1. What is a developmental disability?

A developmental disability (DD) is a term used to describe a group of conditions that begin early in childhood and impact a person’s cognitive function, social skills, and ability to live independently (American Association on Intellectual and Developmental Disabilities, n.d.). These limitations typically last throughout a person’s lifetime.

Examples and their Symptoms/Behaviors:

• Intellectual Disability (ID): Characterized by significant limitations in intellectual functioning and adaptive behavior (conceptual, social, practical) [American Psychiatric Association, 2013]. Symptoms may include difficulties with learning, communication, problem-solving, self-care, and social interactions.
• Autism Spectrum Disorder (ASD): Characterized by persistent difficulties with social communication and interaction, along with restricted, repetitive patterns of behavior, interests, and activities [American Psychiatric Association, 2013]. Symptoms can include social awkwardness, communication challenges, repetitive behaviors, and fixated interests.
• Cerebral Palsy (CP): A group of movement disorders that appear in early childhood. Symptoms may include muscle weakness, stiffness, coordination problems, and speech difficulties [National Institute of Neurological Disorders and Stroke, 2020].

Source: American Association on Intellectual and Developmental Disabilities. (n.d.). Intellectual disability. https://www.aaidd.org/intellectual-disability

Diagnosis of Intellectual Disability (ID)

2. DSM-5 Criteria for Intellectual Disability:

The DSM-5 outlines three criteria required for an ID diagnosis [American Psychiatric Association, 2013]:

1. Deficits in Intellectual Functioning: This is assessed by standardized intelligence tests (IQ scores typically below 70-75).
2. Deficits in Adaptive Behavior: Significant limitations in age-appropriate self-care, communication, social participation, and independent living.
3. Onset in Developmental Period: Symptoms emerge before adulthood.

Assessment and Diagnosis:

Diagnosing ID is a multi-step process involving:

• Clinical Interview: Gathering information from parents/caregivers about developmental milestones and current challenges.
• Standardized Testing: IQ tests and assessments of adaptive behavior in various domains (social, practical, communication).
• Medical Evaluation: Ruling out medical conditions that may contribute to intellectual limitations.

Source: American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author.

ADHD vs. ASD: A Comparison

3. Attention-Deficit/Hyperactivity Disorder (ADHD) vs. Autism Spectrum Disorder (ASD):

Etiology: Both have complex and not fully understood causes. Genetics likely play a role in both [American Psychiatric Association, 2013]. Environmental factors may also contribute.

Course:

• ADHD: Symptoms typically persist into adulthood, although some individuals experience improvement.
• ASD: Core features of ASD are lifelong, but the severity and specific challenges can change over time.

Challenges:

• ADHD: Inattention, hyperactivity, impulsivity, difficulty with organization and focus.
• ASD: Social interaction difficulties, communication challenges, repetitive behaviors, sensory sensitivities.

Diagnostic Criteria:

• ADHD: Defined by specific inattention and/or hyperactivity-impulsivity symptoms that cause significant impairment in daily life [American Psychiatric Association, 2013].
• ASD: Characterized by persistent social communication difficulties and restricted, repetitive patterns of behavior [American Psychiatric Association, 2013].

Assessment:

• Both: Clinical interviews, parent/caregiver reports, and standardized assessments specific to each disorder.

Interventions:

• ADHD: Stimulant medication, behavioral therapy, parent training.
• ASD: Social skills training, communication interventions, behavioral therapy, sensory integration therapies.

Sources:

• American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: Author.
• Shaw, P., Eckstrand, M., & Sharp, W. (2012). Attention-deficit/hyperactivity disorder (ADHD) in children and adolescents. The New England Journal of Medicine, 366(14), 1314-1321. https://www.nejm.org/doi/full/10.1056/NEJMcp1307215
• Lai, M. C., Lombardo, M. V., Chakrabarti, B., & Baron-Cohen, S. (2014. Localisation and dissociability of functional brain networks during social and nonsocial perception in autism. Journal of Neuroscience, 34(32), 106