Neuropsychol Rev (2008) 18:339–366 Can Children with Autism Recover? If So, How?
Molly Helt, et al .......Department of Psychology, University of Connecticut.......
Abstract
Although Autism Spectrum Disorders (ASD) are generally assumed to be lifelong, we review evidence that
between 3% and 25% of children reportedly lose their ASD diagnosis and enter the normal range of cognitive, adaptive
and social skills. Predictors of recovery include relatively high intelligence, receptive language, verbal and motor
imitation, and motor development, but not overall symptom severity. Earlier age of diagnosis and treatment, and a
diagnosis of Pervasive Developmental Disorder-Not Otherwise Specified are also favorable signs. The presence of
seizures, mental retardation and genetic syndromes are unfavorable signs, whereas head growth does not predict
outcome. Controlled studies that report the most recovery came about after the use of behavioral techniques. Residual
vulnerabilities affect higher-order communication and attention. Tics, depression and phobias are frequent residual
co-morbidities after recovery. Possible mechanisms of recovery include: normalizing input by forcing attention
outward or enriching the environment; promoting the reinforcement value of social stimuli; preventing interfering
behaviors; mass practice of weak skills; reducing stress and stabilizing arousal. Improving nutrition and sleep quality is
non-specifically beneficial.
In this fascinating analytical review of the scientific literature in autism, the authors examined empirical evidence that some people with autism “recover” and no longer meet the diagnosis of autism. The general view in the scientific community has been that autism is a life-long condition and that treatment interventions are most often designed to 1) minimizing maladaptive symptoms (e.g., self-injurious behaviors) and 2) maximizing cognitive/behavioral/social functioning (e.g., increasing adaptive social behaviors or language). But what happens when these interventions are sufficiently effective in minimizing or eliminating symptoms to the extent that the person no longer meets the DSM-IV criteria for autism? Has the person recovered?
The authors first provided a specific working definition of “recovery” before embarking on an exploration of the available literature. The authors argued that to be considered “recovered” a person:
1. has a clear history of autism
2. must be learning and applying skills at a developmental level that is within the range expected in typically developing persons of the same age.
3. must not meet DSM-IV symptom criteria for ASDs
Based on their current research program, they further expanded this definition to include a more detailed set of criteria, namely, a “recovered” person:
1. must not meet ASD cutoff on social or communication domain on the ADOS
2. must not receive special education services targeted to remediate key features of autism (if any special education services are received they must target non-autism features such as attention, learning disabilities, etc)
3. must be functioning within a regular education classroom WITHOUT individualized assistance
4. IQ must be 80 or greater
5. Vineland communication and socialization scales must be within the normal range (78 or above)
A critical component of this definition of recovery is that it is not limited to DSM-IV based symptoms of autism, but it also addresses key areas of functioning. This is critical, because it prevents using the label of ‘recovered’ in cases when the effects of the treatment are limited to reducing symptoms, with little change in the functional limitations of the condition.
The authors then conducted a narrative review of the available scientific literature and concluded that there is compelling evidence showing that between 3% and 20% of children diagnosed with autism may eventually meet the criteria for “recovered”. This wide range is likely the result in differences between the studies in the nature of the population examined, and the presence or absence of factors that are believed to contribute, or hamper, the possibility of recovery. That is, the authors also found that a number of baseline factors (i.e. present while the person met diagnostic criteria) facilitated recovery rates, including:
1. high intelligence
2. presence of receptive language
3. verbal and motor imitation
4. early age of diagnosis
5. PDD-NOS diagnosis
A number of factors limited the possibility of recovery, including:
1. seizures
2. mental retardation
3. genetic syndromes
限制康复的因素包括
1。 癫痫
2。 智障
3。 遗传综合症、
Although these findings are interesting, I believe an additional contribution of this study is their presentation of the possible mechanisms by which treatment interventions may lead to recovery in autism. These mechanisms can be seen as a road map that helps parents, educators, and clinicians better understand how treatment modalities can be targeted to the specific deficits of each child. These mechanisms include:
1. Normalizing input through attention
2. Promoting the reinforcement value of social stimuli
3. Early intervention provides enriched environments
4. Early intervention provides mass practice and trials
5. Compensatory processes
6. Suppression of interfering behaviors
1. Normalizing input through attention
The general concept here is that some of the deficits in autism are due to limitations in attention or distraction that limits the child’s exposure to key stimuli (language, eyes, faces) that are critical for normal development. By redirecting the child’s attention to key stimuli via specific treatment interventions (e.g., ABA), it may be possible to help the child return to a more typical developmental trajectory.
