A new meta-analysis of published data, carried out by researchers at Ludwig Maximilian University of Munich (LMU), now provides a means of ranking the effectiveness of a range of current interventions.
The results of their investigation were recently been published in the online journal PLoS One.
The term dyslexia refers to a specific difficulty in learning to read and spell. It affects 5-10% of school children and although it is one of the most common learning disorders of childhood and adolescence, it also affects adults.
Indeed, the condition is often diagnosed relatively late. "Up to 40% of children who show signs of dyslexia also have psychological problems, which often result from discrimination provoked by their learning difficulties.
They are often confronted with comments such as: 'You're just too lazy' or 'You have to work harder'", says Prof. Schulte-Körne.
Furthermore, affected children and their families are often left to cope with the problem on their own, because nobody is responsible for providing support for them beyond the confines of the classroom.
Many popular 'therapies' are, at best, ineffective and some are downright bogus.
"Early intervention and appropriate therapeutic measures that take into account the specific nature of each individual case are urgently needed", says Prof. Schulte-Körne, pointing out that the curriculum offered in normal schools is often insufficient in helping children with severe dyslexia to overcome their disability.
"These children do not receive the necessary attention because school resources are inadequate and teachers are not sufficiently well trained to deal with the problem."
"More than 20 different 'treatment' methods have been developed which purport to help dyslexic children but in fact very few of them have any real effect," says Katharina Galuschka, who carried out the meta-analysis.
"Systematic training of the very basic process of relating the sound of a word to its orthographic form turns out to be particularly important."
The new study also shows that long-term interventions are significantly more effective than short-term training measures.
In addition, the study reveals that many popular methods which concentrate on single factors such as enhancing visual scanning of text, or improving auditory perception, are ineffective.
"Cognition-enhancing medication or the use of tinted lenses are also unable to improve the reading ability of dyslexic subjects."
"This the first meta-analysis of its kind and it provides a basis for formulating urgently needed guidelines for dyslexia treatment and therapy", Prof. Schulte-Körne explains.
He and his research group are now coordinating a set of medical guidelines for the treatment of dyslexia in Germany, due to be released shortly.
More information: Galuschka K, Ise E, Krick K, Schulte-Körne G (2014) "Effectiveness of Treatment Approaches for Children and Adolescents with Reading Disabilities: A Meta-Analysis of Randomized Controlled Trials." PLoS ONE 9(2): e89900. DOI: 10.1371/journal.pone.0089900