Introduction:

Autism was considered as a rare condition in the mid 1990s and now the prevalence of autism has increased. The question is whether the condition has truly increased or the awareness of the condition has increased. Many debates have been conducted on this and the reasons for increased prevalence are discussed. It could be due to the changes in diagnostic criteria, changes in diagnostic materials, increased awareness of ASD and also possibility of increased number of the children with autism. As far as now various environmental causes have been studied, yet none of them are confirmed by evidence based investigation. But there is strong evidence that the complex genetic factors play a critical role in the etiology.

The US Centre for disease control and prevention has conducted a National Health Interview Survey. From their survey, ASD is reported to occur in all racial, ethnic and socioeconomic groups. The survey which has done in 2000 shows 1 in 150 children were diagnosed as Autistic and the prevalence has increased to 1 in 59 children in 2014. Now it has been reported as 1 in 45. The survey also reveals that 31% of children with ASD were in the range of intellectual disability, 25% were borderline, 44% of ASD children were having an average IQ. A study published in 2018 says, about 1 in 100 children in India has at least one neurodevelopmental condition.

The prevalence data implicates the importance of early identification and intervention of ASD. The age of the children plays a critical role in the rehabilitation process and quality of their lives.The age of children has become an important aspect because of the 2 main contributing factors in the learning process; Brain Plasticity and Critical Period.

Brain plasticity is the ability of the brain to modify its connection. The neural connection will help to correct the small functional damages through making different neutral pathways. At birth, the child’s cortex has around 2500 synapses for each neuron. At the age of 2-3 years the number of synapses increases to about 1500 with respect to each neuron which mainly depends on the exposure to the environment and exploration skills of the child. Recognition of early signs of autism is important because reinforcement and repetitive activities which he/she has may learn. Thus the intervention is considered to enhance neural plasticity.

Critical period is considered as a lifetime period when our nervous system learns quickly from an environment of stimuli. So if the child gets enough exposure and intensive training during this time, it will reduce the difficulties of learning. Studies show that the first 3 years of life is the best time to give rehabilitation since it’s the period when rapid brain growth and organisation of cells happen. The stimulation which a child gets during this time will influence their language, social, emotional and motor skills. The children who are not getting early intervention give poor longer outcomes which also lead to financial stress. Early identification and intervention can also help in monitoring and preventing more adverse effects in overall skills. Thus it also helps to reduce the prevalence of developmental disorders.