2. Promoting the reinforcement value of social stimuli
This mechanism assumes that we are social because we are rewarded for being social. It is possible that children with autism lack the ability to experience internal rewards from social interactions, thus limiting the occurrence of such behaviors. By promoting such reinforcement (providing external rewards) we may be able to increase social behaviors by fostering the natural reinforcing properties of such behaviors
3. Early intervention provides enriched environments
Whether as the result of attention/distraction difficulties, or problems with the mechanisms that control the feelings of reward we experience during social interactions, one theory of autism suggests that limited environmental input contributes to the development of autistic symptoms. For example, children exposed to severe sensory deprivation (such as children in Eastern European orphanages), are at an increased risk for developing autism symptoms. Animal models have also shown that environmental deprivation leads to disruption in typical development, especially in the social realm. Therefore, early interventions may increase environmental sensory exposure (“enriched environmental opportunities”) facilitating a return to typical developmental trajectories among some children.
4. Early intervention provides mass practice and trials
This mechanism is based on the concept of neuro-cognitive rehabilitation. That is, that intensive repetition facilitates recovery of brain function, likely by facilitating the creation of new neural pathways. Therefore, this mechanism assumes that autism is at least partially due to problems during neural development that leads to an atypical neural organization. The mass repetition provided by intensive intervention would facilitate the development of new neural connections that normalize neural functioning, leading to a decrease in symptoms and neuro-cognitive deficits.
5. Compensatory processes
Similarly to #4, this mechanism suggests that even when brain organization can not be changed (as in irreversible brain damage), early intervention can lead to the development of compensatory behaviors or mechanisms that help the child “bypass” the original deficits. A simple example in physical rehabilitation is the case of right-handed person that suffers a stroke and loses functioning of his right hand. This person may, via intensive training, learn how to write well with his left hand, therefore compensating for the original deficit. In the case of autism, an example would be the case of implicit vs. explicit recognition of emotional facial expressions. Typically developing kids implicitly recognize facial expressions without necessarily needing to “break down” the components of such facial expression (e.g., shape of mouth, tears, etc). However, children with autism may have a deficit in this implicit system, but may learn to compensate for this deficit by developing explicit strategies (e.g., tears most often means sad) that would result in the same outcome: recognition of facial expressions.
6. Suppression of interfering behaviors
This is conceptually related to #1. Early interventions lead to suppression of behaviors that interfere with attentional focus to key environmental stimuli. For example, repetitive behaviors limit environmental input to usually one key non-social stimulus. Treatment interventions that reduce repetitive behaviors also result in an increase in behaviors that facilitate typical brain development, such as social interactions.
7. Limiting stress and arousal
Also conceptually related to #1 and #6, this mechanism indicates that early interventions reduces emotional arousal facilitating attentional focus to key environmental stimuli and also preventing the damaging effects of exposure to chronic stress.
和1和6相关
8. Boosting recovery via biological treatments
Finally, biological interventions may facilitate recovery by enhancing the effects of the previously described mechanisms. For example, anti-anxiety medications may lead to a reduction of stress and arousal, thus facilitating the effectiveness of other behavioral interventions in promoting attentional focus, compensatory mechanisms, etc.
A final comment, please note that the mechanisms described above are simply the authors’ interpretation of what could be the underlying mechanisms for recovery. Although there is evidence to support these processes, these are entirely theoretical mechanisms, and the research on their validity is ongoing.