THE "BIG PICTURE" OF
Lars Perner, Ph.D.
Introduction. It is hoped that this essay will not only provide the reader with useful background information, but will also help organize impressions from other sessions and relate points made by speakers to those made by others. This review briefly discusses emerging insight on a number of issues in autism, suggesting how many phenomena are in fact related. It is hoped that this discussion will help create a “roadmap” for the study of autism
The following areas will be discussed:
Diagnosis and diagnostic categories: It is not the purpose of this paper to dwell on diagnostic standards and the distinctions between very subtypes of autistic spectrum disorders (also known as pervasive developmental disorders). Although diagnosis has significant implications for services eligibility and health care resource allocations, it appears that the differences among individuals with the same diagnosis are often greater than average differences from those in other diagnostic categories. Further, the same individual will often receive different diagnoses at different points in their lives.
It should also be noted that while diagnostic standards are constantly being reevaluated, many are inherently quite arbitrary. The Diagnostic and Statistical Manual (DSM) IV of the American Psychiatric Association, for example, bases a diagnosis on whether an individual appears to fit a certain number of symptoms in one category simultaneously with meeting a different number of criteria on a different list. One criterion that is used to distinguish between individuals with Asperger’s Syndrome and Autistic Disorder is whether the individual had “clinically significant delay” in using language. A recent paper by Dr. Luke Tsai has questioned the usefulness of this criterion.
There is considerable disagreement as to the strictness of the criteria that should be used to diagnose autistic spectrum conditions. For example, the standards developed by the Swedish researcher Christopher Gilbert identify significantly more individuals than those of the DSM IV.
There are three main diagnostic categories within the autistic spectrum:
§ Autistic Disorder. Generally, this is the more severely challenged population. Although intelligence levels vary tremendously within the group, a large number of individuals with this diagnosis score in the mentally retarded range on IQ tests.
§ Asperger’s Syndrome: This group often shows symptoms similar to those with autistic disorder in areas such as withdrawal, lack of interest in interacting with others, dislike of change, over-sensitivity to touch, sounds, and smell, and impairment in non-verbal communication. In practice, this label is often used more generically to refer to higher functioning individuals. While this group is often less impaired in terms of speech, there is often a tendency toward the use of very formal (“pedantic”) speech and a tendency toward very literal interpretation.
§ Pervasive Developmental Disorder—Not Otherwise Specified (PDD-NOS). This diagnosis really is as vague as it sounds, but it actually serves a useful purpose. The way that autism is manifested in different individuals varies tremendously, and the official diagnostic criteria of the DSM IV are somewhat arbitrary. It is possible for someone who is clearly affected to “slip through the cracks” of DSM IV, and this diagnosis allows the identification of such individuals based on more flexible criteria. Unfortunately, individuals diagnosed with PDD-NOS are often not eligible for as many benefits as those diagnosed with autistic disorder.
Two other diagnoses—Rett’s Syndrome, found only in girls—and Childhood Disintegrative Disorder (CDC)—are less common. Rett’s Syndrome is often associated with a premature stop to growth of the head and a loss of skills that were previously mastered. CDC is a rarely used as a diagnosis. As the name suggests, the child will develop normally up to a point after which many skills are lost. Unlike Rett’s Syndrome, CDD may not be as clearly traceable to specific physiological factors.
Because eligibility for services differs in many jurisdictions based on the specific diagnosis, it is believed that many professionals may “stretch” diagnostic criteria in some situations. For example, an individual diagnosed with autistic disorder is often eligible for more programs—whether special education or vocational training—than one diagnosed with Asperger’s Syndrome.
Paradoxes of autism: Autism is a condition that continues to perplex even those who have been involved in the field for years. The term “pervasive developmental disorder,” as the autistic spectrum is called in the American Psychiatric Association’s Diagnostic and Statistical Manual (DSM) IV, warns us of the very wide span over which autism influences a person’s life. To complicate matters, it has long been recognized (e.g., Frith 1991) that autism is a highly paradoxical phenomenon. In fact, some individuals with autism (IWAs) will show symptoms that seem to be diametrically opposite to those experienced by others (e.g., some excel in spatial ability, while this is an area of significant impairment for others). Because much work in autism has centered on either specific problem areas or the experiences of a subset of the affected population, it is often difficult to piece together seemingly ill fit parts of the puzzle in order to see a “big picture.”
