Mental Health Aspects of Autism and Asperger Syndrome

Mohammad Ghaziuddin

• Publisher: Jessica Kingsley Publishers
• Year: 2005
• Print ISBN: 9781843107330
• eBook ISBN: 9781846421051
• Topic: Education
• Subtopic: Inclusive Education

The first book to address the increasingly urgent need for information about psychiatric problems in people with autism spectrum disorders (ASDs), Mental Health Aspects of Autism and Asperger Syndrome systematically explains the emotional and psychological difficulties that are often encountered with ASDs. The author, an experienced psychiatrist specializing in autism, describes each of the conditions that are commonly seen in autistic children and adults, including schizophrenia, depression, anxiety, and tic disorders, and gives sound guidance on their early detection and treatment. Easy to use and authoritative, this book is an essential tool for use by both family and professionals.

CHAPTER 1

Autism and Pervasive Developmental Disorders: An Overview

Introduction

Autism is a severe, handicapping disorder of early childhood characterized by a distinct pattern of social deficits, communication impairment, and rigid ritualistic interests. These symptoms, however, are not specific to the disorder. They occur not only in other psychiatric conditions but also in the normal population. Several people in the community show autistic traits, but they do not meet the diagnostic criteria of autism because either their symptoms are not severe enough to cause impairment or they do not cluster together. The key to the diagnosis, therefore, lies in the clustering together of the three different types of symptoms – reciprocal social problems, communication deficits, and restricted interests – all of which start early in life, usually before the age of 3 years.

Historical background

Leo Kanner (1943), a child psychiatrist at Johns Hopkins University in Baltimore, USA, first described this condition based on his observations in eleven children. These children, he believed, were born without the usual ability to form relationships with others. They all had problems in relating, difficulties in communicating, and a tendency to perform routines and rituals. Kanner believed that these problems stemmed from two basic deficits: aloofness and a desire for sameness. His description of the clinical features of autism has stood the test of time. Widely regarded as the most clearly defined psychiatric disorder of childhood, autism occurs in all cultures and countries.

Classification

Although autism was described in the 1940s, it was introduced as a formal diagnostic category much later. Over the years, its diagnostic criteria have gone through several changes and revisions. Currently, it is classified as a pervasive developmental disorder (PDD), although the term ‘autism spectrum disorder’ is being increasingly used. These disorders are characterized by a distinct pattern of deficits involving multiple areas of functioning, namely, socialization, communication, and imagination. Some authorities have questioned the rationale of labeling these conditions ‘pervasive’ because there are other conditions, such as mental retardation, which may also be placed under this category. However, at this time, the official position of both the American DSM (APA, 1994) and the WHO’s ICD (1993) is to regard autism as the main category within the group of PDDs. Before the early 1990s, there were only two main categories in the PDDs: autistic disorder and Pervasive Developmental Disorder Not Otherwise Specified (PDDNOS). Patients who met the required criteria for autism were called autistic, and those who fell short of meeting the full criteria were grouped together under the residual category of PDDNOS. Later, three new disorders were split off from PDDNOS, namely, Asperger syndrome, Rett’s syndrome, and disintegrative disorder. These disorders are discussed in Chapters 2 and 3.

Prevalence

Recent reports have suggested a marked increase in the prevalence of autism (see Chakrabarti and Fombonne, 2001). While it is not yet clear as to why this is the case, several theories have been proposed. These range from an increasing awareness of the diagnosis to a broadening of the diagnostic criteria. While clinical evidence suggests that the increase is widespread, data are limited only to western countries. A recent study in California found a threefold increase in the number of autistic cases from 1987 to 1998 that did not seem to be the result of changes in diagnosis or of such external factors as immunization and birth injuries (Blakeslee, 2002). Traditionally, the estimate of autism is given as four or five per 10,000 children. However, several reports now suggest estimates as high as one per 500 children or even more, when conditions such as Asperger syndrome and PDDNOS are included in the broad definition of autism. For example, a British survey gave a prevalence rate of 26 per 10,000 in children aged between 5 and 15 years (Fombonne et al., 2003).

