13. Chapter 14— Neurodevelopmental Disorders PDF

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Chantal Arpin-Cribbie...

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Chapter 14— Neurodevelopmental Disorders Changes from DSM-IV to DSM-5 Intellectual Disability ●

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DSM-5 substitutes the category Intellectual Disability (Intellectual Developmental Disorder) for the category previously referred to as Mental Retardation in DSM-IV. Intellectual Disability is the term formally adopted by the American Association on intellectual and Developmental Disabilities and is the term most commonly use in research journals, and by medical, educational, other professionals, and the lay public. DSM-5 replaces the DSM-IV category of “Mental Retardation, Severity Unspecified” with the diagnosis of Global Developmental Delay. This diagnosis is reserved for children under the age of 5 when clinical severity level cannot be reliably assessed during early childhood. The diagnosis applies to children who fail to meet developmental milestones in several areas of intellectual functioning but who are unable or too young to participate in systematic/standardized assessments of intellectual functioning. This diagnosis requires reassessment following a period of time. ● It is unethical to issue a standardized test on an individual who cannot perform well on the standardized test due to incapabilities, (example: under light sedation) The DSM-5 defines the various levels of severity for Intellectual Disability (using the Mild, Moderate, Severe, and Profound specifiers) on the basis of adaptive functioning, and not IQ scores. This change was made since it is adaptive functioning that determines what levels of support are required. In addition, measures of IQ scores are less valid/reliable in the lower end and the far upper end of the IQ range.

Autism Spectrum Disorder ●

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The DSM-5 combines four previous diagnoses into Autism Spectrum Disorder, reflecting a general consensus among scientists that Autistic Disorder, Asperger’s Disorder, Childhood Disintegrative Disorder, and Pervasive Developmental Disorder Not Otherwise Specified are actually one condition with different levels of severity. DSM-5 no longer includes the overarching category of Pervasive Developmental Disorders. The genetic syndrome of Rett’s disorder has been removed from DSM-5 but, when present, can be specified as an associated known genetic disorder when a diagnosis of autism spectrum disorder has been made. The DSM-5 specifies three levels of severity for Autism Spectrum Disorder symptoms in relation to the amount of required support in each the two component areas of Social Communication and Restricted, Repetitive Behaviours. This change was made to provide a compact and precise description of the severity of the individual’s current symptoms while recognizing that symptom severity and required support may vary across situations and over time.

Communication Disorders ● ● ● ●

The DSM-5 combines two previous diagnoses into Language Disorder, integrating the often co-occurring Expressive Language Disorder and Mixed Receptive-Expressive Language Disorder. DSM-IV’s Phonological Disorder was renamed Speech Sound Disorder in DSM-5. DSM-IV’s Stuttering was renamed Childhood-Onset Fluency Disorder (Stuttering) in DSM-5. The DSM-5 adds a new communication disorder, Social (Pragmatic) Communication Disorder, which involves persistent difficulties in using verbal and nonverbal communication socially. Some individuals previously diagnosed with Pervasive Developmental Disorder-Not Otherwise Specified (PDD-NOS) in DSMIV may meet criteria for Social Communication Disorder, provided that they do not also display restricted behaviours, interests, and activities.

Specific Learning Disorder ●

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The DSM-5 combines four DSM-IV diagnoses (Reading Disorder, Mathematics Disorder, Disorder of Written Expression, and Learning Disorder Not Otherwise Specified diagnoses) in a single Specific Learning Disorder category. By doing so, the DSM-5 integrates DSM-IV’s frequently co-occurring Reading Disorder, Mathematics Disorder, and Disorder Of Written Expression. However, within the Specific Learning Disorder diagnosis, DSM-5 uses specifiers to designate whether the impairments are in reading, written expression, mathematics or more than one of these areas, and provides

examples of types of deficits for each area.

Motor Disorders ● ●

Stereotypic movement disorder has been more clearly differentiated from body-focused repetitive behaviour disorders that are in the DSM-5 obsessive-compulsive disorder chapter. The DSM-5 Tic Disorders category was changed to include Tourette’s Disorder, Persistent (Chronic) Motor or Vocal Vic Disorder, and Provisional Tic Disorder. The tic criteria have been standardized across all of these disorders.

Attention-Deficit/Hyperactivity Disorder ●

Attention-deficit/Hyperactivty disorder (ADHD) is now included in the DSM-5’s Neurodevelopmental Disorders chapter instead of Attention-Deficit and Disruptive Behaviour Disorders Section of the chapter on Disorders Usually First Diagnosed in Infancy, Childhood, or Adolescence (which was eliminated in DSM-5) ● This was done for two main reasons: ● First, ADHD shares with these other disorders an early onset and persistent course ● Second, ADHD is often associated with disruptions in neurodevelopment and other development problems in language, motor, and social development that overlap with the other neurodevelopmental disorders.