One way to understand seeming contradictions within autism is through the metaphor of El Niñofication. Back in 1997-98, weather patterns on the American continents experienced a great deal of turbulence. There were frequently more rain storms, and temperatures were often significantly higher than they would normally be during the respective seasons. However, at other times—and quite unpredictably so—weather patterns went in the opposite direction because the fundamental weather patterns were destabilized. Because brain structure tends to differ in IWAs, it is not surprising that very complex differences can result. The fact that some people on the spectrum excel in some areas (such as verbal or spatial abilities) while others are highly challenged can be explained in part by the priorities assigned to different functions within the brain.
Causes and genetics. It is by now becoming very evident that autism is, to a very large extent, controlled by genetic factors. The picture is complicated in that several genes or gene regions appear to be involved. Currently, all specific genes responsible for autism have not been identified, and there is considerably uncertainty about even the number of genes involved. Although some of the suspected genes are implicated in other conditions such as ADHD, there is considerable uncertainty as to which aspects of autism may be controlled by different genes, alone or in combination. Rapid progress is being made in this area, however.
It is quite clear that autistic spectrum disorders tend to run in families. Different individuals in the same family may have different specific diagnoses (e.g., PPD-NOS, Asperger’s, or Autistic Disorder), and family members of diagnosed individuals may show symptoms clearly consistent with the autistic spectrum while not quite meeting the “threshold” for a diagnosis. Depending on the strictness of the standards of diagnosis employed, the likelihood that a sibling of a child already diagnosed will also show autism are small to modest. However, it is not surprising that the correlation among identical twins appears to be very high.
Brain and physiological differences: It is now known—in no small part due to the efforts of the Autism Tissue Project—that brain structures of IWAs tend to differ in several ways from those of their neurotypical peers in several different ways. These differences are very complicated, however, and it is important to avoid making sweeping generalizations.
A developing fetus will develop more neural connections than can survive while the fetus matures and the child is born. All individuals will tend to lose some of these connections. It is believed that IWAs may lose different connections than those lost by most people. This may account for special abilities in some areas that are better supported and impairments in others where neural connections have been sacrificed.
The structure of brain connections also tend to differ in IWAs. In some parts of the brain (but only some), IWAs will tend to have a greater proportion of “white,” as opposed to “gray,” matter. The white matter generally connects neurons. This may explain, again, certain abilities—especially creative ones—shown by some IWAs. Unfortunately, however, the neural pathways, or dendrites, in the brains of IWAs tend to have a considerably less rich “root” structure, reducing other types of connections. One might speculate, then, that this may account in part for difficulties that IWAs often have in generalizing.
The human brain tends to assign certain tasks to certain specialized parts of the brain (although parts of the brain can be “reassigned” after an accident, for example). This is much like the division of labor we see among people. Many people can perform car repairs, but trained mechanics will usually do a better, more efficient, and faster job. In IWAs, much of the brain area specialization does not seem to occur. For example, most people rely strongly on a brain area called the amygdala to recognize faces. Brain scans of IWAs have shown that facial recognition tends to be much more dispersed. This has several consequences in that recognizing a face will (1) take longer, (2) be more exhausting, (3) be somewhat less reliable.
Comorbidity. The medical profession tends to use this rather frightening term to describe how certain other conditions tend to show up disproportionately frequently in IWAs. Figure 1 illustrates certain conditions frequently observed along with autism.
Depression frequently co-occurs in autism. This may be because depression and autism may be each caused in part by similar biochemical imbalances in the brain. Another reality is that an unpredictable and unfriendly world can be very depressing to someone who dislikes surprises and changes in routines while taking little if any joy in social activities that can serve as emotional “boosts” for others.
Obsessions and compulsions are frequently observed in autism and are, in fact, reflected in the criteria for diagnosis. Other people not diagnosed with autism can suffer from Obsessive-Compulsive Disorder (OCD). Interestingly, the medications used to treat depression of OCD overlap a great deal.
Medication. There are currently no medications on the market in the U.S. explicitly approved to treat autism as a whole. Instead, a patchwork of medications are used to treat various symptoms individually. The medications that may benefit each individual appear to vary significantly, and the values that one holds with respect to the use of medications may influence one’s decisions in large part. Several types of medications are frequently used, often in combination:
§ Stimulants: Because IWAs often have problems with attention, medications developed for treating Attention Deficit/Hyperactivity Disorder (ADHD) are sometimes used. These can help not only to improve concentration, but also to reduce hyperactivity. Two types of ADHD medications used are the stimulants and the amphetamines. Ritalin, whose generic name is methylphenidate, is perhaps the most well known ADHD medication and is a stimulant. One serious problem with Ritalin is that it lasts only for a short period of time, with the patient experiencing a “downturn” as the medication wears off. More recently, Concerta has been put on the market. Concerta tablets are more slowly released into the body, lasting for six to twelve hours. For children, a single dosage administered at home in the morning avoids stigmatizing trips to the school nurse, and wear-off lows are minimized. Amphetamines such as Adderal and Dexedrine serve much the same function. Stimulants and amphetamines are very controversial for use within ADHD, and medical researchers presenting at autism conferences have expressed rather divided opinions on their effectiveness for use within autism (especially for children).
