Neurodevelopmental Disorders PDF

AS2402 NEURODEVELOPMENTAL DISORDERS Neurodevelopmental disorders are conditions that typically emerge during childhood and persist into adulthood. They have a neurological basis and significantly impact individuals' lives. Understanding early disruptions in development i...

AS2402 NEURODEVELOPMENTAL DISORDERS Neurodevelopmental disorders are conditions that typically emerge during childhood and persist into adulthood. They have a neurological basis and significantly impact individuals' lives. Understanding early disruptions in development is crucial for effective intervention. Attention-Deficit/Hyperactivity Disorder The primary characteristics of this disorder include a pattern of inattention (such as being disorganized or forgetful about school or work-related tasks) or hyperactivity and impulsivity. As a result, in people with ADHD, their tasks are often unfinished, and they often seem not to be listening when someone else is speaking. In addition to this serious disruption in attention, some people with ADHD display motor hyperactivity. Children with this disorder are often described as fidgety in school, and unable to sit still for more than a few minutes. In addition to hyperactivity and problems sustaining attention, impulsivity—acting apparently without thinking—is a common complaint made about people with ADHD. These characteristics can significantly disrupt academic efforts, as well as social relationships. For ADHD, DSM-5 differentiates two categories of symptoms: Inattention: Individuals might seem to disregard what others say, misplace important school materials like assignments, books, or tools, and overlook details, leading to careless errors. Hyperactivity and impulsivity: Hyperactivity involves constant fidgeting, difficulty sitting still, and a perpetual state of activity. Impulsivity includes answering questions prematurely and struggling to wait for their turn. Either the first (inattention) or the second and third (hyperactivity and impulsivity) set of symptoms must be present for someone to be diagnosed with ADHD. Causes ADHD is highly influenced by genetics, with environmental factors playing a smaller role. Research suggests that multiple genes are responsible for ADHD, with mutations like copy number variants (CNVs) disrupting development. Genes associated with dopamine, norepinephrine, serotonin, and gamma-aminobutyric acid (GABA) are implicated in ADHD. Specific genetic defects are linked to cognitive processes like attention, working memory, inattentiveness, and impulsivity, aiding in understanding the disorder and designing interventions. While genetics play a significant role, environmental factors such as maternal smoking during pregnancy, maternal stress, alcohol use, and parental marital instability also contribute to ADHD risk. Brain scans show differences in brain volume and areas involved in self-organizational abilities in individuals with ADHD. Medication has been found to have a "growth-enhancing effect" on brain development in children with ADHD. Controversies surround the role of toxins like food additives and pesticides in ADHD, with some research suggesting a possible impact on behavior. Psychological and social factors also influence ADHD, affecting the child's self-esteem and social interactions, which can have lasting effects into adulthood. 12 Handout 1 *Property of STI Page 1 of 8  AS2402 Treatment Treatment for ADHD involves a combination of psychosocial and biological interventions aimed at reducing symptoms and improving overall functioning. Psychosocial treatments, including behavioral parent training, classroom management, peer interventions, organization training programs, parent education programs, and social skills training, focus on enhancing academic performance, reducing disruptive behavior, and improving social skills. These interventions are tailored to individual needs and target both short-term symptom management and long-term improvement of academic performance and social skills. In addition to psychosocial interventions, biological treatments play a crucial role in managing ADHD symptoms. Medications, primarily stimulants like methylphenidate (Ritalin, Adderall), and non-stimulant medications such as atomoxetine (Strattera), effectively reduce core symptoms of impulsivity and hyperactivity while improving attention skills. However, medication may not be effective for all individuals and may cause side effects in some cases. To maximize treatment efficacy, a combined approach involving both medication and psychosocial interventions is often recommended. Research suggests that this combined approach is more effective than either treatment alone for improving ADHD symptoms, social skills, and academic performance. Despite advancements in treatment options, ADHD remains a significant challenge for individuals, families, and the educational system. Ongoing research is needed to further understand the most effective treatment strategies for ADHD. Specific Learning Disorder Specific learning disorder is characterized by a notable gap between an individual's academic performance and the expected level for their age, often termed "unexpected underachievement." The criteria