Neuro Bio Of Disease (ASD)
Overview
• ASD is a developmental disorder that affects communication and behavior • Symptoms generally appear in the first 2 years of life • According to DSM-5, people with ASD have:
• Difficulty with communication and interaction with other people • Restricted interests and repetitive behaviors • Symptoms that hurt the person’s ability to function properly in school, work, and
other areas of life
• Autism is a “spectrum” disorder because there is great variation in type and severity of symptoms
NIMH
Signs and Symptoms
• Social communication/interaction behaviors: • Making little or inconsistent eye contact • Tending not to look at or listen to people • Rarely sharing enjoyment of objects or activities by pointing or showing things to others • Failing to, or being slow to, respond to someone calling their name or to other verbal attempts
to gain attention
• Having difficulties with the back and forth of conversation • Often talking at length about a favorite subject without noticing that others are not interested
or without giving others a chance to respond
• Having facial expressions, movements, and gestures that do not match what is being said • Having an unusual tone of voice that may sound sing-song or flat and robot-like • Having trouble understanding another person’s point of view or being unable to predict or
understand other people’s actions
NIMH
Signs and Symptoms
• Restrictive/repetitive behaviors • Repeating certain behaviors or having unusual behaviors. For
example, repeating words or phrases, a behavior called echolalia • Having a lasting intense interest in certain topics, such as numbers,
details, or facts • Having overly focused interests, such as with moving objects or
parts of objects • Getting upset by slight changes in a routine • Being more or less sensitive than other people to sensory input,
such as light, noise, clothing, or temperature NIMH
Signs and Symptoms
• But there are strengths, too! • Being able to learn things in detail and remember information for
long periods of time
• Being strong visual and auditory learners • Excelling in math, science, music, or art
NIMH
Neuroanatomical and Neurodevelopmental Basis of ASD
Altered brain growth
• One consistent finding in ASD is altered brain growth • The clinical onset of autism appears to occur after two phases of brain growth abnormalities:
1. Reduced head size at birth 2. Then a sudden and excessive increase between 1-2 months and 6-14 months of age
• In addition to these initial two phases, it is also shown that an abnormal pattern of brain growth also occurs in areas of the frontal lobe, cerebellum, and limbic structures between 2-4 years of age • An abnormal slowness in brain growth then follows this initial growth • We know that these regions are intimately involved with developing social, communication, and motor
abilities that are impaired in ASD
