The way in which adolescents respond to these changes, is partly shaped by earlier life experiences. The good news is that early life experiences do not necessarily dictate future outcomes, and adaptive neural plasticity -  the brain’s ability to grow and change in response to experiences – peak in adolescence marking it as a window of opportunity for change.^1,2

Biological changes

Biological transformations during adolescence signals the shedding of childhood bodies and transition to adult bodies, and the ability to reproduce. Puberty onset is associated with the release of specific hormones in the brain. Variations in hormone levels contribute to distinct outcomes in boys and girls.³

Cognitive changes

Cognitive development in adolescence involves significant brain changes. The brain undergoes three key processes: Prolific growth of new cells, pruning excess cells, and strengthening connections between cells through fatty tissue insulation.³

A recent study by Sydnor et al (2023) tracked changes in brain activity across ages, as well as the influence of adolescents’ socioeconomic environment on cognitive development. Results showed that the plasticity of brain systems involved in learning and emotional development peak at around 15-years and decline from there, suggesting a sensitive period during which their brains are primed for adapting and changing in response to their environment.²

The effects of the socioeconomic environment on brain function also peak in mid-adolescence and were strongest in areas such as the prefrontal cortex, indicating that the regions that showed greater plasticity in adolescence were also those most susceptible to environmental influence.²

Adaptive neural plasticity, play a crucial role in changing behaviour. As mentioned, this phase serves as a window of potential change, where mechanisms of resilience, recovery, and development can actively come into play, conclude Sydnor et al.²

Psychosocial changes

The social development process propels adolescents from childhood into the broader responsibilities of adulthood. Personal connections undergo significant changes, with peers and romantic relationships taking on greater importance that family in some instances.^1,3

Emotional changes

Emotional development is a biological process driven by physical and cognitive changes and heavily influenced by the environment. Factors like self-esteem, identity formation and stress all play a role in emotional development.³

During adolescence, changes in the brain promote deeper and more abstract thinking, a crucial aspect of emotional development. This cognitive shift shapes adolescents' perspectives on the world, influencing their interactions and the development of morals and values for adulthood.³

Possibilities and probabilities

In their book, The Origins of You, Belsky et al share that evidence shows that human development is a matter of possibilities and probabilities. The interplay between the above-mentioned changes and other influences, shapes adolescents’ road to adulthood.^1,4

 Genetics also play a huge role. Disorders that are most likely to have a genetic component include bipolar mood disorder, schizophrenia, and ADHD.⁵

 Environmental factors such as head injury, poor nutrition, and exposure to toxins (including lead and tobacco smoke) can increase the risk of developing a psychiatric disorder.⁵

 Social stressors include for example childhood sexual and physical abuse, obesity, socioeconomics (eg overcrowding, poverty, malnutrition), and the death of a family member or close friend.^3,5

Other notable factors that contribute to mental well-being in the South African context include, amongst others, high levels of racial inequality, gender inequality, disability, and gender-based violence at home.⁶

Prevalence of psychiatric disorders in childhood and adolescence

A 2022 global study examined the prevalence of psychiatric disorders across 204 countries and various age groups. The study reported a significant rise in disability-adjusted life years due to psychiatric disorders, increasing from 80.8 million to 125.3 million between 1990 and 2019. Psychiatric disorders now rank among the top ten leading causes of disease.⁷

A meta-analysis spanning 11 countries from 2003 to 2020 found that the prevalence of psychiatric disorders in high-income countries is 12.7%. The leading psychiatric disorders identified in children are anxiety (5.2%), ADHD (3.7%), oppositional defiant (3.3%), substance use (2.3%), conduct (1.3%), and depressive (1.3%) disorders.⁸

According to the World Health Organization, an estimated 4.6% of 15- to 19-year-olds experience an anxiety disorder, while 1.1% of 10- to 14-years-olds and 2.8% of 15– to 19-year-olds experience depression. Suicide is the fourth leading cause of death among 15- to 29-year-olds.⁹

The South African Child Gauge 2021/2022 states data on child and adolescent psychiatric disorders in the country are limited. Some studies estimate that the prevalence of psychiatric disorders in South African adolescents is ~17%.⁶

