Autism is a developmental disorder characterised by impairment of communication and social interaction, and stereotyped, restricted patterns of behaviour. The young child with autism fails to develop normal language and imaginative play. Autism (or autistic disorder) affects one in 1000 children and is the core disorder of a wider spectrum of pervasive developmental disorders. Australian paediatricians identify it as one of the more difficult areas of practice1 — there is still no cohesive explanation for the child's developmental arrest, and a plethora of therapies exist.

Diagnosis needs to be made by a multidisciplinary team. Parents then face a long list of possible interventions, and will usually be directed first to speech pathologists. Sensorimotor integration therapy (which stimulates or desensitises visual, auditory and tactile senses), and dietary interventions (eg, casein and gluten exclusion) are widely practised in Australia, but data for their efficacy are inadequate.2,3 A controlled trial of auditory integration (where the patient listens to music that has been computer modified to remove frequencies to which he or she is hypersensitive) showed no effect, yet it continues to be offered as a therapy.2 While ineffective therapies may be harmless, they waste parents' money and the child's valuable therapy time. Furthermore, the delay in implementing effective treatment may compromise the child's outcome.

Augmented communication, using visual modes such as pictures, symbols and signs, promotes communication and language in children with severe communication deficits and poor verbal imitation skills.4 However, the early intervention that has been subjected to the most rigorous assessment is behavioural intervention. There is now definite evidence that behavioural intervention improves cognitive, communication, adaptive and social skills in young children with autism. In 1987, Lovaas showed apparent recovery, persisting into adolescence, in nine of 19 young children who received an intensive home-based intervention based on applied behavioural analysis, a scientific method of reinforcing adaptive and reducing maladaptive behaviours.5,6 Subsequent studies also showed that behavioural intervention caused significant, albeit somewhat lesser, gains.7-11 This has modified the orthodox view that autism is always a severe, lifelong disability. Criticisms of the adequacy of the design and power of these studies are being addressed by the multisite Lovaas replication Early Autism Project. The first US site has released data (Wisconsin Early Autism Project).12 Again, after three to four years of intensive applied behavioural analysis intervention, about half the preschool children with autism acquired near-normal functioning in language, performance IQ and adaptability. Ninety-two per cent of intervention children acquired some language. Control children who received special education showed no gains in IQ or adaptability.12

Why is intensive applied behavioural analysis intervention more effective than special education for children with autism? This can not be simply explained by the intensity of these programs (30–40 hours per week). Children in a school-based Scandinavian study who received behavioural intervention gained an average of 25 language IQ points in the first year of the intervention, with improvements in performance IQ, communication and adaptability. On all scores, they surpassed control children who received special education according to best practice for autism, and the same intensity, duration and supervision of therapy.13

The superior outcome from behavioural intervention is thought to result from the targeting of specific deficits in autism that prevent learning: imitation, attention, motivation, compliance, and initiation of interaction. Skills are taught in small steps, mastered, and then generalised. Intensive, individualised one-to-one therapy is usually provided by students, behavioural therapists, or parents, under the supervision of behavioural experts. More natural settings of play and learning, augmented communication support, and other powerful visual learning tools, such as video modelling, may be used. Parents play a major coordinating role, and are trained to generalise the skills learnt by the child and to provide incidental teaching. Only positive reinforcement is used to teach the children.

Several preschool programs in the United States and the United Kingdom report comparable success to home-based behavioural programs. These programs have low child-to-staff ratios, collect detailed behavioural data, generally integrate the children with typically developing peers, and train parents intensively in behavioural methods.14

However, most young children with autism in Australia do not receive intensive behavioural intervention programs — partly because such programs are not recommended by many health professionals and partly because of their prohibitive cost for families. Only Western Australia has achieved partial government funding for preschool behavioural programs, as justified by a review by the Disability Services Commission of Western Australia.15 This State is also the first to have a prospective autism register, placing it in a unique position to provide Australian outcome data.

We are unaware of comprehensive Australian outcome data (from specialised preschools and schools for autism) with which to compare outcomes of applied behavioural analysis programs. For those of us who are parents of children with autism, this seems to be a pressing need. In the United States, parents have effectively advocated for evidence-based interventions using expert statements.2 If intensive behavioural programs in young children with autism allow about half of the children to no longer require special education and other costly interventions, government funding of such programs would provide economic returns in the long term. The returns to the children who respond and their families would, of course, be priceless.