Pervasive Developmental Disorders Essay Example for Free

Pervasive Developmental Disorders Essay The pervasive developmental disorders (PDDs) represent a spectrum of difficulties in socialization, communication, and behavior. Autism is the best recognized and most frequently occurring form of a group of the PDDs. Because most of the research in areas related to communication has been done on autism, we will focus here on this particular PDD. However, we should be aware that autism is probably not the most common disorder on this spectrum. Other types of PDDs include Retts Disorder, Childhood Disintegrative Disorder, Aspergers Disorder, and Pervasive Developmental Disorder Not Otherwise Specified, or PDDNOS (Twachtman-Cullen 1998). This work will also discuss the distinctive features of Aspergers syndrome, which is believed to be genetically related to autism. Much of what can be said about certain features of autism and PDDNOS applies to other forms of non-autistic PDD. The goal of this research is to provide a framework for understanding cognitive development in children with PDDs. The study will cover criteria for early PDDs diagnosis. The best-known type of PDDs is autistic disorder (variously called autism or infantile autism). The symptoms of autistic disorder typically increase gradually through the childs second year, reach a peak between 2 and 4 years of age, and then show some improvement. Young children with greater cognitive ability who receive very early intensive intervention may show dramatic improvement at this age, whereas those who are more impaired will make more modest changes. Persons with autistic disorder exhibit major deficits in their ability to relate to others. The child with autistic disorder often appears content to dwell in a separate world, showing little empathic interest in parents or siblings. Unlike the normally developing baby, the child with autistic disorder may not raise his arms to be picked up or may stiffen in protest when his parents try to cuddle him. The childrens lack of social interest may make some of these babies seem like â€Å"easy babies† because they do not seek parental attention, and appear content to remain in their cribs, watching a mobile or staring at their hands. As they get older, such lack of demandingness is recognized for the relative indifference it actually reflects. The child with autistic disorder may not seek others for comfort when she is hurt or upset, finding little consolation in the gentle words and hugs that are so important to other children. Not only do the children not ask for comfort, they typically are quite indifferent to other peoples distress and do not seem to share their joy. A siblings tears or a parents happiness may elicit no response from the child with autistic disorder. Children with autistic disorder show little interest in the domestic imitation that most children enjoy. For example, unlike the normally developing child, the child with autistic disorder usually does not use his miniature mower to cut the grass like mommy or pretend to shave while he watches daddy. This lack of interest in imitation interferes with one of the primary channels for learning by young children: their ability to model adult behaviors and master them through role play. Social play is one of the primary activities of childhood. A few simple toys can create the backdrop for long hours of companionship. The child with autistic disorder does not know how to join this kind of play, sometimes completely ignoring other children, or perhaps standing on the sidelines, not comprehending how to become part of the group. Not surprisingly, given the range of social deficits they exhibit, children with autistic disorder are very impaired in their ability to make childhood friends. Within the communication domain, impairments are present in a number of linguistic and nonverbal areas, the most fundamental of which are pragmatics and semantics (i. . , the social usage and explicit or implicit meaning of language and gestures). Although linguistic capability varies greatly across the spectrum (from a total absence of speech to highly sophisticated and erudite language), significant impairments in pragmatics and semantics are universal among individuals with PDDs. They communicate primarily to express needs, desires, and preferences, rather than to convey sincere interest in others, or to share exp eriences, excitement, and feelings. Even among those possessing highly sophisticated and complex language, compliments, words of empathy, and expressions of joy in the good fortune of others are very rare. There is little reciprocity, mutuality, or shared purpose in discussions. In addition, speech and gestural forms of communication are poorly integrated, often resulting in awkward and uncomfortable social interactions. Implicit, subtle, and indirect communications are neither used nor perceived. Expressive communication tends to be explicit, direct, and concrete. During discussions, persons with autism often fail to prepare their speaking partners for conversational transitions, new topics, or personal associations. This can result