There is also a high burden of substance abuse disorders in South Africa, where 20%-49% of those admitted to drug treatment centres in the first six months of 2020 were 10- to 19-year-olds.⁶

Treating psychiatric disorders in childhood and adolescents

In the next part of the article we will focus on the treatment of anxiety and depressive disorders. Around 40% of adolescents living with one psychiatric disorder also grapple with another.¹⁰

There is a four-fold risk of developing both anxiety and depression, and a three-fold risk of developing both depression and substance use disorders. To disability associated with adolescent anxiety, depression, and potential comorbidities, early intervention is crucial.¹⁰

The Diagnostic and Statistical Manual of Mental Disorders fifth edition (DSM-5) classifies anxiety disorders into various categories: Anxiety disorder due to other medical conditions is characterised by anxiety symptoms as a physiological consequence of another medical condition such as endocrine, cardiovascular, respiratory, metabolic, neurological, or seizure disorders.¹¹

Agoraphobia involves fear and anxiety in situations like public transportation or open spaces, leading to avoidance. Generalised anxiety disorder (GAD) manifests as persistent, excessive worry about various domains, accompanied by restlessness, fatigue, difficulty concentrating, irritability, muscle tension, and sleep disturbance.¹¹

Panic disorder is comorbid with other psychiatric disorders, and attacks may occur unexpectedly or in response to triggers, leading to agoraphobia. Selective mutism is marked by a consistent failure to speak in specific social situations. Separation anxiety disorder involves excessive fear of harm, loss, or separation from attachment figures, with symptoms persisting into adulthood.^11,12

Specific phobias are unwarranted fears of specific objects or situations leading to avoidance. Social anxiety disorder (SAD) is characterised by intense fear of negative evaluation in social situations, leading to avoidance.

Substance/medication-induced anxiety involves anxiety symptoms due to substance intoxication or withdrawal.^11,13,14

The DSM-5 distinguishes between the following forms of depression:¹⁵

• Major depressive disorder (MDD)
• Persistent depressive disorder, formerly known as dysthymia
• Disruptive mood dysregulation disorder
• Premenstrual dysphoric disorder
• Substance/medication-induced depressive disorder
• Depressive disorder due to another medical condition
• Unspecified depressive disorder.

Signs and symptoms of MDD include persistently low or depressed mood, anhedonia or decreased interest in pleasurable activities, feelings of guilt or worthlessness, lack of energy, poor concentration, appetite changes, psychomotor retardation or agitation, sleep disturbances, or suicidal thoughts.¹⁶

MDD is classified as mild (five symptoms), moderate (six to seven symptoms), and severe (eight to nine symptoms). Severe depression is associated with a high risk of suicide.¹⁶

Treatment recommendations

Anxiety disorders

Non-pharmacological first-line interventions include cognitive behavioural therapy (CBT) and acceptance and commitment therapy (ACT), a newer modality.¹⁷

Pharmacotherapies include selective serotonin reuptake inhibitors (SSRIs), notably fluoxetine and sertraline, which are recommended as first-line treatments for GAD.¹⁷

Depressive disorders

Non-pharmacological interventions include CBT and interpersonal therapy. Both are well-established modalities for the treatment of MDD. ACT promotes long-term behaviour changes and is just as effective as CBT. The integration of cognitive restructuring, caregiver involvement, and behavioural activation enhances CBT outcomes.¹⁷

First-line pharmacotherapy for MDD include SSRIs (fluoxetine, escitalopram, sertraline). Fluoxetine is well-tolerated, with rare adverse reactions. The serotonin–norepinephrine reuptake inhibitor (SNRI) duloxetine can be used as an alternative, although side effects are more common than with the use of a SSRI. Tricyclic antidepressants pose cardiac risks, requiring careful monitoring.¹⁷

Combining of pharmacotherapy and psychotherapy

Guidelines advocate a stepped-care approach. Mild cases involve watchful waiting, followed by non-pharmacologic interventions. Persistent symptoms may require augmentation with pharmacotherapy.¹⁷

Adjunctive therapies

Apart from psycho- and pharmacotherapies, various adjunctive interventions hold promise to alleviate the symptoms of anxiety and depression in children and adolescents.¹⁷

