Autism and Pervasive Developmental Disorders ppt
Definition of Pervasive Developmental Disorders (PDD) and Autism Spectrum Disorders (ASD)
Pervasive Developmental Disorders (PDD): A group of disorders characterized by severe impairments in social interaction and communication, as well as restricted interests and repetitive behaviours.
Autism Spectrum Disorders (ASD): A broader term that encompasses various disorders on the autism spectrum, including autism and Asperger's syndrome, indicating a range of presentations and severities.
Signature Behaviors for Diagnosis
Discussion of the relationship between the core behaviors that lead to the diagnostic criteria for ASD, including:
Social Interaction Deficits: Difficulty in understanding and engaging in social interactions.
Communication Challenges: Impaired verbal skills or reduced language abilities.
Repetitive Behaviors: Engagement in restricted or repetitive patterns of behavior, including repetitive movements or rituals.
Autistic Spectrum as Extremes of Normal Behavior
Concept that autistic spectrum disorders represent extremes of neurotypical behavior, characterized as neuroatypical, meaning:
Variations in expected social, communicative, and behavioral expression that exist along a continuum.
Neurobiological Evidence for Autism
Highlighting the neurobiological evidence supporting autism as a neurodevelopmental disorder.
Genetic Architecture of Autism
Discussion about the genetic underpinnings of autism, indicating molecular pathways contributing to autism being identified as a “synaptopathy.”
Animal Models: Utilization of models like neurexin and neuroligin to illustrate genetic dysfunction and its implications.
Neuroligin as a Gene Example
Neuroligin illustrates how specific genetic dysfunction can lead to the autism phenotype.
Triad Symptoms: Breakdown of how neuroligin deficiencies impact behaviors observed in ASD.
Experimental Approaches: Methods used to investigate the effect of neuroligin on behavior and biological function.
Therapeutic Strategies for Autism
List of strategies used in treatments for individuals with autism, including:
Behavioral therapies to enhance behavioral plasticity.
Sensory and play therapies encouraging interaction with the environment.
Cognitive therapy to build awareness and strategy development.
Drug therapies targeting:
Neurochemistry underlying autism symptoms:
Examples include Haloperidol (dopamine antagonist) and SSRIs like fluoxetine for repetitive behaviors.
Treatment of related behavioral disorders (e.g. sleep disorders) using propranolol or clonidine.
Organic interventions such as vitamin B6 and B12 to support overall health.
Historical Context of Autism
Leo Kanner (1943): Described children with social dysfunction, poor language skills, and repetitive behaviors leading to the term “autism.”
Leo Asperger (1944): Identified individuals who lacked social skills with special interests, coining the term “autistic psychopathy.”
Drevelopmental Nature of Autism
Autism is a Pervasive Developmental Disorder with behavior sustained through development.
Diagnosis confounded by cognitive variances; high-functioning individuals may present differently than those with mental retardation.
Disorders like Rett’s Syndrome and Fragile X are distinct from autism but influence the diagnostic process.
Diagnostic Criteria in DSM-V
Evolution of autism classification through DSM editions, culminating in a refined definition in DSM-5:
Persistent Deficits in Social Communication and Interaction across multiple contexts.
Symptoms must be evidenced by:
A1: Deficits in social-emotional reciprocity.
A2: Deficits in nonverbal communicative behaviors.
A3: Deficits in developing and maintaining relationships.
Restricted, Repetitive Patterns of Behavior: Exhibiting >2 of the following behaviors:
B1: Stereotyped or repetitive speech/movements/objects.
B2: Excessive adherence to routines.
B3: Highly restricted, fixated interests.
B4: Hyper- or hypo-reactivity to sensory input.
Symptoms must appear in early childhood but may not fully manifest until demands exceed capacities.
Insight on High-Functioning Autism
Acknowledgment that most individuals with an ASD diagnosis are not high-performing, and many face significant daily challenges.
Severity Levels of ASD in DSM-V
Severity Level Descriptions:
Level 3: Requires very substantial support; severe social communication deficits interfere significantly with functioning.
Level 2: Requires substantial support; social communication deficits are noticeable even with supports in place.
Level 1: Requires support; social interaction difficulties can be noticeable without supports.
Neurotypical vs Neuroatypical Behavior
Evidence showing differences in behavior between males and females:
Females generally excel in empathizing, while males in systemizing (e.g., map reading versus verbal fluency).
Autistic traits often differ based on gender, impacting diagnosis.
Hidden Autism in Females
Discussion regarding the challenges of diagnosing autism in females due to:
Bias towards male characteristics in diagnostic tests.
Females’ ability to mask social difficulties, potentially affecting mental health.
Empathizing and Systemizing Quotient
Definitions based on Baron-Cohen’s framework:
Empathizing Quotient: Score of 46 indicates average understanding of feelings and social cues.
Systemizing Quotient: Score of 18 indicates low ability to analyze and explore systems.
Cognitive Neuroscience of Autism
Contribution of Ute Firth in understanding the theory of mind and empathy through testing structures such as the Sally Anne Test to gauge social skills in children.
Nature of the Triad Spectrum
Examination of whether the triad of autism represents a unique spectrum or overlapping traits and the implications for genetic inheritance and diagnosis variance (twin studies).
Biological Basis of Autism
Overview of the neurobiological changes seen in autism:
Abnormal patterns in brain activity documented through electroencephalograms.
Structural changes in brain size and neuronal connections during development.
Developmental Stages in Autism
Description of crucial developmental milestones in brain maturation associated with autism, including:
Cell migration, neurogenesis, synapse formation, and pruning.
Genome-Wide Association Studies (GWAS)
Findings from GWAS highlighting:
Polygenic inheritance of autism with significant familial association.
Linkage studies identifying chromosomal rearrangements and their implications for autism-associated traits.
Genetic Architecture of Autism
More than 1,000 genes implicated in ASD; characterized as strongly genetic with complex interactions.
Underlying Mechanisms of Synaptic Function
Examination of synaptic function and its regulation through key genetic elements involved in formation and stability of synapses.
Neuroligin's Role in Autism
Examination of neuroligin as a central gene implicated in autism and its interactions with neurexin to promote synapse formation.
Translating Understanding to Molecular Mechanisms
Studies indicating mutations in neuroligins NLGN3 and NLGN4 associated with autism diagnoses, emphasizing the complexity of genetic interactions in autism presentation.
Insights from Animal Models
Discussion on animal models of synaptic adhesion and the implications for studying autistic traits:
Observations from neuroligin-3 mutations and their associated behaviors in models of autism.
Therapy/Treatment Approaches in Autism
Overview of various therapeutic interventions:
Emphasis on behavioral therapies to enhance behavior and interaction.
Drug therapy focuses on managing symptoms rather than addressing root causes; common drugs mentioned include Haloperidol, SSRIs, and beta blockers.
Difficulty in establishing efficacy due to the anecdotal nature of many studies and limited clinical trials conducted.