specify that the person must perform academically well below the typical level for someone of the same age, cognitive ability (measured by an IQ test), and educational background. In addition, a diagnosis of specific learning disorder requires that the person’s disability not be caused by a sensory difficulty, such as trouble with sight or hearing, and should not be the result of poor or absent instruction. Historically, specific learning disorders were identified by a significant IQ-achievement score gap. Due to controversies and delays in diagnosis, many clinicians now use the response to intervention approach. This method identifies learning disorders based on a child's poor response to effective interventions, such as early reading programs, compared to peers. This provides an early warning system and focuses on providing effective instruction. Causes The causes of specific learning disorder (SLD) involve genetic, neurobiological, and environmental factors. Genetic research suggests that SLDs run in families, with different genes affecting learning across domains such as reading, mathematics, and writing. Subtle brain impairments, including structural and functional differences, are implicated in SLDs, with specific brain areas involved in problems like dyslexia and mathematics disorder. 12 Handout 1 *Property of STI Page 2 of 8  AS2402 Environmental factors, such as home reading habits, can significantly influence outcomes, suggesting that early interventions like reading to at-risk children can mitigate the impact of genetic influences. Cultural and linguistic differences also play a role in the prevalence of SLDs, with research suggesting that the complexity of written language may contribute to differences in diagnosis rates among English-speaking countries. Psychological and motivational factors, along with socioeconomic status, cultural expectations, parental interactions, and school support, also influence the outcome of individuals with SLDs. Despite obstacles, supportive environments and reinforcement of psychological factors can help individuals with SLDs. Treatment Treatment for specific learning disorders primarily involves educational interventions, with biological treatments reserved for individuals with comorbid ADHD. Educational efforts focus on specific skills instruction, such as vocabulary and reading comprehension, and strategy instruction, which improves cognitive skills like decision-making and critical thinking. Direct Instruction, a research-supported program, has shown significant improvement in academic skills for children with specific learning disorders. Brain-imaging studies have revealed that these educational interventions can reshape the brain's functioning. For instance, children with reading difficulties who underwent intensive training showed improvements in reading skills and changes in brain activity, bringing their brain functioning closer to that of their peers without reading difficulties. Autism Spectrum Disorder ASD is a neurodevelopmental disorder that affects social perception and interaction. DSM-5 merged various disorders previously included under the umbrella term “pervasive developmental disorders” like autistic disorder, Asperger's disorder, and childhood disintegrative disorder into this single category. Rett disorder, characterized by hand wringing and poor coordination, is now diagnosed as ASD with the qualifier "associated with Rett syndrome" or "associated with MeCP2 mutation" (the gene involved in Rett syndrome). The term "not otherwise specified" was removed. DSM-5 introduced a new disorder, social (pragmatic) communication disorder, characterized by social communication difficulties without restricted, repetitive behavior patterns seen in ASD. These individuals struggle to learn social communication rules, such as avoiding interruptions, speaking at an appropriate volume, and listening to others. Certain individuals previously diagnosed with pervasive developmental disorder—not otherwise specified may fall into this category. Two major characteristics of ASD are expressed in DSM-5: 1. Impairments in social communication and social interaction One of the defining characteristics of people with ASD is that they do not develop age-appropriate social relationships. Difficulties with social communication and interaction are characterized by three key aspects: issues with social reciprocity (difficulty engaging in back-and-forth social interactions), nonverbal communication, and initiating and maintaining social relationships. All three aspects must be present for a diagnosis of ASD. 12 Handout 1 *Property of STI Page 3 of 8  AS2402 Social reciprocity for individuals with more severe symptoms of ASD (previously diagnosed with autistic disorder) struggle with joint attention. Joint attention involves sharing interest in objects or activities with others. For example, when a toddler without ASD sees a toy she likes, she might look at her mother, smile, look at the toy, and then look at her mother again. This social act demonstrates both interest in the toy and the wish to share that interest with another person. Eye-tracking studies show that individuals with ASD may not be interested in social situations. Deficits in nonverbal communication in individuals with severe forms of ASD can include not pointing to desired objects, while those with milder forms may stand too close to others. Additionally, individuals with milder forms of ASD may lack appropriate facial expressions or tone of voice, also known as prosody. Approximately 10% to 33% of individuals with ASD do not develop sufficient speech proficiency to communicate their needs effectively. Some individuals repeat the speech of others, a pattern called echolalia, while others engage in one-sided conversations about their restricted interests. 