Perspectives: Neurodevelopmental Disorders Developmental Psychopathology ● ● ●

Study of how disorders arise and change with time Childhood is associated with significant developmental changes Disruption of early skills will likely disrupt development of later skills

Development-Related Disorders ● ●

First appear at birth or during youth Some would contend that it is inappropriate to include developmental aberrations and learning disabilities in a list of psychiatric disorders.

Attention Deficit Hyperactivity Disorder ●

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Nature of ADHD ● Central features: ● Inattention, overactivity, and impulsivity ● Associated with behavioural, cognitive, social, and academic problems DSM-5 Symptom Clusters ● Criterion 1: Symptoms of inattention ● Criterion 2: Symptoms of hyperactivity and impulsivity cluster ● Either cluster 1 or 2 must be present for a diagnosis ● Both clusters may be present A behaviour disorder (of childhood) involving problems with inattentiveness and/or hyperactivity-impulsivity ● Inattentiveness ● Carelessness ● Forgetfulness in daily activities ● Commonly lose belongings ● Easily distracted ● Cannot follow through on instructions ● Difficulty organizing tasks ● Impulsivity ● Blurting out answers ● Inability to wait their turn

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● Interrupting or intruding on others Facts and statistics: ● Prevalence: ● Occurs in approximately 5-6% of children ● Symptoms are usually identified in elementary school years ● Many children with ADHD retain impairment into adulthood ● Even those who outgrow ADHD may experience lasting marks on personality, self-esteem, and interpersonal relationships. ● Gender Differences: ● Boys outnumber girls ~4 to 1 ● Girls more likely to present with inattentive features ● Cultural Factors: ● Problem of over-diagnosis of ADHD in North America ● Cultural variation in interpretation of children’s behaviours ● E.g., in the United States, African American and Latino rates of ADHD are lower than for Caucasian individuals. Causes of ADHD ● Genetic contributions: ● ADHD tends to run in families ● Although specific genes have been correlated with ADHD, neither necessary nor sufficient causal factors ● Neurobiological contributions: brain dysfunction and damage ● Yet to identify a precise neurobiological mechanism for ADHD ● Possible? ● Inactivity of the frontal cortex (inhibition, planning, organizing) and basal ganglia ● Abnormal frontal lobe development and functioning ● Volume (size) of brain is slightly smaller ● Inhibition of dopamine gene ● The role of toxins: ● Allergens and food additives do not appear to cause ADHD ● ADHD correlated with maternal smoking during pregnancy ● Psychosocial factors can influence the disorder itself ● Constant negative feedback from teachers, parents, and peers ● Peer rejections and resulting social isolation ● Such factors foster low self-image Biological treatment of ADHD ● Goal of biological treatments ● To reduce impulsivity/hyperactivity and to improve attention ● Stimulant medications ● Goal is to reduce the core symptoms of ADHD ● Examples include Ritalin, Dexedrine, Adderal ● Improve compliance and decrease negative behaviours in many children ● Medications in relation to learning and academic performance ● Beneficial effects are not lasting following drug discontinuation Behavioural treatment ● Involve reinforcement programs ● Aim to increase appropriate behaviours and decrease inappropriate behaviours ● May also involve parent training Combined bio-psych-social treatments ● Are highly recommended

Specific Learning Disorder ●

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Delay or deficit in academic skill evidenced by a difference in ability and achievement on standardized tests. Performance is substantially below what would be expected for others of comparable age, education, and level of intelligence. Whether difficulty with something like math should be considered a psychological disorder is very controversial. Some feel it is inappropriate to include learning difficulties in this diagnostic/classification system. Reading disorder is dyslexia Mathematics disorder is dyscalculia

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Disorder of written expression is dysgraphia Scope of specific learning disorder: ● Problems related to academic performance in reading, mathematics, and writing ● Performance is substantially below what would be expected given person’s age, IQ, education ● May also be accompanied by ADHD Some facts and statistics: ● According to Statistics Canada’s A Profile of Disability in Canada, learning disability is one of the two most common disabilities suffered by children up to 14 years of age. ● More than half of all Canadian school children classified as having a disability have a learning disability. ● Difficulties with reading are the most common of the learning disorders and occur in approximately 5-15% of the general population. ● Mathematics disorder appears in approximately 6% of the population, but we have very limited information about the prevalence of disorder of written expression among children and adults. ● Between 5-15% youth of various ages and cultures ● Boys and girls equally affected ● Related to later development of other mental health problems Biological and psychological causes of learning disorders: ● Genetic and neurobiological contributions: ● Evidence for subtle forms of brain damage is inconclusive ● Overall, genetic and neurobiological contributions are unclear ● Found in identical twins, relatives ● Specific psychosocial contributions are not clearly defined ● Consider role of SES, cultural expectations, parental interactions and expectations, child management practices, support (lack of) provide in school. Treatment of learning disorders ● Requires intense educational interventions ● Remediation of basic processing problems ● E.g., teaching visual skills ● Improvement of cognitive skills ● E.g., instruction in listening ● Targeting behavioural skills to compensate for problem areas ● Data support behavioural educational interventions for learning disorders

