Discovering the world through a different perspective
Autism, or autism spectrum disorder (ASD), refers to a broad range of conditions characterized by challenges with social skills, repetitive behaviors, speech and nonverbal communication. According to the Centers for Disease Control, autism affects an estimated 1 in 59 children in the United States today.
We know that there is not one autism but many subtypes, most influenced by a combination of genetic and environmental factors. Because autism is a spectrum disorder, each person with autism has a distinct set of strengths and challenges. The ways in which people with autism learn, think and problem-solve can range from highly skilled to severely challenged. Some people with ASD may require significant support in their daily lives, while others may need less support and, in some cases, live entirely independently.
Several factors may influence the development of autism, and it is often accompanied by sensory sensitivities and medical issues such as gastrointestinal (GI) disorders, seizures or sleep disorders, as well as mental health challenges such as anxiety, depression and attention issues.
The information below is not meant to diagnose or treat. It should not take the place of consultation with a qualified healthcare professional.
One of the most common questions asked after a diagnosis of autism, is what caused the disorder.
We know that there’s no one cause of autism. Research suggests that autism develops from a combination of genetic and nongenetic, or environmental, influences.
These influences appear to increase the risk that a child will develop autism. However, it’s important to keep in mind that increased risk is not the same as cause. For example, some gene changes associated with autism can also be found in people who don’t have the disorder. Similarly, not everyone exposed to an environmental risk factor for autism will develop the disorder. In fact, most will not.
Autism’s genetic risk factors
Research tells us that autism tends to run in families. Changes in certain genes increase the risk that a child will develop autism. If a parent carries one or more of these gene changes, they may get passed to a child (even if the parent does not have autism). Other times, these genetic changes arise spontaneously in an early embryo or the sperm and/or egg that combine to create the embryo. Again, the majority of these gene changes do not cause autism by themselves. They simply increase risk for the disorder
Autism’s environmental risk factors
Research also shows that certain environmental influences may further increase – or reduce – autism risk in people who are genetically predisposed to the disorder. Importantly, the increase or decrease in risk appears to be small for any one of these risk factors:
- Advanced parent age (either parent)
- Pregnancy and birth complications (e.g. extreme prematurity [before 26 weeks], low birth weight, multiple pregnancies [twin, triplet, etc.])
- Pregnancies spaced less than one year apart
- Prenatal vitamins containing folic acid, before and at conception and through pregnancy
No effect on risk
Vaccines. Each family has a unique experience with an autism diagnosis, and for some it corresponds with the timing of their child’s vaccinations. At the same time, scientists have conducted extensive research over the last two decades to determine whether there is any link between childhood vaccinations and autism. The results of this research is clear: Vaccines do not cause autism. The American Academy of Pediatrics has compiled a comprehensive list of this research.
Differences in brain biology
How do these genetic and nongenetic influences give rise to autism? Most appear to affect crucial aspects of early brain development. Some appear to affect how brain nerve cells, or neurons, communicate with each other. Others appear to affect how entire regions of the brain communicate with each other. Research continues to explore these differences with an eye to developing treatments and supports that can improve quality of life.
- social communication challenges and
- restricted, repetitive behaviors.
In autism, these symptoms
- begin in early childhood (though they may go unrecognized)
- persist and
- interfere with daily living.
Specialized healthcare providers diagnose autism using a checklist of criteria in the two categories above. They also assess symptomseverity. Autism’s severity scale reflects how much support a person needs for daily function.
Many people with autism have sensory issues. These typically involve over- or under-sensitivities to sounds, lights, touch, tastes, smells, pain and other stimuli.
Autism is also associated with high rates of certain physical and mental health conditions.
- Spoken language (around a third of people with autism are nonverbal)
- Eye contact
- Facial expressions
- Tone of voice
- Expressions not meant to be taken literally
- Recognizing emotions and intentions in others
- Recognizing one’s own emotions
- Expressing emotions
- Seeking emotional comfort from others
- Feeling overwhelmed in social situations
- Taking turns in conversation
- Gauging personal space (appropriate distance between people)
- Repetitive body movements (e.g. rocking, flapping, spinning, running back and forth)
- Repetitive motions with objects (e.g. spinning wheels, shaking sticks, flipping levers)
- Staring at lights or spinning objects
- Ritualistic behaviors (e.g. lining up objects, repeatedly touching objects in a set order)
- Narrow or extreme interests in specific topics
- Need for unvarying routine/resistance to change (e.g. same daily schedule, meal menu, clothes, route to school)
The timing and intensity of autism’s early signs vary widely. Some infants show hints in their first months. In others, behaviors become obvious as late as age 2 or 3.
Not all children with autism show all the signs. Many children who don’t have autism show a few. That’s why professional evaluation is crucial.
The following may indicate your child is at risk for an autism spectrum disorder. If your child exhibits any of the following, ask your pediatrician or family doctor for an evaluation right away:
By 6 months
- Few or no big smiles or other warm, joyful and engaging expressions
- Limited or no eye contact
By 9 months
- Little or no back-and-forth sharing of sounds, smiles or other facial expressions
By 12 months
- Little or no babbling
- Little or no back-and-forth gestures such as pointing, showing, reaching or waving
- Little or no response to name
By 16 months
- Very few or no words
By 24 months
- Very few or no meaningful, two-word phrases (not including imitating or repeating)
At any age
- Loss of previously acquired speech, babbling or social skills
- Avoidance of eye contact
- Persistent preference for solitude
- Difficulty understanding other people’s feelings
- Delayed language development
- Persistent repetition of words or phrases (echolalia)
- Resistance to minor changes in routine or surroundings
- Restricted interests
- Repetitive behaviors (flapping, rocking, spinning, etc.)
- Unusual and intense reactions to sounds, smells, tastes, textures, lights and/or colors
If you have concerns, get your child screened and contact your healthcare provider
The M-CHAT (Modified Checklist for Autism in Toddlers ™) can help you determine if a professional should evaluate your child. This simple online autism screen, available on our website, takes only a few minutes. If the answers suggest your child has a high probability for autism, please consult with your child’s doctor. Likewise, if you have any other concerns about your child’s development, don’t wait. Speak to your doctor now about screening your child for autism.
A diagnosis of autism is an important turning point in a long journey to understand your child’s world. Autism Speaks has many resources for families whose children have recently received a diagnosis.
Are you an adult or teen?
Do you suspect that your feelings and behaviors involve autism? Many people who have milder forms of autism go undiagnosed until adulthood. Find out more in our guide: “Is it Autism and If So, What Next?”
Taken from, https://www.autismspeaks.org/what-autism