Low Functioning Autism – What Sets it Apart

Low Functioning Autism What Sets it Apart https://www.autismparentingmagazine.com/low-functioning-autismWhat is low functioning autism?

Low functioning autism falls on the more severe end of the autism spectrum. Children diagnosed with this form of autism need more support to complete daily tasks as they struggle to communicate and manage their behaviors. Symptoms are typically identifiable in infancy or early childhood, as those diagnosed will not meet neurodevelopmental benchmarks such as speaking their first words, learning to self-soothe, or forming bonds with family members and other children.

Children with low functioning autism are likely to have a hard time completing activities of daily living (showering, feeding themselves, dressing) alone, and generally require assistance with most activities. In addition to more severe communication and behavioral challenges, low functioning autism may affect a child physically to include common comorbid conditions such as Fragile X syndrome, tuberous sclerosis, and epilepsy. According to the National Institute of Neurological Disorders and Stroke (NINDS), both environment and genetics play a role in autism spectrum disorder (ASD). While they acknowledge autism is a pervasive developmental disorder, NINDS cites an increasing amount of treatment options and resources available, especially for those with severe autism.

Ways low functioning autism differs from high-functioning autism

No two children with ASD will experience the same symptoms; rather, disorders are placed on a spectrum according to severity. The American Psychiatric Association’s Diagnostic and Statistical Manual, Fifth Edition (DSM-5) defines autism spectrum disorders as follows:

“Persistent deficits in social communication and social interaction across multiple contexts…Deficits in social-emotional reciprocity…Deficits in nonverbal communicative behaviors used for social interaction…Deficits in developing, maintaining, and understand relationships.”

Individuals with Asperger’s syndrome, which the DSM-5 now considers “to be related to by distinct from autism,” are the most highly functioning of those with ASD symptoms, while children who have limited abilities to communicate and manage their behavioral are considered to have low functioning autism.

Signs of severe autism

The signs of low functioning autism can be identified as early as infancy with even more noticeable symptoms presented by preschool age. Research scientists at the Mayo Clinic, NINDS, and Nemours list the following as signs:

Impaired Social Interaction

Social interactions for children with severe autism can be difficult to near impossible, depending on the child. Some children will hit early milestones and then experience a regression of social skills previously acquired between the ages of three and five. Others will never develop the skills. Because of their limited emotional range and inability to comprehend the emotions of those with whom they interact, these children sometimes appear to lack empathy making it just as difficult for neurotypical children to initiate interactions with them. Inappropriate responses, such as laughing in serious situations or crying in lighthearted moments, or a complete lack of engagement are hallmark signs of low functioning autism. Most children will lean towards a lack of social responsiveness as seen through little to no eye contact, not acknowledging others’ presences (even the parent or caretakers), and little to no smiling. Children with autism generally have a hard time comprehending facial expressions and therefore do not exhibit many in social situations, but this symptom is exaggerated in low functioning children as their faces often remain blank even as they are experiencing pain.

Social settings involving other children can be particularly difficult for those with low functioning autism as they do not usually engage in imaginative play or make-believe. Some have trouble maintaining the rules of games set by other children, while others find engaging in group play impossible or uninteresting. Initiating conversations can be difficult, and maintaining them even harder; some children seek to communicate in social settings by using single words or short phrases to label an item or make a request.

Change, whether it be in a game or in the home routine, can be difficult for neurotypical children, but is even more challenging for children with low functioning autism. They may become uncooperative, resistant, passive, aggressive, or disruptive. These reactions can make friendships hard to establish and maintain, especially at a young age. Parallel play is an alternative for children who are not overwhelmed by being in the presence of their peers.

Communication Difficulties

Difficulty communicating is one of the first indicators that a child is struggling with low functioning autism. In infancy, autistic children may not babble or point. By age two, they may not be speaking short phrases and may be struggling to communicate their hunger cues, instances of pain, or preferences for activity. They may not respond to their names or acknowledge that they hear their parents or caregivers speaking to them. The child may appear to function in two modes: aloof and enraged. By age four, a child with low functioning autism may remain nonverbal, continue to experience speech delays, or lose any language skills previously acquired.

Verbal children may speak with an abnormal tone or rhythm such as singsong or monotone. They may also develop language skills enough to repeat phrases verbatim, but struggle to contextualize what they are saying. Idioms may be a favorite to repeat, such as “You’re the apple of my eye,” but with little to no understanding of what the phrases mean. They may also take idioms literally, such as “It’s raining cats and dogs,” which may evoke fear or immense confusion.

Low functioning autistic children may also mimic body language and tone without the ability to comprehend the meanings behind them. Other children may continue to have difficulties understanding the most literal speech and directions and find learning new vocabulary difficult. Very few children on the autism spectrum enjoy small talk, but those with low functioning autism will likely find it impossible and incomprehensible. Speaking clearly, literally, and concisely is the best way to speak to a verbal child with low functioning autism.

