Children and adolescents constitute almost a third (2.2 billion individuals) of the world’s population of these, almost 90 % live in low-income and middle-income countries, where they form up to 50 % of the population (UNICEF 2008). Almost 20 % of all children and adolescents are affected by mental health problems and at least half of these show impaired schooling and social development (Sawyer et al. 2000). Among children and adolescents, problems such as child abuse and neglect, conduct disorder, alcohol and drug abuse, depression, ADHD, and suicide are all becoming more common than they were initially thought to be (Rutter and Smith 1995; Costello 1998). Furthermore, mental disorders (notably depression) are appearing at a younger age, and they also seem to be increasing in severity (Mrazek and Haggerty 1994). Children and adolescents with mental health problems are twice as likely to report feeling ‘very stressed’, three times more likely to have poor or fair physical health, three times more likely to perform below grade level at school, three times more likely to use alcohol and other drugs, and six times more likely to think about killing themselves (Zubrick 1995; Costello 1989).

Although most of child and adolescent psychiatry is practiced in industrialized countries, the vast majority of the world’s children live in the developing world. The mental health of children in developing countries is important, but a relatively under-explored area. Methodological problems of epidemiological studies in this field include, in addition to other factors, the use of case definitions and disability criteria developed in the West and the assumption that dimensions of disorder and thresholds for reporting problems are similar to European and North American populations.

Psychiatric epidemiological studies from high-income countries indicate that more than a quarter of children and adolescents meet lifetime criteria for a mental disorder (Srinath et al. 2005); about 10 % have distress or impairment that is severe enough to warrant intervention (Brauner and Stephens 2006). Children and adolescents in low- and middle-income countries (LAMIC) constitute 35–50 % of the population. Although many studies report that the burden of child and adolescent mental health poses a significant public health burden, the major challenges are meager resources and manpower, low recognition, lack of much needed policy making, low priority for fund allocation, as well as limited research. For example, mental health research in child and adolescent mental health contributes barely 3–6 % of all published mental health research in the world (Patel and Sumathipala 2001; Saxena et al. 2006, 2007).

India is a developing country with a population of more than 1 billion (which is 16 % of the world population), and children below 16 years of age constitute more than 40 % of its population. India presents a unique case, not only in terms of this big volume of child and adolescent population, but also in terms of its immense diversity in the languages spoken, levels of literacy, and social and cultural practices, including the child-rearing practices. Despite our strengths in terms of great tradition and culture and above all abundance of family support, on downside, we have low budgetary resources, interference from competing and conflicting healing systems, scarcity of mental health personnel, ‘brain drain’, and the stigma against seeking help for problems related to the mental illnesses. In the developed world application of methodological developments such as structured and semistructured diagnostic interviews, statistical methods for estimating prevalence and correlates of mental disorders have established the prevalence of mental disorders, patterns of co-morbidity, correlates and risk factors for mental disorders, and service patterns. In contrast, Indian studies have not as yet definitively and consistently established epidemiological data on mental disorders in children and adolescents. Some notable studies are outlined below:

Attempts at estimating the burden of child and adolescent psychiatric disorders in India have only consisted of a few methodologically sound studies among community samples. These have reported overall point prevalence rates of 9.4 % in children aged 8–12 years (Hackett et al. 1999), 12.5 % in children aged 0–16 years (Srinath et al. 2005), and 1.81 % in adolescents aged 12–16 years (Pillai et al. 2008). In a study from North India (Malhotra et al. 2002a), the prevalence rate of psychiatric disorders in the age group of 4–11 years was found out to be 6.33%; in this sample, enuresis was the most common disorder. In the first ever study on the incidence of child psychiatric disorders in India (Malhotra et al. 2009), which followed up children after 6 years, the research team that included this author reported that the incidence of psychiatric disorders in a representative sample of school children from Chandigarh was 18 per 1,000 per year.

Prospective studies tracking the natural course of specific childhood and adolescent mental disorders have not been conducted in Indian community samples. In a recent review (Malhotra and Pradhan 2013), the authors concluded that the prevalence and incidence rates found in the Indian studies are lower than those reported in developed countries; however, further studies clarifying the reasons for these lower rates are needed. The epidemiological data described below are taken from an editorial specifically addressing this issue (Sharan and Sagar 2008).