2. Restricted, repetitive patterns of behavior, interests, or activities The more notable characteristics of ASD include restricted, repetitive patterns of behavior, interests, or activities. This intense preference for consistency is known as the maintenance of sameness. People with ASD often spend hours engaged in stereotyped and ritualistic behaviors, such as spinning in circles, waving their hands in front of their eyes with their heads tilted to one side, or biting their hands. For individuals with less severe ASD, these behaviors can take the form of an almost obsessive interest in certain, very specific subjects (such as following airline schedules or memorizing ZIP codes). This tendency to be much more interested in esoteric facts than in people further helps to interfere with social relationships. To accommodate the range of difficulties in the two symptom clusters (social/communication interaction and restricted, repetitive patterns of behavior, interests, or activities), DSM-5 introduced three levels of severity: Level 1 - “Requiring support” Level 2 - “Requiring substantial support” Level 3 - “Requiring very substantial support.” Separate ratings are provided for social/communication interaction and for restricted interests and repetitive behaviors. Each level of support is described qualitatively and, as yet, has no quantitative equivalent. This subjectivity makes assigning the appropriate level of support needed somewhat problematic if the person with ASD does not perform at the extreme ends of these categories. Causes ASD's causes are complex and multifaceted, with a blend of biological and psychosocial factors. Historically, ASD was mistakenly linked to parental behavior. Early theories blamed parents for their children's symptoms, leading to unnecessary guilt and stigma. However, modern research has debunked these notions, showing that parents of individuals with autism are not substantially different from other parents. Some early theories about ASD were based on language patterns, particularly the avoidance of first-person pronouns. However, later research revealed that self-awareness develops in individuals with ASD, albeit at a different pace. While media often portray individuals with ASD with extraordinary cognitive abilities, such as 12 Handout 1 *Property of STI Page 4 of 8  AS2402 those seen in the movie Rain Man, these abilities are not universal. Only around one third of individuals with ASD display such skills, primarily in areas like music, art, and mathematics. These abilities are typically accompanied by superior working memory and focused attention. Similarly, behaviors like echolalia (repeating words or phrases) and self-injurious behavior are not unique to ASD. They are observed in typically developing children, albeit in milder forms. This understanding has helped clinicians differentiate between myths and realities about ASD and emphasized that social deficiencies are the primary distinguishing characteristic of individuals with ASD. Genetic factors play a significant role, with a complex interplay of multiple genes implicated in the disorder's development. Families with one child with ASD have a much higher likelihood of having another affected child. Research also suggests associations between ASD and genetic factors related to oxytocin, a hormone crucial for social bonding. Advanced parental age, particularly in fathers, is linked to an increased risk of ASD, possibly due to de novo mutations in sperm or eggs. Neurobiological studies point to abnormalities in brain structures like the amygdala, potentially affecting social behaviors and emotional regulation in ASD individuals. The neuropeptide oxytocin, vital for social interaction, shows altered levels in individuals with ASD, suggesting its role in social cognition. Controversial theories linking childhood vaccines, particularly those containing thimerosal, to ASD have been refuted by large-scale epidemiological studies. Treatment Treatment research for ASD primarily focuses on children with severe forms of the disorder. While no completely effective treatment exists, efforts concentrate on enhancing communication and daily living skills and reducing problem behaviors like tantrums and self-injury. Initially, psychodynamic treatments aimed at ego development were common, but they proved ineffective. Greater success has been achieved with behavioral approaches focusing on skill building. Communication and language issues are central in ASD treatment. Early interventions have focused on teaching children meaningful speech, employing methods like shaping and discrimination