§ Antidepressives. Many individuals who are eventually diagnosed with autism are often diagnosed with depression earlier. There are several kinds of antidepressive medications on the market. Most work, in some way, on one or more of the following neurotransmitters: serotonin, norepinephrine, and dopamine. Common medications are Prozac, Wellbutrin, Zoloft, and Paxil. In the old days, the so-called “tricyclic” antidepressants had serious side effects such as dry mouth, but side effects of modern medications tend to be much milder.
§ Anti-OCD medications. As discussed above, these overlap to some extent with anti-depressives.
§ Neuroleptics. These medications, also known as anti-psychotics, are normally used to treat conditions such as schizophrenia. Often, these carry serious side effects, including large weight gain and the risk of body tremors.
Numerous other pharmaceutical approaches are being investigated. Secretin, for example, may turn out to hold promise for some subsegments of IWAs. As with many other treatments, there are serious questions of placebo effects.
§ Language: IWAs often show certain language differences. “Echolalia,” or the tendency to repeat phrases over and over, is common. Some high functioning individuals may develop a surprisingly formal and seemingly mature speech pattern. And some can write with unusual beauty. Sometimes, IWAs may be very inventive in coining new words—e.g., Tony Attwood relates the example of “tidying down” a room. Usually, however, there is a tendency toward very literal and concrete expressions and interpretation.
§ Abstraction. It has often been remarked that IWAs seem to have difficulty with abstraction. Often, communication is interpreted very literally, and there is difficulty in generalizing from one situation to another. Yet, IWAs often have very abstract interests. The concept of the “literal detour” (Perner, 2001) addresses this paradox. It is suggested that the IWA is more likely to immediately visualize the literal metaphor while others may go directly to a socially defined meaning. In order for the IWA to “get” the non-literal meaning, it is then necessary that the metaphor is recognized as one too absurd to be intended. This process often takes time, however.
§ Inferences: IWAs often have difficulty making inferences that come naturally to others. Most people, for example, will infer that someone who is smiling may be joking, but IWAs may miss out on this cue. Thus, context may be ignored.
Challenges and Compensatory Strategies. A five function model of performance suggests how IWAs perform on tasks overall. One can understand areas of strength and weakness by considering the relationships between the instinctive, intuitive, executive, intellectual, and compensatory functions.
Theory of Mind and Empathy. Work pioneered by Simon Baron-Cohen has suggested that individuals on the autistic spectrum often have difficulty in understanding that others have different thoughts from their own. Similarly, it has traditionally been believed that IWAs tend to lack empathy. While it is true that IWAs often have difficulty intuiting exactly what other people are feeling, it is a mistake to believe that they are indifferent. Many IWAs have been found to have a strong sense of social justice and a great deal of compassion for others.
Lifespan Issues. The term “pervasive developmental disorder” implies that personal growth may be generally impaired. Frequently, maturation is delayed or fails to occur. One suggested rule of thumb is that an individual with Asperger’s Syndrome is likely to have matured in some areas at about two thirds the rate of a similarly aged neurotypical peer.
It is important to note that rather fundamental changes in personality may occur as the individual adjusts over life. For example, someone who holds very rigid views of truth and reality may be quite confrontational in early life. Later on, however, he or she may realize that it really is not worthwhile to bother with correcting unappreciative others, and may thus become quite non-confrontational. Both extremes, then, are quite consistent with characteristics of autism.
While the IWA may receive a number of services while young, such services may not be as readily available later in life.
Frith, Uta (1991). “Asperger and His Syndrome.” In U. Frith (ed.), Autism and Asperger’s Syndrome. Cambridge: Cambridge University Press.
Perner, Lars (2001). “Literal Detours: Propositions On Abstraction In High Functioning Individuals With Autism.” Paper presented at the annual meeting of the American Psychological Association, San Francisco, CA, August 24-28, 2001. http://www.highfunctioningautism.com/ .