Causes of autism

There is no single cause of autism. It is described as a multifactorial disorder in which both genetic and environmental factors play a role. While the extent to which each of these factors operates in any single case depends on the individual case, there is a consensus that autism is a neuropsychiatric disorder that is caused by some as yet undefined biological factor. This factor, perhaps in combination with a pre-existing genetic vulnerability, results in the clinical syndrome of autism.

Genetic factors

The association of genetic factors in the etiology of autism is well established. Several family and twin studies have shown that the disorder is strongly influenced by genetic factors. The chances of having a child with autism are significantly increased if the couple already has one such child. In line with research done in other branches of medicine, it is now generally believed that what is transmitted is not autism itself, but a tendency to it.

People with autism not only have an increased family history of autism, but also of autistic traits. These traits are collectively referred to as the ‘broader autistic phenotype’ (BAP). Also sometimes referred to as the lesser variant of autism, this concept describes a condition in which a person shows many of the features of autism without meeting its full diagnosis. Thus, there may be an excess of such personality traits as rigidity and awkwardness (Bolton et al., 1994). That the parents of autistic children show an excess of such characteristics was known even at the time of Kanner (1943). However, at that time it was widely believed that the presence of those traits supported a psychogenic, rather than a biologic, origin of the disorder.

In addition to the increase of autism and autistic-like traits in the family members, there is also an increase of a variety of psychiatric disorders. Thus, parents of autistic children show an increase in depression and anxiety disorders. Compared to a group of parents with Down syndrome, parents of autistic children show an increased prevalence of psychiatric disorders, thus underscoring the fact that these disorders do not result from the burden of care inherent in raising a handicapped child (Piven et al., 1991). Sometimes, the presence of psychiatric disorders, such as depression, in the parents of autistic children is correlated with the prevalence of similar disorders in the autistic children themselves (Ghaziuddin and Greden 1998). The last decade has witnessed an enormous surge of knowledge in molecular genetics. Findings at this time suggest that autism probably results from at least three to twenty genes and that there is no single gene for autism. Promising as these studies are, they are preliminary in nature, and need to be replicated.

Environmental factors

While autism is characterized by a strong genetic component, the dramatic increase in recent years, if accurate, raises the possibility that environmental factors may also be at work. Some of the environmental agents that have been implicated are briefly discussed below.

•Viruses: Some researchers believe that viruses can cause autism. While several viral disorders have been associated with autism, it is unclear to what extent they directly result in the symptoms of autism. For example, herpes virus attacks the brain directly. Case reports have described the emergence of autistic symptoms after herpes encephalitis both in children (Ghaziuddin, Al-Khouri and Ghaziuddin, 2002) and in adults (Gillberg, 1991). In addition to herpes, other viruses that have been implicated in the etiology of autism include the measles virus and the cytomegalovirus.

•Valproate and thalidomide: Reports have described the association of autism with fetal valproate syndrome (Williams et al., 2001). The exposure occurs when the mother is exposed to valproate during the first trimester of pregnancy. Similar associations have also been proposed between autism and thalidomide. Of a population of 100 Swedish thalidomide embryopathy cases, at least four met the criteria for autism. The authors proposed that thalidomide embryopathy of the kind encountered in these cases affects fetal development early in pregnancy, probably on days 20 to 24 after conception (Stromland et al., 1994).

•Mercury: Hazards of mercury have been linked to a variety of behavioral and cognitive problems in children. There are some reports of its association with lower IQ, Attention Deficit Hyperactivity Disorder (ADHD), and autism. The mercury-containing preservative thimerosal, contained in some vaccines, has been linked to autism. However, a recent study that examined infants who received vaccines containing thimerosal found that the levels of mercury in their blood were within safety limits (Pichichero et al., 2002).

Neurobiology of autism

•Neurochemistry: About one third of patients with autism show increased levels of the neurotransmitter serotonin in the blood. However, many mentally retarded persons also show this abnormality. It is, therefore, unclear to what extent serotonin dysfunction is responsible for all the symptoms of autism.

•Post-mortem studies: Because of practical reasons, few post-mortem studies have been done. Although there are no gross alterations in the appearance of the brain, subtle changes have been seen in the way cells are packed in some regions (Bauman, 1991). Abnormalities in the temporal lobes and the cerebellum have also been described.

