Many research studies have documented the effectiveness of intensive behavior analytic interventions for autism. Howard, Sparkman, Cohen, Green, & Stanislaw, (2005) suggest that, “Findings from early intervention research indicate that intervention that is intensive, long in duration, and delivered directly to children (rather than caregivers) produces better outcomes than intervention that lacks those elements?. However, there is relatively little research on the effects of treatment intensity (hours per week) and duration (how many months or years intervention).
Ivar Lovaas (1987) demonstrated that children receiving 40 hrs per week (for at least 2 years) of intensive behavior analytic intervention made significantly larger gains than those receiving only 10 hrs per week. Furthermore, almost half of the children receiving intensive behavioral intervention achieved outcomes that placed them in the “normal” range of intellectual, communication, and adaptive functioning.
Eikeseth, Smith, Jahr, & Eldevik (2002) delivered behavioral intervention to 13 children with autism (ages 4-7 at beginning of study) for 28 hrs per week for 1 year. Seven of the 13 children (58%), at follow up, achieved scores in the normal range for functioning.
Howard and colleagues (2005) provided 25-30 hrs/week for children under age 3 and 35-40 hrs per week for children over age 3. They also included two control groups. One group received “eclectic”” intervention (i.e. TEACCH, some DTT, and sensory integration) in a non-intensive (15 hrs per week) community special education program and one receiving regular special education (30 hrs per week). After 14 months, various outcome measures were substantially and statistically significant for the behavior intervention group but not for either of the control groups. Therefore, the results of this study (and others) demonstrated significant improvements in intellectual functioning, communication skills, and adaptive behavior as a result of behavioral intervention. These gains were larger than those reported by Anderson, Avery, Dipietro, Edwards, and Christian (1987) for preschool children with autism who received behavioral intervention for 15-25 hrs per week for one year.
The intensity of behavioral intervention is important for accelerating a learner’s acquisition rate beyond the normal rate in order to close the gap between the learner’s skills repertoire and his/her typically developing peers. However, it is unlikely that this gap will be closed within one year’s time. This means the duration of intervention will often be 2-3 yrs or more. In the “best case” scenario, this gap will be closed and the learner will function at the same level as his/her peers. However, research indicates that fewer than half of children receiving a competently delivered behavioral intervention program will achieve this level of functioning. Regardless, for most children, the gap will continue to be closed as a result of behavioral intervention.
On the other hand, at least 2 published studies (Eikeseth et al., 2002 & Howard et al., 2005) have demonstrated that equally intensive alternative or eclectic treatments DO NOT yield comparable results. Worse yet, it is projected that learners in such programs would continue to lose ground to their same aged peers if they continue in such programs.
So, back to the question we started with… what is the recommended number of hours per week? Currently, we don’t have adequate research to answer this question on a student-by-student basis. However, the literature tends to supports intensive behavioral intervention (i.e. 20-40 hrs per week). In addition, certain learner characteristics need to be considered. For example, learners who are 2 yrs old and those who are 5 yrs old will have differences in the number of hours per week that they can successfully handle.
Generally, more seems to be better. But it is important to note that behavioral intervention continues beyond the number of 1-on-1 “therapy hours”. The goal is to create a 24 hr/day 7day/wk (24/7) therapeutic environment. This means actively including parents during “down time”. Assuming 12 hrs of sleep per day, there are nearly 90 waking hrs per week. This means more time with parents than interventionists, even if receiving 40 hrs per week of intensive intervention.