Externalizing disorders: The median prevalence rate of ADHD in studies conducted in the developed countries is reported to be 4 % (range: 1.7–17.8 %). However, in some Indian studies, the point prevalence estimate for hyperkinetic disorder is 1.6 %. In one such two-stage study, which specifically assessed ADHD, a prevalence of 12.2 % in preschoolers selected from kindergartens was reported. The median 12-month prevalence rate of disruptive behavior disorders (i.e., conduct disorder or oppositional defiant disorder) is 6 % (range: 5–14 %) in studies conducted in developed countries, whereas one Indian study has reported a point prevalence for conduct and oppositional defiant disorder to be 1.3 %. A school-based study from India (Shenoy et al. 1998) showed that the prevalence of externalizing disorders is higher among boys; however, a definitive statement regarding gender distribution of externalizing disorders awaits replication in community samples.

Substance abuse and dependence: The median estimate of alcohol or drug abuse or dependence in community surveys of adolescents in developed countries is 5 % (range: 1–24 %). The complete absence of substance abuse in a sample from Bangalore, India (Srinath et al. 2005) was linked to the low response rate for the diagnostic interview, youths’ unwillingness to reveal such information, and parents’ ignorance about the abuse.

Learning disorders: A study in rural India found that more than 80 % of the 172 children in a group of dropouts suffered from learning disability, as diagnosed by a psychological screening test (Pratinidhi et al. 1999). A survey of 1,535 primary school children drawn from schools in Bangalore city found that 15 % suffered from learning disability. Learning problems were associated with a low quality of academic work, poor concentration, not carrying out tasks, low motivation, and under-achievement (Shenoy et al. 1998).

Disorders in very young children: With the exception of pervasive developmental disorders, there has been considerable controversy about the validity of diagnosis of mental disorders in very young children (age < 5 years). Egger and Angold (2006) summarized the rates of childhood mental disorders as follows: ADHD (2–5.7 %), oppositional defiant disorder (4–16.8 %), conduct disorder (0–4.6 %), depression (0–2.1 %), and anxiety disorders (0.3–9.4 %). There was a high degree of co-morbidity in young children with mental disorders; of those with one disorder, approximately 25 % had a second disorder. The proportion of children with co-morbidity increases about 1.6 times for each additional year from age 2 (18.2 %) to 5 (49.7 %) years. In contrast, Srinath et al. (2005) reported that the most common diagnoses in the 0–3 year age group were pica (2 %), behavior disorder NOS (1.8 %), expressive speech disorder (1.4 %), and mental retardation (now called ‘intellectual disability’, 1.4 %).

Childhood sexual abuse: There are very few reports on child sexual abuse, from developing countries. In a study of school-based adolescents in India, 6 % reported a lifetime experience of coercive sexual intercourse; other types of sexual harassment and abuse were commonly experienced, and sexual abuse was strongly associated with educational failure, poor physical health, and mental health (Patel and Andrew 2001).

To treat a child from a developmental perspective was known even to people of ancient India as evidenced by the clear writings in the Kashyapa Samhita (an ancient treatise of Ayurveda, meaning ‘collections of the sage teacher Kashyapa’), the entire writings of which are devoted to childcare. Kashyapa Samhita describes 46 disorders out of which 12 are described as disorders of children (bala roga). Quite in tune with the modern models of ‘integrated maternal and child mental health’, in ancient India, the mother and infant were seen as a single unit. The central themes in the Kashyapa Samhita are not only the concept of mother–child unit, but also the ‘developmental stage model,’ which describes the various stages of physical as well as psychological stages of development of the child from conception till adulthood. In addition, this system of child care was in perfect accordance with Mother Nature. For example, a baby was taken out to see the moon in the 3rd month and the sun in the 4th month after its birth; the molding of the front portion of the head (Chuda karana) was done around the 6th month to ensure proper fontanel closure; ear piercing was done around the 1st year of the child, the thread ceremony (Upanayana, meaning child is cognitively developed enough (a similar ceremony in Christian culture in the West is called Communion) is performed around the age of 7 years (which is amazingly in accordance with the modern studies in cognitive development by theorists such as Piaget and others that at age of 7 years, a child achieves preliminary logical thinking). Devoted readers can refer to the story of Jivaka (Vriddha Jivaka Tantra, i.e., the doctrines of old Jivaka Srikrishnamurthy 2002) for further details.