These lifestyle interventions are crucial, considering the persistence of anxiety and depression into adulthood. Modifying dietary habits is a practical intervention and studies suggest that a diet rich in fruits, vegetables, grains, and dairy products correlates with fewer primary care visits for symptoms associated with anxiety and depression.¹⁷

Avoiding caffeine and cannabis products is linked to improved adolescent mental health. Dietary supplements like omega-3 fatty acids, probiotics, vitamin D, and folate are considered adjunctive therapies.¹⁷

Omega-3 supplementation corrects neurotransmitter dysfunction, while probiotics contribute to a healthier gut microbiome, positively impacting mental health.¹⁷

Deficiencies in vitamin D and folate are associated with depression, and supplementation has shown improvement, particularly in adolescents with specific gene mutations.¹⁷

Exercise interventions have also been proven to be highly effective in reducing anxiety and depression symptoms. Studies indicate higher adherence to exercise treatments compared to psychological and drug therapies.¹⁷

Yoga and aerobic exercise stand out, with yoga significantly reducing anxiety symptoms, and aerobic exercise consistently reducing depressive symptoms.¹⁷

Meeting or exceeding the recommended 60 minutes of moderate to vigorous exercise per day demonstrates the greatest reduction in depressive symptoms. Sports participation further aids in symptom reduction.¹⁷

Increased screen time correlates with heightened anxiety and depression severity. Limiting screen time to less than two hours per day, coupled with achieving nine to eleven hours of sleep, significantly reduces doctor visits.¹⁷

Decreased exposure to natural environments is linked to rising anxiety and depression rates. Nature-based interventions, including outdoor therapies and wilderness expeditions, offer substantial mental health benefits.¹⁷

Access to natural outdoor spaces improves mental health, particularly for lower socioeconomic status and high population density areas. Structured wilderness therapy programmes are recommended for some patients.¹⁷

While lacking specific studies for anxiety and depression in child and adolescent patients, osteopathic manipulative treatments show promise in improving heart rate variability.¹⁷

Techniques like cervical soft tissue kneading, sacral decompression, and respiratory diaphragm doming may downregulate the sympathetic nervous system, potentially reducing symptoms.¹⁷

Conclusion

Adolescence, marked by biological, cognitive, psychosocial, and emotional changes, signifies a critical period of adaptive neural plasticity, offering a window for positive development.

Factors such as genetics, environment, and societal stressors contribute to mental well-being. Treating psychiatric disorders in childhood and adolescence is paramount, with early intervention crucial to mitigating potential comorbidities.

Non-pharmacological interventions like CBT is recommended as first-line therapies for children and adolescents. Recommended pharmacotherapies  include SSRIs and SNRIs. A combined approach with psychotherapy is beneficial.

Adjunctive interventions include lifestyle changes, dietary modifications, exercise, screen time reduction, nature-based therapies, and potentially osteopathic manipulative treatments.

These diverse approaches underscore the importance of a comprehensive strategy in addressing psychiatric disorders in children and adolescents, promoting mental health and well-being.

REFERENCES

1. National Academies of Sciences, Engineering, and Medicine. Health and Medicine Division, Division of Behavioral and Social Sciences and Education; Board on Children, Youth, and Families; Committee on the Neurobiological and Socio-behavioral Science of Adolescent Development and Its Applications. Backes EP, Bonnie RJ, editors. The Promise of Adolescence: Realizing Opportunity for All Youth. Washington (DC): National Academies Press (US); 2019 May 16. 2, Adolescent Development. Available from: https://www.ncbi.nlm.nih.gov/books/NBK545476/
2. Sydnor VJ, Larsen B, Seidlitz J, et al.Intrinsic activity development unfolds along a sensorimotor–association cortical axis in youth. Nat Neurosci, 2023.
3. US Department of Health and Human Services. Office of Population Affairs, Adolescent Development Explained. Washington, DC: US Government Printing Office. 2018. [Internet]. Available from: https://opa.hhs.gov/sites/default/files/2021-03/adolescent-development-explained-download.pdf
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7. Mental Disorders Collaborators. Global, Regional, and National Burden of 12 Mental Disorders in 204 Countries and Territories, 1990–2019: A Systematic Analysis for the Global Burden of Disease Study 2019. Lancet Psychiatry, 2022.
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