in digressive, circumstantial, and tangential comments and discussions. It would appear as though persons with autism assume that others are implicitly aware of their experiences, viewpoints, attitudes, and thoughts. The fashion in which these deficits are manifest is influenced by age, overall cognitive level, temperament, and the presence of sensory or physical limitations. In toddlers, for example, impaired pragmatics may be manifested by significant limitations in reciprocal eye contact, responsive smiling, joint attention (mutual sharing of interests and excitement), and social imitative play. In addition, socially directed facial expressions, instrumental and emphatic gestures, and modulation of speech prosody (intonation, cadence, and rate) are rarely used to complement speech, communicate feelings and attitudes, or moderate social discourse. Among preschool children, impairments in symbolic functioning (e. g. , language) are accompanied by serious limitations in pretense (e. g. ymbolic, imaginative, creative, and interactive play). Pragmatic impairments among adolescents with Asperger’s syndrome may be manifested by one-sided, pedantic discussions, with no attempt to involve speaking partners by acknowledging and integrating their experiences, ideas, and viewpoints into conversations. Sincere attempts by others to engage in reciprocal conversations may be met with a lack of acknowledgment, annoyance, and disinterest. Comments or questions that are â€Å"snuck in† by the listener may be experienced as rude interruptions, prompting the directive, â€Å"Wait! Im not done talking yet† (Bernabei, Camaioni Levi 1998). The result is a monologue or lecture that often includes abrupt changes of topic and the introduction of unexplained personal associations. This lack of conversational reciprocity suggests that persons with AS and high-functioning autism inherently assume that the listener is implicitly aware of their own experiences, viewpoints, and intent. Because the relaying of factual and concrete information is the primary goal of â€Å"social† dialog among those with ASD, the communication of subtle attitudes, viewpoints, and emotions (particularly secondary emotions, such as embarrassment, guilt, and envy) are largely irrelevant and superfluous. Therefore, emphatic gestures, informative facial expressions, and vocal modulation lack essential meaning for them. The result is that persons with autism generally disregard nonverbal cues and fail to incorporate them into their own discussions. Because this component of social communication often conveys essential information regarding feelings, attitudes, and opinions, an inability to identify, interpret, and produce nonverbal cues can have a highly detrimental effect on social interactions and relationships. Given these impairments, it is not surprising that verbal and nonverbal aspects of communication are poorly integrated, and that subtlety and nuance are rarely conveyed. Figurative and inferential language is another area of communication that is impaired in autism, largely due to a combination of deficits in abstract and conceptual thought, social reciprocity, and appreciation of the subtleties of social communication. Persons with ASD are highly literal and concrete in their language and thought processing, typically failing to understand metaphor, irony, sarcasm, and facetiousness. As a result, comments are often misinterpreted and discussions misunderstood. In addition, in an effort to remain true to the facts, comments and questions are often presented in an overly direct, straightforward, and â€Å"brutally honest† manner, lacking appropriate tact and sensitivity (Szatmari, Jones, Fisman, Tuff, Bartolucci, Mahoney 1995). This can cause embarrassment and distress for the listener and confusion for the speaker with AS. Both may become angry and resentful; the listener, because of emotional distress and perceived mistreatment; the speaker, because of the seemingly unjustifiable overreaction and a negative attitude displayed by the listener. From the perspective of the person with AS, the listener responded in a rude and ungrateful manner to comments that were intended to be informative, useful, and corrective. The emotional distress, embarrassment, and attack on self-esteem experienced by the listener are relatively foreign to the individual with autism. Interestingly, principles, rules, and codes of behavior can be interpreted in a highly concrete and rigid manner. This can result in insensitive and hurtful comments and behavior, because exceptions to the rule, adjustments to unexpected social contingencies, and appreciation for the spirit (not simply the letter) of the law are relatively foreign to those with autism. There is little awareness that rigid adherence to unavoidably flawed rules can result in a situation that is antithetical to the underlying intent of the rule itself. One of the dinning features of autism and Asperger’s syndrome is that of rigidity and inflexibility in response to minor change and transition in the environment and daily routines. This insistence on sameness and invariance can be highly