training. Naturalistic teaching strategies, like incidental teaching and pivotal response training, have been introduced to typical settings, enhancing social communication skills. Social skills training, including conversation and question-asking, is challenging but crucial for individuals with ASD. Peer-assisted approaches have shown promise in improving socialization skills. Early intensive behavioral treatments, provided for 40 or more hours per week, have significantly improved intellectual and educational functioning. Interventions targeting joint attention and play skills have shown promising results in early intervention programs. These skills are crucial for the development of more sophisticated social behaviors. Some research suggests that intensive early behavioral interventions may help in normalizing brain development in children with ASD. Given their affinity for technology, children with ASD have shown interest in virtual reality-based social skills learning environments. These innovative approaches could be instrumental in improving social skills among individuals with ASD. Medical interventions have had limited success in addressing the core symptoms of ASD, such as social and language difficulties. While pharmacological treatments like major tranquilizers and serotonin-specific 12 Handout 1 *Property of STI Page 5 of 8  AS2402 reuptake inhibitors can help reduce agitation, they may not be effective for everyone with ASD. Current research aims to find pharmacological treatments targeting specific ASD symptoms. Early intervention for young children with ASD holds promise for significant improvements in core symptoms. For older children and those not responsive to early intervention, a combination of approaches is recommended. School education with special psychological support, behavioral therapies, and pharmacological treatments can help address communication and socialization issues. Parents also require support due to the demands of caring for children with ASD. As individuals with ASD grow older, efforts focus on integrating them into the community, often through supported living arrangements and work settings, depending on their abilities. Intellectual Disability (Intellectual Developmental Disorder) ID is a disorder evident in childhood as significantly below-average intellectual and adaptive functioning. People with ID experience difficulties with day-to-day activities to an extent that reflects both the severity of their cognitive deficits and the type and amount of assistance they receive. DSM-5 identifies difficulties in three domains: Conceptual (skill deficits in areas such as language, reasoning, knowledge, and memory) Social (problems with social judgment and the ability to make and retain friendships) Practical (difficulties managing personal care or job responsibilities) Language and communication difficulties are common among individuals with ID, with severity varying from mild to severe. IQ scores, although previously used for diagnosis, are no longer the sole criteria. Instead, the DSM-5 emphasizes a comprehensive assessment of intellectual and adaptive functioning. To be diagnosed with ID, a person must exhibit significant atypical intellectual functioning, alongside deficits in adaptive functioning in areas such as communication, self-care, and social skills. These difficulties must be evident before the age of 18. However, the definition of ID remains imprecise and is largely shaped by societal standards. The classification of ID is based on the level of support individuals need, ranging from intermittent to pervasive. Classification systems traditionally categorize ID into four levels: mild, moderate, severe, and profound. However, individuals within each level may have varying abilities and require different levels of support (Holland, 2012). While individuals with severe or profound ID may have limited communication skills and require significant assistance, those with mild or moderate ID may achieve varying degrees of independence depending on their education and available community support. Causes Multiple genetic factors contribute to intellectual disability (ID), including chromosomal disorders (e.g., Down syndrome), single-gene disorders, mitochondrial disorders, and multiple genetic mutations. Single- gene disorders can involve dominant, recessive, or X-linked genes. Chromosomal aberrations lead to intellectual disability. Down syndrome, the most common form, results from an extra 21st chromosome (trisomy 21). For some time, it has been possible to detect the presence of 12 Handout 1 *Property of STI Page 6 of 8  AS2402 Down syndrome—but not the degree of ID—through amniocentesis, a procedure that involves removing and testing a sample of the fluid that surrounds the fetus in the amniotic sac, and through chorionic villus sampling (CVS) in which a small piece of placenta tissue is removed and tested. These types of test are not always desirable because they involve an invasive procedure (inserting a needle that could cause unwanted damage to the developing fetus). Fragile X syndrome, another common cause, involves a mutation on the X chromosome and primarily affects men, causing moderate-to-severe ID. The incidence of Down