About 13% of children and adolescents have a mental illness
The mental health, or more precisely ill-health, of children and young adults has been in the news this year. The (London) Times ran a mental health campaign in which youth mental health figured prominently. But arguably the most important publication on this topic this year is a systematic review of 41 studies including 87,742 people around the world by Palnczyk and colleagues which found that 13% of all children and adolescents have a diagnosable mental illness that is impacting on their day to day functioning. At any point in time anxiety states affect about 6% of our children, depression and ADHD about 3% each, and conduct disorder 2%. These rates are higher in the USA and in people aged 12-18, but this is not a ‘first world’ or transient problem.
Impact – The World Health Organisation, in their Global Burden of Disease Study, found that neuropsychiatric disorders were the main cause of burden in high-income countries, especially in those aged 15–24 years, but the burden from these disorders was also high in low-income and middle-income countries. Indeed, three of the top four causes of disability (DALYs) world-wide in young people aged 10-24 years are Depression (at no.1), RTAs (no.2), Schizophrenia (no.3) and Bipolar disorder (no.4), with alcohol and self-inflicted harm not far behind.
‘Half of all lifetime cases (of mental illness) start by age 14 and three fourths by age 24 years.’
Outcomes – These problems are not transient either. Some will spontaneously resolve, but adverse consequences of (untreated) mental illness in childhood are the norm. For example, in another key paper published this year, the evocatively named ‘Great Smoky Mountains Study’ found that children with a psychiatric disorder were about six times more likely to end up with one or more adverse adult outcomes (such as criminality, addiction, suicidality, teenage parenthood, health problems and premature death) than those without. These associations persisted even after statistically controlling for childhood psychosocial hardships and adult psychiatric disorders.
Treatment – As ever with mental ill-health, only a minority of affected youths who could benefit from treatment actually get it. A recent household survey in the USA found that the percentage of youths receiving any outpatient mental health service increased from 9% in 1996-1998 to 13% in 2010-2012, by when it was about 44% in those with more severe mental health impairment. So, things are improving but it is still only a minority who get any treatment at all.
Mental ill-health is common and disabling in children and adolescents all over the world, and tends to have adverse effects unless treated. The high frequency of mental disorders in our youth and their associated negative consequences means that they should be health priorities.
 Bennett R, Burgess K. True scale of child mental health crisis uncovered. The London Times Thursday March 12 2015, page 1.
 Polanczyk GV1, Salum GA, Sugaya LS, Caye A, Rohde LA. Annual research review: A meta-analysis of the worldwide prevalence of mental disorders in children and adolescents. J Child Psychol Psychiatry. 2015 Mar;56(3):345-65. doi: 10.1111/jcpp.12381. Epub 2015 Feb 3. http://www.ncbi.nlm.nih.gov/pubmed/25649325
 Gore FM, et al. Global burden of disease in young people aged 10–24 years: a systematic analysis Lancet 2011; 377: 2093–2102. http://www.ncbi.nlm.nih.gov/pubmed/21652063
 Kessler RC, Berglund P, Demler O, Jin R, Merikangas KR, Walters EE. Lifetime prevalence and age-of-onset distributions of DSM-IV disorders in the National Comorbidity Survey Replication. Arch Gen Psychiatry. 2005; 62: 593-602. http://www.ncbi.nlm.nih.gov/pubmed/15939837
 Copeland WE, Wolke D, Shanahan L, Costello EJ. Adult Functional Outcomes of Common Childhood Psychiatric Problems: A Prospective, Longitudinal Study. JAMA Psychiatry 2015; 72: 892-9. http://www.ncbi.nlm.nih.gov/pubmed/26176785
 Olfson M, Druss BG, Marcus SC. Trends in mental health care among children and adolescents. N Engl J Med 2015; 372: 2029-38. http://www.ncbi.nlm.nih.gov/pubmed/25992747