Can a young child (under age 6) be diagnosed with dyslexia or at that age is the focus on recognizing warning signs?

This is an excellent question. Whether children can be identified early (under age 6) and treated for dyslexia depends, in part, on whether we consider the symptoms of dyslexia to be “expected” or “unexpected” in a child. The International Dyslexia Association (Lyon et al., 2003) defines dyslexia as a specific learning disability that is neurological in origin. It is characterized by difficulties with accurate word recognition, fluent word recognition, or both, and by poor spelling and decoding abilities. These difficulties typically result from a deficit in the phonological component of language that is often unexpected in relation to other cognitive skills and the provision of effective classroom instruction.

If we consider dyslexia to be an “unexpected” difficulty in a child’s ability to develop word reading and spelling skills then identification is typically operationalized by the presence of a significant discrepancy between a child’s word reading and spelling achievement and other cognitive skills, often measured via an IQ test. This identification practice requires a child to fall significantly below their potential and that of peers on word reading, spelling, or both before they can be identified as having dyslexia.  This is often referred to as a “wait-to-fail” model of identification.

However, if dyslexia is defined as an “expected” difficulty, based on neural-cognitive processing deficits underlying reading and spelling development, we can move away from discrepancy-based definitions of dyslexia and focus on early identification and treatment of children with dyslexia either prior to the onset of formal reading instruction or soon after instruction is initiated. This allows for early evidence-based intervention for reading problems to be initiated in the primary grades before children with dyslexia fall behind their peers.

The challenge with early screeners or assessments for dyslexia is that in order to detect the subtle early signs of dyslexia, they tend to over identify children as at risk (i.e., false positives). False positives occur when children score poorly on a dyslexia screener but still develop typical reading and spelling skills. This is because measures of phonological processing and early print awareness, often used to identify children with dyslexia prior to reading instruction, are confounded by a child’s linguistic and cognitive development as well as opportunities and experiences to learn. While cognitive psychologists and neuroscientists continue to identify important behavioral and neuro markers associated with dyslexia to reduce the number of false positives when screening children under 6 years of age, current false positive rates are unacceptably high. To decrease false positives associated with early screening for dyslexia, it is often recommended that diagnosis for dyslexia take place after children have had some experience with learning to read. However, this practice again tends to delay the opportunity for early intervention before children begin to fail.

A different way to think about dyslexia in young children is to use multiple indicators and a multi-level approach to gauge a child’s risk for dyslexia. This would take into account important linguistic and cognitive developmental milestones along with other important factors such as family history of dyslexia to identify different levels of risk. In such an approach, children with multiple risk factors would be considered at greater risk for developing dyslexia and therefore should receive intensive evidence-based intervention before or simultaneously with the onset of formal reading instruction. Those with fewer indicators and less elevated risk should be monitored closely to gauge their response to classroom instruction. This allows intervention to proceed before the diagnosis of dyslexia but certainly should not take the place of a thorough diagnostic evaluation for dyslexia.

References

The International Dyslexia Association. (2014). IDA dyslexia handbook: What every family should know. Baltimore, MD: The International Dyslexia Association.

Lyon, G.R., Shaywitz, S.E., & Shaywitz, B.A. (2003). A definition of dyslexia. Annals of Dyslexia, 53, 1–14.