•Neuroimaging studies: A wide variety of abnormalities has been shown in persons with autism on computerized tomography (CT) scan and magnetic resonance imaging (MRI) studies. Some of these include enlargement of the cerebral ventricles, and abnormalities of the cerebral cortex and the basal ganglia (Piven et al., 1990). However, these findings are not specific to autism, and may reflect the consequences of the disorder, rather than its cause.

Neuropsychology of autism

Several neuropsychological abnormalities characterize autism. Intellectual deficits are common, with at least half of all people with autism showing an IQ below 70. However, if milder variants of autism are included, perhaps fewer autistic patients have mental retardation than is generally believed. Most autistic patients show problems with abstraction, and on IQ tests most have a better ability to focus on parts of a puzzle rather than the whole. Likewise, verbal IQ scores are often suppressed in comparison with performance IQ scores. In addition, there are abnormalities in the ability to read other peoples’ emotions and feelings. Often described as Theory of Mind (TOM) deficits, these explain why autistic persons find it difficult to make judgments about others (Baron-Cohen, 1989). However, TOM deficits do not explain other symptoms of autism, such as ritualistic behaviors. Other theories, such as the Central Coherence Theory¹ (Frith, 1996), attempt to explain how intense focus on certain areas can interfere with social and communication functioning. Deficits in executive functioning also occur which interfere with the individual’s ability to plan and execute actions satisfactorily. A selective impairment of the ability to recognize human faces has also been described (Schultz et al., 2000).

Clinical features

Behavioral abnormalities

Although the boundaries of autism remain fuzzy, there is a general consensus that all autistic people share certain qualities that set them apart from others: they are rigid, mechanical, and emotionally distant.

SOCIAL INTERACTIONS

People with autism have reciprocal social deficits. They lack the ability to interact in a to-and-fro manner with others. Their quality of interactions lacks flexibility and spontaneity. Although autistic persons are able to form relationships, it is the way those relationships are formed that is distinctly different from normal human relationships. At times, these deficits are so mild, especially in adults with autism, and in those who do not suffer from mental retardation, that they may be missed at first glance.

COMMUNICATION

Perhaps the most common symptom that arouses parental concern is the child’s inability to communicate. According to some estimates, at least a quarter of all children with autism fail to develop meaningful speech. Many a time, the autistic child will communicate his needs by leading the parent by the arm, and using the arm as if it were an extension of his (the child’s) body, for example, using the parents arm to open a door or get an object. Speech is often delayed, and those who eventually speak, show a variety of abnormalities both in the form as well as in the content of speech. Several types of speech abnormalities may occur, including a tendency to repeat the speech of others, and sometimes to repeat phrases and sentences heard in the recent past. Problems with eye contact, facial expression, and other aspects of nonverbal communication are often present. The tone and pitch of the voice may also be different. Sometimes the child may speak in a loud voice; at other times, the voice may have a sing-song quality.

RESTRICTED INTERESTS

Restricted and ritualistic interests form the third main clinical feature of autism. These depend on the level of intelligence (Bartak and Rutter, 1976). ...

Table of contents

• Cover Page
• Title Page
• Copyright
• Contents
• List of Figures, Tables and Boxes
• Preface
• Chapter 1. Autism and Pervasive Developmental Disorders: An Overview
• Chapter 2. What is Asperger Syndrome?
• Chapter 3. Other Pervasive Developmental Disorders
• Chapter 4. Medical Conditions in Autism
• Chapter 5. Psychiatric Comorbidity: An Introduction
• Chapter 6. Attention Deficit Hyperactivity Disorder
• Chapter 7. Depression and Other Mood Disorders
• Chapter 8. Anxiety Disorders in Autism and Asperger Syndrome
• Chapter 9. Schizophrenia and Other Psychotic Disorders
• Chapter 10. Autism, Tic Disorders, and Tourette Syndrome
• Chapter 11. Other Psychiatric Disorders
• Chapter 12. Violence in Autism and Asperger Syndrome
• Chapter 13. Psychiatric Comorbidity of Autism Spectrum Disorders: The Task Ahead
• Subject Index
• Author Index