What It Means to Have Autism

In the material that follows, we'll distinguish between typical traits of children with autism and typical traits of children with PDD when possible, but the reader should bear in mind that everything said about autism can sometimes be true about PDD--but the degree of severity, or overall number of symptoms experienced, varies.

The DSM-IV Criteria for Autistic Disorder and PDD,NOS

At present, when autism is diagnosed in the United States, the clinician is probably using a diagnostic standard called the DSM-IV, which is an acronym for the Diagnostic and Statistical Manual of Mental Disorders of the American Psychiatric Association, Fourth Edition, which was published in 1994. Use of a standard diagnostic definition is designed to ensure that there will be agreement among doctors in different places as to what is being called autism, and where the line is supposed to be drawn between autism and PDD. But there are differences in how the DSM-IV criteria for autism are actually used. For example, doctors with different degrees of specialization in autism tend to use the label differently. This is because many adjectives used to describe symptoms of autism like "diminished" or "abnormal" or "impaired" or "atypical" may be interpreted to indicate different thresholds of severity by different professionals. It would be ideal if doctors had some sort of videotaped glossary of each symptom of autism that showed several examples of children doing things that were intended to be interpreted as meeting the criteria for various symptoms of autism, so that everyone could use the same yardstick to measure when "lack of awareness of others" really was "marked," or "ability to make peer friendships" was really "impaired." That isn't the case. It's one reason why the same symptoms can be differently interpreted at different diagnostic centers.

The twelve diagnostic criteria for DSM-IV Autistic Disorder are grouped into three areas--social development, communication, and activities and interests. Within each area are four specific criteria, each representing a different area of symptoms. Generally, the first criterion in each of the three areas is the one that can be detected at the earliest age, and the latter ones in each area are the ones that become apparent later on in development. In addition, each of the criteria should be evaluated according to the child's level of mental development so that developmental delay is not confused with autistic symptoms. The need to evaluate possible signs of autism according to the child's level of mental development is one reason why it is important to have IQ (intelligence) or adaptive behavior testing done as part of a diagnostic assessment. A child's developmental level can be estimated by an IQ test or a test of adaptive behavior, which is a way of measuring how of the child uses his intelligence to adapt to the challenges of everyday life.

The Concept of Nonverbal Intelligence. Some of the most clinically useful research on diagnosing autism suggests that each diagnostic criterion be rated according to the child's nonverbal level of mental development. This is a very helpful way to think about the symptoms of autism because impaired verbal ability is, itself, a part of many signs of autism. By judging signs of autism in accordance with a child's nonverbal ability, there is a further check that other types of language delay are not confused with autistic symptoms. Nonverbal intellectual functioning includes nonlanguage abilities, which for young children can be assessed by how well they can put together puzzles, sort things, and copy actions they've seen. This can be contrasted with verbal intelligence that involves language use and understanding – which is always affected in certain ways in autistic children. Therefore, a measure of mental development for the purposes of assessing autistic symptoms is estimated through the child's functioning in areas not as directly affected by the presence of the symptoms of autism.

Using nonverbal intelligence as a way of estimating an autistic child's general level of mental development is not a perfect indicator, but it does provide a basis for separating many of the effects of mental retardation from the autism itself. Nevertheless, the majority of autistic children have some degree of mental retardation along with their autism, so it is important to find a way to measure it separately from the symptoms of autism. This is because delays in development due to autism or PDD and delays in development due to mental retardation are not always treated in the same way. By using the child's level of nonverbal IQ (nonverbal mental age) as a baseline, we are essentially asking "How does this child's behavior in each autistic symptom area compare to what a child should typically be able to do at this mental age?" Once there is a general fix on the child's nonverbal mental age (which a professional obtains through a combination of intelligence testing, observations of the child, and parent interviewing), it is possible to assess the child for the presence of autistic symptoms. (In Chapter 5 we will look at diagnostic procedures in more detail.)

Autistic Disorder. To be diagnosed as having autistic disorder, using the DSM-IV criteria, a person must have positive signs on six out of the twelve criteria. At least two of the criteria met must reflect difficulties in social development; two criteria must be met in the area of communication; and at least two criteria in the area of atypical activities and interests must also be met.

Pervasive Developmental Disorder, Not Otherwise Specified (NOS). If the child has a less severe form of the behavior described in a criterion, that may contribute to a diagnosis of PDD, NOS. If no criteria is met in the category of atypical activities and interest (part C in Table 1), but the child does show a variety of signs in the categories of social and communicative development, the diagnosis of PDD,NOS is also used. Sometimes, some doctors will use PDD, NOS provisionally when the child is so young that many of the criteria are felt to be too difficult to see. This is problematic, because other clinicians who are very experienced with young autistic children can tell fairly accurately from the early profile of symptoms that are met whether the child has autism or PDD,NOS. This is because they understand what the earliest forms of autistic symptoms are. Using such early developmental guidelines, a clinician who is experienced with young autistic children can often tell if a child is autistic by a child's second birthday and sometimes sooner. As we'll discuss later, it's important to get a diagnosis as early as possible. As specific symptoms are discussed, we'll cover what the earliest forms look like.

Table 1 DSM-IV Criteria for Autistic Disorder and Pervasive Developmental Disorder, Not Otherwise Specified (PDD, NOS)

To be diagnosed with autistic disorder at least one sign (each) from parts A, B, and C must be present, plus at least six overall. Those meeting fewer criteria are diagnosable as PDD,NOS.

 

A. Qualitative impairments in reciprocal social interaction:

  1. Marked impairment in the use of multiple nonverbal behaviors such as eye-to-eye gaze, facial expression, body posture, and gestures to regulate social interaction.

