptoms such as crying, irritability or anger outbursts, which are sometimes misinterpreted by adults as oppositionality or disobedience, may represent the young person’s distress and efforts to avoid the anxiety-provoking stimulus.

Treatment

The AACAP guidelines⁹ suggest multi-modal treatment including psychoeducation, psychotherapy – eg. cognitive behavioural therapy (CBT) – and pharmacotherapy. Family support/therapy is often useful depending on parental anxiety, parenting style and attachment patterns, family problem-solving and familial relationships. Pharmacotherapy is recommended for moderate to severe symptoms.

The Childhood Anxiety Multimodal Study (CAMS)¹⁰ involved 488 youths aged between seven and 17 years. This study showed that monotherapy with sertraline (55% response) is as effective as CBT for anxiety (60% response) compared with placebo (24% response), and that a combination of sertraline and CBT is most likely to be successful (81% response). Some 80% of acute responders maintained their positive response at follow-up (24 and 36 weeks). Six-year naturalistic follow up of this group suggested that results were maintained with remission rates of 52% (sertraline only), 49% (combination therapy), and 46% (CBT only). Nearly half of responders had relapsed during the follow-up period suggesting that extended treatment is needed to maintain treatment gains.¹⁰

Pharmacotherapy

SSRIs are the medications of choice for the treatment of anxiety disorders in children and adolescents. A summary of randomised controlled trials of SSRIs in treating anxiety disorders in youths indicates that the benefits outweigh the risks for most SSRIs (sertraline, fluoxetine, fluvoxamine and paroxetine). There is insufficient data, however, for the remaining SSRIs and the SNRI desvenlafaxine.¹¹

For Venlafaxine XR, one publication showed positive results but lower effect sizes than with SSRIs and significantly higher adverse effects compared to placebo.¹² The NNT for most SSRIs and SNRIs over placebo is estimated to be between three and six.¹³

Sertraline and fluoxetine have been approved by the FDA for the treatment of paediatric OCD and are first-line treatments for anxiety. SNRIs could be considered a third-line treatment for anxiety disorders when two trials with different SSRIs prove ineffective.

Adverse effects of medications

Physical side-effects of SSRIs include headaches, gastric upset, insomnia and hypersomnia. Emotional or behavioural effects include hyperactivity, irritability, disinhibition and self-harm.¹⁴ The FDA issued a black box warning in 2004 for concerns related to worsening of depression, agitation and suicidal ideation linked to SSRIs. Studies report one excess case of suicidal ideation or self-harm per 100 treated individuals with anxiety compared to placebo, and two excess cases of suicidal ideation or self-harm per 100 treated individuals with depression compared to placebo.¹⁵ 

However, overall, SSRI treatment significantly decreases suicidal ideation and suicide attempts in young people and it is far more likely that SSRI use decreases suicide rates rather than increases them.¹⁶

The efficacy and safety of buspirone and mirtazapine in young people with anxiety disorders are not known, although open label studies suggest that they might be effective in relieving anxiety symptoms. Benzodiazepine use is not supported by clinical trials in youths and may lead to paradoxical disinhibition. Rarely, benzodiazepine use can be considered in practice to potentiate the therapeutic effect during initial titration of SSRIs or to mitigate adverse effects. It is also used for rapid tranquilisation.

As a general rule when prescribing in adolescents, start at the lowest available dose and monitor closely, usually within a week or two of starting treatment. Doses are to be increased cautiously and with careful monitoring. Overall therapeutic effect should appear within six to eight weeks of commencing treatment. Medications, if effective, should continue for at least one year of stable improvement. Tapering of medications, when indicated, should also be done slowly to minimise the risk of discontinuation symptoms.

Psychotherapy

CBT is a well-regarded and effective evidence-based treatment for child and adolescent anxiety disorders.¹⁷ CBT has several key components including psychoeducation, somatic skills training (relaxation, breathing exercise), cognitive restructuring by challenging anxiety-provoking thoughts and negative self-talk, problem solving, systematic exposure and desensitisation to the feared situation, and relapse prevention.¹⁸ A number of studies have also shown benefit of group CBT in youths with anxiety.¹⁹ CBT is not effective for all youths with anxiety disorders; a portion may continue to meet criteria for an anxiety disorder even after treatment.

Although often used, evidence for psychodynamic psychotherapy for youth anxiety is sparse and more studies are needed. Mindfulness has been increasingly used recently to promote health and wellbeing. Randomised controlled trials in anxious adults show significant improvement in anxiety symptoms.²⁰ Studies of mindfulness-based interventions are more limited in children and adolescents; however, this area warrants further investigation.

Management in primary care

Mild cases of anxiety can usually be treated in the community with psychoeducation and individual psychological intervention, eg. CBT, depending on locally available resources. Factors that influence referral to specialist adolescent mental health services include illness severity, comorbidity, risk management, positive family history or family dysfunction. Medications can be used for people presenting with a moderate to severe level of impairment in conjunction with individual therapy. 

References on request