impairing, because the precipitants of these reactions often are of little social significance and do not disturb the smooth functioning of the social world. It is as though persons with autism depend on these inanimate markers of space and time because the social priorities that typically direct schedules and routines have little meaning and significance for them. Aspergers Syndrome has been associated with cognitive strength since Hans Asperger first described the disorder in the 1940s. When he wrote of children who sounded like â€Å"little professors,† Dr. Asperger (1944/1991) was describing not only their pedantic tone but also their cognitive abilities. The assumption of adequate cognitive skill was reiterated when the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) stated that individuals with Aspergers Syndrome show â€Å"no clinically significant delay in cognitive development† (Willey 2001). Aspergers syndrome (AS) was added as a new â€Å"official† diagnosis when DSMIV and ICD-10 were published. In the past, children with AS were sometimes referred to as having schizoid personality, or schizotypal personality, and PDD, NOS. It is now recognized as distinct from autism. AS differs from autism in a number of key ways: first, children with AS may not be detected as early because they may have no delays in language, or only mild delays. In fact, it is usually not until parents notice that their childs use of language is unusual, or their childs play is also unusual, that concern sets in. Unlike autism, where the vast majority of children also experience some degree of mental retardation, children (and adults) with AS are rarely mentally retarded although many have low-average intelligence. Children with AS are sometimes described as â€Å"active, but odd† not avoiding others the way autistic children often do, but relating in a more narrow way, usually centering activity around their own needs and peculiar interests. In fact, having one or more areas of narrow, encompassing interest is highly characteristic of those with AS. Parents often ask whether AS is the same thing as â€Å"high-functioning autism. Research studies have addressed this question, and the answer is â€Å"no† (Fombonne, Simmons, Ford, Meltzer Goodman 2001). One main difference is that children with AS tend to have fairly comparable verbal and nonverbal levels of intelligence, while higher functioning (that is, less cognitively impaired) autistic children tend to have nonverbal IQs that are markedly higher than their verbal IQs. Another key feature of AS is the presence of intense, preoccupying interests that generally are unusual in nature and highly restricted and narrow in scope and breadth. An impressive store of factual knowledge is accrued on relatively esoteric topics; however, this knowledge is rarely utilized for functional, socially meaningful purposes. Rather, factual knowledge is pursued for its own intrinsic value to the AS individual. In addition, children and adults with AS tend to be physically awkward, uncoordinated, and poor in judging visual-spatial perspective (often failing to maintain comfortable interpersonal space during social interactions). With regard to neuropsychological functioning, verbal abilities are generally much better developed than are nonverbal abilities (e. . , perceptualmotor, visual-spatial). In a majority of cases impairments are present in executive functions, including working memory, organization, and cognitive-set flexibility. Although children with AS are thought to show no general cognitive delay, there is actually a great deal of variability in the specific abilities of individuals. In spite of mass media suggestions that individuals with AS grow up to be scientists or software engineers, we do not yet have data to support this connection. For most children, the PDDs last a lifetime. Although early intervention for many young children with autistic disorder, Asperegers disorder, and PDDNOS has produced major developmental changes, the technology has not yet reached the point where the majority of children make the degree of change that allows them to blend imperceptibly into their peer group. As a result, although most children with PDDs benefit in important ways from treatment, many still become adults with PDDs or some significant residuals of PDDs. There are no details of what causes PDDs. There appears to be a genetic contribution to at least some kinds of autistic disorder. For example, Fragile X syndrome is a chromosomal disorder than long has been linked to mental retardation and more recently has been shown to be related to autistic disorder. This disorder gets its name from a narrowing near the end of the long arm of the X chromosome that sometimes makes the tip fragile. Fragile X syndrome shows an X-linked (sex gene-linked) recessive pattern of inheritance. As a result, this disorder typically is transmitted to boys by their mothers. Fragile X syndrome accounts for a small but significant number of boys diagnosed with autistic disorder. General support for the notion that the symptoms of autistic disorder reflect underlying physiological dysfunction