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Transition to adulthood
The changing landscape
Patrick D. McGorry and Alison R. Yung
Introduction
Mental health difficulties are the key health issue faced by adolescents and young adults in the developed world today, with the incidence and prevalence of mental disorders being highest in the 15–24 year age group.1,2 Epidemiological studies have shown that 75% of all cases of mental illness begin before the age of 25, with most new onsets occurring in late adolescence and early adulthood.1 Young people between the ages of 15 and 25 years also bear the brunt of the morbidity associated with the onset of mental ill-health, with 55% of the burden of disease in this age group being due to mental disorders. Furthermore, cohort studies indicate that 50% of young people will experience a diagnosable mental disorder at some stage during the transition from childhood to adulthood.3 In line with international data, in Australia the prevalence of diagnosable mental disorders (including substance use) rises sharply from 9% before puberty to 19% afterwards,4 and peaks in the early twenties at over 26% in any given 12-month period.5
Despite these disturbing statistics that emphasise their obvious need, young people are often reluctant to seek help from mainstream health services. The Australian National Survey of Mental Health and Wellbeing indicated that 75% of young people aged 16–24 years with a 12-month diagnosis of a common mental disorder did not seek professional help for their symptoms, with this figure rising to 87% in young men.5 This is partly because our current health services are geared towards physical ill-health and are designed for children or independent adults, and they rarely cater for the specific needs of transition-age youth. Since young people are usually in good physical health, they often do not have a regular doctor, and when they do visit a general practitioner, they find it difficult to mention emotional concerns. Many factors contribute to this disengagement with our current health care system. These include poor mental health literacy, unhelpful beliefs involving personal strength and autonomy, and the level of their psychological symptoms. At a service level, issues of accessibility, confidentiality and cost, as well as the organisation of the services available, are critical barriers to accessing care for many young people.6
The impact of mental illness on young people
Mental ill-health in young people is all too often associated with ongoing disability, including impaired social functioning, poor educational achievement, unemployment, substance abuse, violence and victimisation, leading to a cycle of dysfunction and disadvantage that can be difficult to break.2,3 In Australia, the annual financial cost of mental illness in young people has been estimated to be $10.6 billion, with the bulk of this cost attributed to lost productivity due to lower employment, as well as absenteeism and premature death. This equates to $10,544 per annum per young person with a mental health disorder.7 These figures are likely to underestimate the true cost of emerging mental ill-health in young people as they do not account for school absenteeism and compromised educational achievement, which can have ramifications for future tertiary education and vocational pursuits.
An influential World Health Organization report on the global burden of disease estimated the peak age for the maximum negative social and economic impact of a disabling illness to be 22 years.8 This is because our society invests heavily in its young people to enable them to reach adulthood and become socially and economically productive in their turn, and therefore any disabling illness that prevents a young person from fulfilling their potential is a social and economic calamity.9 Mental disorder, precisely because its onset peaks in emerging adulthood and impacts on the most productive years of life, has recently been calculated to pose the greatest threat to the GDP of the developed and developing nations over the next 20 years, equal only to cardiovascular disease among the non-communicable diseases.10,11 Given the personal, social and economic costs of mental ill-health in young people, a strong focus on prevention and early intervention in this age group has the potential to generate greater benefits than intervention at any other time during the lifespan.
Why are young people so vulnerable?
There are complex biological, psychological and sociological reasons why young people are uniquely vulnerable to, and often heavily impacted by, the onset of mental illness. During early adolescence, the physical and hormonal changes of puberty, together with the brain maturational processes that take place at this time of life, create a biological ‘window of vulnerability’ to the onset of mental illness. This vulnerability is further accentuated by the increasingly complex demands from the young person’s social environment as they enter adolescence and begin the process of the transition to independent adulthood.
The activation of the hormonal systems that occurs during puberty has a significant influence on behaviour and emotional functioning. A sharp increase in the onset of depression, anxiety and substance abuse has been shown to occur around mid-puberty. In girls, pubertal stage predicts new cases of depression, as well as the persistence of depression. In boys, the rates of substance abuse, anxiety and conduct disorder all increase from early adolescence. Furthermore, children who enter puberty early have significantly higher rates of social and emotional difficulties. While much of this adolescent mental ill-health is relatively self-limiting, depression and anxiety tends to persist, with worry, obsessionality and anxiety being predictive of subsequent mental ill-health.12
Adolescence and early adulthood is a time of dynamic structural and functional change in the brain, driven by a series of maturational processes that result in the refinement of the neuronal circuitry, particularly in the frontal cortex.13 The increased capacity for abstract rather than concrete thinking that occurs during early adolescence, along with young people’s increased sensitivity to peer influence, creates a disjunction between their physical and intellectual maturity and their psychosocial maturity, which is exacerbated by the relatively slow maturation of the frontal cortex (see Chapter 2). This can be a source of considerable stress for young people and their families, as family and social roles must be renegotiated to accommodate the young person’s developing sense of autonomy.
The process of the transition from childhood to independent adulthood has changed qualitatively and quantitatively in recent decades, particularly in Western societies. During this phase of life, young people must complete the tasks of defining their individuality and autonomy, which includes establishing their own social networks, beginning sexual relationships, completing their education and moving into employment. Each of these processes can be challenging.
As our lifespan has increased, this developmental phase has been stretched and made less secure in many ways, largely due to the rapid pace of change in our social, economic and technological environments. Financial independence in the current economic climate is particularly challenging, as during economic crises, youth unemployment rises faster and recovers more slowly than general unemployment. In 2012, there were 7.5 million 15–24-year-old and 6.5 million 25–29-year-old economically inactive young people in the European Union. Youth unemployment is estimated as 10–20% globally.14 Thus this transitional phase of ‘emerging adulthood’ now often extends from prior to puberty into the late twenties before independent adulthood is securely achieved.15,16
Given the biological changes and sociological demands that young people must negotiate during the transition to adulthood, it is hardly surprising that mental illness, even when brief and relatively mild, can seriously disrupt this developmental trajectory and limit a young person’s potential.
Prevention, early intervention and youth mental health
Early intervention is particularly relevant in the context of youth mental health, precisely because young people are so vulnerable to mental health problems. Early intervention aims to prevent, or at the least delay, the onset of a serious mental illness and therefore avoid or minimise the associated damage to a young person’s social, educational and vocational functioning. Broadly speaking, preventive medicine relies on the concept of risk, and the availability of interventions to modify or counter the risk factors in question. In physical medicine, this concept has been widely adopted, and public health has benefited greatly from the proposal that preventive interventions – universal measures, selective measures or indicated prevention – could be targeted to particular population groups depending on an assessment of the risks, costs and benefits involved in each case.17 Since many of the causal and/or modifiable risk factors for the onset of mental disorders are not well known, psychiatry has been slower to adopt a preventive approach. However, researchers have proposed that subthreshold syndromes be regarded as risk factors for full-threshold disorders and that these subthreshold syndromes could be targeted by preventive interventions as a step towards indicated prevention for serious mental illness.18,19
Because it is so prevalent in young people,...