Autism Spectrum Disorder ● ● ● ● ●

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Problems occur in language, socialization, and cognition Restricted, repetitive patterns of behaviour Typically before age 3 Impairments present in early children: limit daily functioning Clinical description: ● DSM-5 introduces three levels of severity: ● Level 1: requiring support ● Level 2: requiring substantial support ● Level 3: requiring very substantial support ● Levels are described qualitatively ● Do not have any quantitative equivalents Impairments in social communication and social interaction ● Failure to develop age-appropriate social relationships ● Inability to engage in joint attention ● Disinterested in social situations ● Deficits in nonverbal communication ● Lack prosody Restricted, repetitive patterns of behaviour, interests, or activities ● Stereotyped and ritualistic behaviours ● Rituals often complex ● If rituals are interrupted or prevented, person has a severe tantrum Facts and statistics: ● Autism occurs worldwide ● On March 27, 2014, the CDC released new data on the prevalence of autism in the United States. This surveillance study identified 1 in 68 children (1 in 42 boys and 1 in 189 girls) as having autism

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spectrum disorder (ASD). Male to female estimate 4.5:1 ● More prevalent in females with IQs below 35, and males with higher IQs Symptoms usually develop before 36 months of age 31% have intellectual disabilities (IQ less than 70) Better language skills predicts better prognosis

Causes of Autism Spectrum Disorder ●

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Genetic component ● ASD has a genetic component (moderate genetic heritability) ● The exact genetic contribution is unknown ● E.g., families with one child with autism (DSM-IV) have a 3% to 5% risk of having another child with the disorder Neurobiological ● Evidence of brain damage is derived from the observation that 3 of 4 people with autism (DSM-IV) have some level of intellectual disability ● 30-75% display neurological abnormalities such as clumsiness or abnormal posture or gait ● Fewer neurons in amygdala ● Organic (brain) damage ● Lower levels of oxytocin in blood Early and more recent contributions ● Historical views ● Bad parenting ● Such parents were thought to be perfectionistic, cold, and aloof. Later research has contradicted this view. ● Current understanding of ASD ● Parents of individuals with ASD may not differ substantially from parents of children without disabilities ● Medical conditions—not always associated with autism ● ASD has a genetic component that is largely unclear ● Neurobiological evidence for brain damage—link with intellectual disability? ● Cerebellum size—reduced in persons with autism (DSM-IV) ● Psychosocial contributions are unclear

Treatment ●

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Psychosocial “behavioural” treatments ● Skill building and treatment of problem behaviours ● Communication and language problems ● Address socialization deficits ● Early intervention is critical Precise biological and medical treatments are generally unavailable ● Medical intervention has little success Integrated treatments: the preferred model ● Focus on children, their families, parents, schools, and the home ● Build in appropriate community and social support

Intellectual Disability (Intellectual Developmental Disorder) ● ● ● ● ● ●

Intellectual functioning significantly below average ● Language and communication impairments Wide range of impairment in daily activities ● Mild to profound Individuals with ID have difficulty learning DSM-5 does not include numeric cut-offs for IQ scores ● Person must have significantly below-average intellectual functioning (IQ 70) Concurrent deficits or impairments in adaptive functioning Age of onset (deficits evident before age 18)

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Degree of disability varies among ID individuals

Some Facts and Statistics ● ● ● ●

About 1-3% of the general population 90% of persons affected are labeled with mild intellectual disability (IQ of 50-70) Intellectual disability occurs more often in males ● Male to female ratio is 1.6:1 Chronic course (people do not “recover”), but prognosis varies greatly from person to person

Etiologic Research ●

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Has identified hundreds of known causes including: ● Environmental (e.g., abuse, deprivation) ● Prenatal (e.g., exposure to disease, drugs, poor nutrition) ● Perinatal (e.g., difficulties during labour and delivery) ● Postnatal (e.g., infections, head injury) Despite the range of known causes, nearly 75% of cases cannot be attributed to any known cause or are thought to be the result of social and environmental influences

Causes ●

Biological contributions: ● Genetic research ● Involves multiple genes, and at times single genes ● Chromosomal abnormalities ● Down syndrome—trisomy 21 ● Fragile X syndrome—abnormality on X chromosome ● Maternal age and risk of having a Down’s baby ● Increases with age

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Parallels treatment of autism spectrum disorder or learning disorder ● Teach needed skills to foster productivity and independence ● Educational and behavioural management ● Living and self-care skills via task analysis ● Communication training—often most challenging treatment target ● Community and supportive interventions Persons with intellectual disability can benefit from such interventions

Prevention of Neurodevelopmental Disorders ●

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Eugenics: sterilization ● Eugenics was a very controversial movement involving applications of genetics knowledge at the time, for which the goal was to improve the human race through better breeding. ● Eugenics advocates argued for the prevention of ID through sexual sterilization of individuals with ID Early intervention ● Current efforts to prevent neurodevelopmental disorders are in their early stages. One such effort— early intervention—has been described for ASD and appears to hold considerable promise for some children Behavioural intervention...