  2. Failure to develop peer relationships appropriate to developmental level.

  3. Lack of spontaneous seeking to share enjoyment, interests, or achievements with others.

  4. Lack of socioemotional reciprocity.

B. Qualitative impairments in communication:

  1. A delay in, or total lack of, the development of spoken language (not accompanied by an attempt to compensate through alternative modes of communication such as gesture or mime).

  2. Marked impairment in the ability to initiate or sustain a conversation with others despite adequate speech.

  3. Stereotyped and repetitive use of language or idiosyncratic language.

  4. Lack of varied spontaneous make-believe play or social imitative play appropriate to developmental level.

C. Restricted, repetitive, and stereotyped patterns of behavior, interests, or activity:

  1. Encompassing preoccupation with one or more stereotyped and restricted patterns of interest, abnormal either in intensity or focus.

  2. An apparently compulsive adherence to specific nonfunctional routines or rituals.

  3. Stereotyped and repetitive motor mannerisms (e.g., hand or finger flapping, or twisting, or complex whole body movements).

  4. Persistent preoccupation with parts of objects.

Abnormal or impaired development prior to age three manifested by delays or abnormal functioning in at least one of the following areas: (1) social interaction, (2) language as used in social communication, or (3) symbolic or imaginative play.

Source: The Diagnostic and Statistical Manual, 4th Edition, American Psychiatric Association, 1994.

One of the problems in using the diagnosis of PDD,NOS is that the lower limit is not clearly specified. It is clear that to receive a diagnosis of PDD,NOS a child should have difficulties in some of the areas listed in the social (part A) and the communicative (part B) categories (see Table 1). However, some clinicians might give a diagnosis of PDD,NOS to a child who meets as few as two criteria for PDD, NOS (that is, one from part A and one from part B). Although this is not strictly incorrect, clinically it matters a great deal which criteria the child meets, as some of the problems that PDD children have are also common in children with related problems like developmental language disorders. That's one reason why a diagnosis of PDD,NOS needs to be made by someone experienced with PDD children rather than by a clinician who is more experienced with other childhood difficulties and is relying strongly on the DSM manual for guidance.

ICD-10 versus DSM-IV Pervasive Developmental Disorders

While the American Psychiatric Association maintains its own standards, the rest of the world maintains theirs. ICD-10, International Classification of Disease, Tenth Edition is another diagnostic manual of medical terms. Its development and ongoing revision process is sponsored by the World Health Organization, which is based in Geneva, Switzerland. In 1994, 1CD-10 be-came the newest international standard, and with it, new criteria for diagnosing autism appeared. There are close parallels between DSM-IV and ICD-10 criteria for autism, and a large international study of almost 1,000 children was carried out to ensure that the two sets of diagnostic criteria would essentially identify the same individuals. Therefore, it is fairly unusual to find a child who is diagnosed autistic by DSM-IV criteria and not by lCD-10 criteria, and vice versa. When a diagnosis of autism or PDD is made, the doctor making the diagnosis can tell you which standard is being used (See Table 2).

Table 2 ICD-10 Criteria for Autistic Disorder

  1. Presence of abnormal or impaired development in at least one of the following areas from before the age of three years (usually there is no prior period of unequivocally normal development, but when present, the period of normality does not extend beyond three years):

    1. Receptive or expressive language as used in communication.

    2. The development of selective social attachments and/or of reciprocal interaction.

    3. Functional and/or symbolic play.

  1. Qualitative impairments in reciprocal social interaction:

    1. Failure adequately to use eye-to-eye gaze, facial expression, body posture and gesture to regulate social interaction.

    2. Failure to develop (in a manner appropriate to mental age and despite ample opportunity) peer relationships that involve mutual sharing of interests, activities, and emotions.

    3. Rarely seeking or using other people for comfort and affection at times of stress or distress and/or offering comfort and affection to others when they are showing distress or unhappiness.

    4. Lack of shared enjoyment in terms of vicarious pleasure in other people's happiness and/or a spontaneous seeking to share their own enjoyment through joint involvement with others.

    5. A lack of social-emotional reciprocity as shown by an impaired or deviant response to other people's emotions; and/or lack of modulation of behavior according to social context, and/or a weak integration of social, emotional, and communicative behaviors.

  1. Qualitative impairments in communication:

    1. A delay in, or total lack of, spoken language that is not accompanied by an attempt to compensate through the use of gesture or mime as alternate modes of communication (often preceded by a lack of communicative babbling).

    2. Relative failure to initiate or sustain conversational interchange (at whatever level of language skills are present) in which there is no reciprocal to and from responsiveness to the communications of the other person.

    3. Stereotyped and repetitive use of language and/or idiosyncratic use of words or phrases.

    4. Abnormalities in pitch, stress, rate, rhythm, and intonation of speech.

    5. A lack of varied spontaneous make-believe play or (when young) in social imitative play.

  1. Restricted, repetitive, and stereotyped patterns of behavior, interests, and activities:

    1. An encompassing preoccupation with stereotyped and restricted patterns of interests.

    2. Specific attachments to unusual objects.

    3. Apparently compulsive adherence to specific, nonfunctional routines or rituals.

    4. Stereotyped and repetitive motor mannerisms that involve either hand/finger flapping or twisting, or complex whole body movements.

    5. Preoccupations with part-objects or nonfunctional elements of play material (such as their odor, the feel of their surface, or the noise/vibration they generate).

    6. Distress over small, nonfunctional details of the environment.

  1. The clinical picture is not attributable to other varieties of pervasive developmental disorder (Asperger's syndrome, Rett's syndrome, Childhood Disintegrative Disorder) nor to a specific developmental disorder of receptive language with specific socioemotional problems, reactive attachment disorder, mental retardation with some associated emotional/behavioral disorder, nor schizophrenia of unusually early onset.

Source: International Classification of Diseases, Tenth Edition, World Health Organization, 1994.