syndrome is linked to maternal age, with older mothers having a higher risk. Advances in prenatal testing enable early detection of Down syndrome, but do not predict the severity of the disorder. Fragile X syndrome affects approximately 1 in every 4,000 men and 1 in every 8,000 women. Cultural influences that may contribute to ID can include abuse, neglect, and social deprivation. Sometimes referred to as cultural–familial intellectual disability, people with these characteristics are thought to have cognitive impairments that result from a combination of psychosocial and biological influences, although the specific mechanisms that lead to this type of intellectual disability are not yet understood. Fortunately, because of better child-care systems and early identification of potential family difficulties, these cases are rare today. Treatment Biological treatments for intellectual disability (ID) are not yet viable, so interventions focus on teaching individual skills for increased independence and productivity, akin to approaches used for severe autism spectrum disorder. For those with mild ID, interventions often resemble those for learning disorders, targeting specific deficits like reading and writing while providing additional community support. Individuals with severe ID require more extensive assistance but are still encouraged to participate in community life, education, employment, and social relationships. Behavioral techniques, developed since the 1960s, help individuals with even profound disabilities learn self- care skills through task analysis—a process where a skill is broken down into its component parts. Each part is taught sequentially until the individual can perform the skill independently. Positive reinforcement, such as praise or access to desired objects or activities, encourages progress. Communication training is crucial, using strategies ranging from improving articulation to teaching sign language or using augmentative communication methods. Augmentative communication strategies can include picture books, where individuals make requests by pointing to a picture, or computer-assisted devices like tablet computers programmed to produce spoken sentences. These methods help individuals with limited communication skills express themselves, reducing frustration and improving their ability to interact with others. Concerns about aggressive or self-injurious behavior have prompted debates about intervention methods, with alternatives to punishment gaining traction. Supported employment programs help individuals with ID find and maintain competitive jobs, promoting their integration into society. There's been a shift towards teaching these skills within regular classrooms and integrating individuals with ID into the community, suggesting meaningful changes are possible in their lives. 12 Handout 1 *Property of STI Page 7 of 8  AS2402 Communication and Motor Disabilities Childhood-Onset Fluency Disorder: A speech fluency disturbance that includes problems such as repeating syllables or words, prolonging certain sounds, making obvious pauses, or substituting words to avoid difficult-to-articulate ones. Language Disorder: Limited speech in all situations, where expressive language (what is said) is significantly below receptive language (what is understood), with the latter usually being average. Social (Pragmatic) Communication Disorder: Difficulties with the social aspects of verbal and nonverbal communication, including verbosity, prosody, excessive switching of topics, and dominating conversations, without the restricted and repetitive behaviors found in ASD. Tourette’s Disorder: Involuntary motor movements (tics), such as head twitching, or vocalizations, such as grunts, that often occur in rapid succession, come on suddenly, and happen in idiosyncratic or stereotyped ways. Vocal tics often include the involuntary repetition of obscenities. Prevention of Neurodevelopmental Disorders Prevention efforts for neurodevelopmental disorders are in their early stages, but early intervention shows promise, particularly for children at risk for cultural-familial intellectual disability. Programs like Head Start providing educational, medical, and social support for children and their families, with research indicating significant positive outcomes. However, questions remain about how to identify children who will benefit from such programs, when to start, and how long to continue intervention. Advances in genetic screening and technology offer hope for future interventions. For example, research on fragile X syndrome suggests potential early medical interventions. Biomedical advances will require collaboration between medical and psychological researchers to ensure proper treatment. Psychologists play crucial roles in identifying and addressing biological risk factors like malnutrition and toxin exposure, contributing to the prevention of developmental disorders. References American Psychiatric Association. (2022). Diagnostic and Statistical Manual of Mental Disorders (5th Ed., text rev.) Barlow, D., Durand, V., Hofmann, S. (2023). Psychopathology: An Integrative Approach to Mental Disorders (9th Ed). Cengage. 12 Handout 1 *Property of STI Page 8 of 8