Notable Fraction of Children in India May Have a Neurodevelopmental Disorder

National registries, which don't exist at the moment, should ideally bear the burden of surveying and recording the prevalence of these disorders.

A significant number of children in India between the ages of two and nine years may be affected by at least one type of neurodevelopmental disorder (NDD), suggesting the presence of significant – yet often overlooked – public health issue.

As the human body grows, the central nervous system develops as the product of a complex relationship between genes, brain processes and emotional and behavioural mechanisms. The environment and other related factors, such as childhood diseases and nutrition, disturb this dynamic process and can prevent the brain and the nervous system from functioning as usual.

Some of the consequences include autism spectrum disorders, speech and communication-related disorders, Down’s syndrome, cerebral palsy and behavioural issues. Generally, those affected can have their social acceptance, economic independence and productivity compromised without timely rehabilitative interventions.

“Neurodevelopmental disorders are a huge problem [in India],” said Pratibha Singhi, director of paediatric neurology and neurodevelopment at the Post Graduate Institute of Medical Education And Research, Chandigarh. “Parents often miss them” and “professionals also miss them,” she added. Unless we have a good system in place it is very difficult to pick up these disorders.

Scientists have paid increased attention to these disorders in the last few decades in an effort to understand their causes and progression better and mitigate risks.

One report by the WHO states that about one in six children in industrialised nations may have behavioural intellectual disorders such as cerebral palsy, autism and developmental delays. Although the rise in incidence can be explained by increased awareness, there is also some concern that there might be an actual increase in the prevalence of such disorders. Decision-making in this context has been further hampered by a lack of accurate data, in turn slowing policy response to help reduce the burden.

Tackling NDDs early on is important because the brain’s plasticity – its ability to change – is highest in the first five years of life. If these disorders are left unattended, it becomes difficult to manage those affected children later on, according to Singhi. “In our country, we don’t have any registries for disabilities, neurodevelopmental disorders or anything like that, and if you have to provide any remedial measure, you first need to know the [size] of the problem, and only then you can move ahead.”

There are a large number of known risk factors for NDDs, including location of delivery, delayed crying or difficult breathing at birth, infections requiring hospitalisation, brain infection and prematurity. These factors contribute to almost half of all cases of NDDs.

“Importantly, most of these factors are modifiable with better health services for mother and children,” Narendra Arora, executive director of the INCLEN Trust, said. These risk factors are widespread. Therefore, it is expected that there could be a large proportion of children in India who could be afflicted. However, data from the ground is missing.

A new study produced by 56 researchers from India and the US, and published in July this year, provides just this glimpse. The team developed culturally sensitive diagnostic tools for autism, epilepsy, attention deficit hyperactivity disorder (ADHD) and neuromuscular impairment. Using these tools, they assessed 3,977 children between two and nine years of age for nine different NDDs across five regions in India. The sampling sites ranged from rural areas, such as Palwal in Haryana and Dhenkanal in Odisha, to all urban Hyderabad. Once the data was collected, they used statistical tools to analyse the numbers.

The results indicated that it was likely that about 11-13% of all children in India have at least one form of NDD; of them, 21.7% likely had at least two types of disorders (both numbers at the 95% confidence level). The most common types of disorders included hearing impairments, intellectual disabilities, speech and language disorders, epilepsy and learning disorders. There was no significant difference in prevalence for different socioeconomic statuses, situation in rural or urban regions or by geographical location.

Prevalence estimates of NDDs for the five study districts according to age categories. Source: PLOS

Prevalence estimates of NDDs for the five study districts according to age categories. Source: PLOS

Although tribal regions did show a lower prevalence, it is possible this was because children with NDDs did not survive for long. There was also a difference in the distribution of NDDs across different sites. In the north, where greater middle-ear infections were reported, hearing impairment was higher, whereas learning disabilities were higher in North Goa. “In other words, it is not geography but the local prevalence of risk factors,” Arora, who was lead author of the published paper, said.

“The study provides robust evidence that NDDs in Indian children is [a] significant public health problem and necessitates adequate investments,” he added. Such evidence can help add to schemes such as the Rashtriya Bal Swasthya Karyakram, which does address all the NDDs covered in the study.

Singhi, who was not involved in the study, wasn’t surprised by the findings and thought in fact that they provided a good representation of the problem. She also said the study was a good attempt given the scale at which it was conducted – although some limitations created as a result.

For example, she expressed concerns about the person administering the tools in the field and how good that person might have been at identifying various disabilities, particularly so in a population as heterogeneous as the one in India. This in turn could precipitate large variation in the data.

According to her, national registries should ideally bear the burden of surveying and recording the prevalence of NDDs, and that their numbers are also likely to be more accurate. “When we talk about prevalence in India, it is a guesstimate, at best an estimate,” Singhi said. “At least [the study] sensitises people so that the government and other health agencies can take up the cause.”

Lakshmi Supriya is a freelance science writer based in Bengaluru.