comes from research showing that autistic disorder occurs more often than would be predicted by chance among children whose mothers had German measles during pregnancy, that these children experienced a higher than expected rate of problems during pregnancy or birth, and that they are at greater risk for seizures than other children. Findings such as these raise important questions about where in the brain abnormalities may occur and how these neurochemical, biochemical, or neurological factors may be linked specifically to the development of the language, social, affective, and behavioral symptoms that characterize autistic disorder and the other PDDs. The process of accurate diagnosis and classification is an essential endeavor in medicine, because it is key to ensuring validity and reliability, enabling etiological research, and identifying effective methods of treatment. Although ASDs are not medical illnesses in the classical sense, they do result from neurodevelopmental abnormalities that affect social, communicative, and behavioral functioning in fundamental ways. The autism is not a unitary condition with a single etiology, pathogenesis, clinical presentation, and treatment approach; rather, it is a group of related conditions that share many clinical features and underlying social-communicative impairments. The fundamental purpose of arriving at an accurate diagnosis is to promote meaningful research that will eventually lead to effective treatment and an ultimate cure. Accurate diagnosis also enables investigators, clinicians, educators, and parents to communicate clearly, effectively, and efficiently. Ideally, a valid and reliable diagnosis should convey a great deal of information about developmental strengths and weaknesses, short- and long-term prognosis, and treatments that are most likely to be effective. Both basic and applied research endeavors are enhanced by improvements in diagnosis and classification. During recent years, efforts have been made to identify ASD as early in life as possible, in order to begin implementing educational and treatment interventions; providing families with education, support, and community resources; and reducing the stress and anxiety families experience as a result of incorrect or misleading diagnoses. The importance of an early diagnosis is supported by findings of improved linguistic, cognitive, and adaptive functioning as a result of intensive early intervention. Studies have begun to appear in the research literature assessing the reliability and stability of autism diagnoses made during the early preschool years. Experienced clinical investigators have demonstrated that an accurate diagnosis of autism can be made in the second and third years of life. However, accuracy depends on the completion of a comprehensive, interdisciplinary assessment, one that includes the use of standardized diagnostic instruments in conjunction with clinical expertise. Nonetheless, even among experienced clinicians and investigators, false positive and false negative diagnoses are sometimes made. Investigators have begun to examine clinical variables that may be predictive of treatment response and general prognosis. For example, Handleman Harris (2001) found that preschool children with autism who exhibited low baseline levels of social avoidance experienced significantly more social and linguistic progress than did their high-avoidance counterparts following 6 months of intensive incidental teaching and pivotal response training (provided in an inclusive setting). A complementary strategy for assessing the validity of AS is to examine the pattern of associated symptomatology. In this regard, a recent study investigated emotional and behavioral disturbance (psychopathology) in 4 to 18-year-olds with HFA and AS. The Developmental Behavior Checklist (DBC), an informant-based instrument completed by parents and teachers, was used to assess psychopathology. The DBC contains the following six subscales: disruptive, self-absorbed, communication disturbance, anxiety, antisocial, and autistic relating. Children and adolescents with AS exhibited high levels of psychopathology, particularly disruptive behavior, anxiety, and problems with social relationships. The best documented approach to the treatment of people with PDDs is a form of behavior therapy called applied behavior analysis. Since the mid-1960s, when Ivar Lovaas and his colleagues demonstrated that children with autism responded to carefully planned applied behavior analytic techniques, there has been extensive research on the use of these methods to treat the PDDs, especially for autistic disorder, Aspergers disorder, and PDDNOS (Durand 1990). Three decades of research have contributed to the development of a substantial array of specific behavioral treatment techniques and of documentation to support the efficacy of these methods in treatment of PDDs. This research also has demonstrated the essential role that parents can play in the treatment of their children by providing consistency of intervention between home and school, or even in some cases as the childs primary therapist.