Obsessive Compulsive Disorder, Anxiety, and Behavior

Children with low functioning autism often exhibit symptoms associated with obsessive compulsive disorder, but their actions are generally driven by sensory overload or deprivation. A child with severe autism may prefer to spend his/her play time excessively lining up toys and objects or playing with them in ways neurotypical individuals find abnormal. The child may exhibit an intense fixation on an object or activity to the point of obsession and have trouble contextualizing his/her toys. For example, the child may be fascinated by details of an object (spinning wheels on a toy car), but unable to understand the bigger picture (the toy car represents a real car). The child may also use toys in ways they were not intended, such as spinning a stationary object or finding more pleasure in turning an electronic toy on and off rather than playing with it. This behavior will generally continue into the primary school age range of six years and up, whereas neurotypical children are able to contextualize their toys by the time they are four- or five-years-old.

Impulse control is a struggle for many children with low functioning autism. They may find it difficult to sit still, and need to move constantly. This can take the form of pacing, repetitive kinesthetic activities, stimming, repetitive speech, or self-injurious behaviors such as skin-picking, pinching, or head-banging. Many children find comfort in highly specific routines or rituals, but are unable to cope with the inevitable changes or disruptions that occur. During these times, existing troublesome behavior may be exaggerated, and the child will likely have trouble controlling his/her behavior. Some children display inappropriate behaviors, like hitting or spitting, even in low-stress environments, with an inability to understand why the behavior is undesirable. They may not be willing to correct their behaviors, manage their impulsivities, or seek their caregivers’ approval.

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Sensory Processing Difficulties

Many parents notice sensory processing difficulties as early as their child’s infancy. Children with low functioning autism may appear stressed by physical touch, such as cuddling or holding, that most of their neurotypical peers find comforting. As the child progresses into primary school, his/her movements may continue to be clumsy, uncoordinated, stiff, or exaggerated long after other children have gained fine and gross motor skills as well as control of their limbs. This delay in acclimating to their own bodies, is often due to a hyper-awareness of movement and the sensations that pulse through their bodies as they move. The transition from walking in humid air versus crisp air, or on carpet versus hard floors, can be overwhelming to a child with autism. These children may also experience profound awareness of sound, smell, touch, or visual stimuli, yet are often oblivious to self-inflicted pain.

Often, triggering stimuli can change seemingly overnight. A favorite food one week may be rejected based on its color or texture the next, just as a favorite shirt that changes texture slightly in the wash could become overwhelmingly uncomfortable. These sensitivities may trigger an angry or frustrated response.

When should I have my child screened for autism?

If you notice two or more of these signs in your child, it is a good idea to take him/her to the pediatrician, especially if typical developmental benchmarks are not being met.

A multi-disciplinary team will help you with a diagnosis for your child. The process will likely start with a questionnaire to evaluate how your child functions at home, in school (if applicable), and in social settings. The evaluation will include a combination of your observations as well as those of your doctor, and possibly your child’s teacher.

If your doctor thinks your child may have an ASD, you and your child will meet with a team including a psychologist and psychiatrist, neurologist, and speech therapist who will conduct cognitive and language testing. A hearing test may also be administered to rule out hearing and auditory processing disorders.

A diagnosis of low functioning autism will be based on three major criteria: firstly, the child’s ability to communicate socially. The team will look at whether the child is verbal or nonverbal and to what extent he/she can communicate his/her needs. Secondly, they will assess the child’s behaviors. Key things they will look for are repetitive movements, self-injurious behaviors, and how repetitive and restrictive these behaviors are. Finally, they will evaluate how much of an impact the behaviors and communication difficulties have on the child’s ability to function.

What are the most common comorbid conditions with severe autism?

Research is currently being conducted by several institutions on the physical issues that many children diagnosed with low functioning autism experience. As listed above, NINDS currently recognizes Fragile X syndrome, tuberous sclerosis, and epilepsy as the three most prevalent co-occurring diagnoses.

Fragile X Syndrome

Fragile X syndrome is a genetic condition that affects development and is often associated with learning disabilities. Common early symptoms include delays in speech and language skills, anxiety, and an inability to sit still, with low impulse control. The National Institute of Health reports that males are more severely affected by Fragile X syndrome and that one-third of those diagnosed will also receive an autism spectrum disorder diagnosis. They also report that most males and half of females diagnosed with Fragile X will exhibit physical features associated with the syndrome, including long, narrow faces, large ears, a prominent jaw and forehead, hyper-flexible fingers, flat feet, and macroorchidism after puberty in males.

The National Human Genome Research Institute recommends special education, anticipatory management, and early intervention to manage symptoms. There are no current specific medications shown to help, but medication to control behavioral issues may be discussed with your child’s pediatrician. Additionally, they suggest addressing vision, hearing, connective tissue, and heart problems with specialists in each field.

Tuberous Sclerosis

Tuberous sclerosis (TS) is a rare genetic condition that causes benign tumors to develop on organs including the skin, brain, heart, eyes, kidneys, and lungs. In 2012, Xin Guo, MD, Wen-Jun Tu, MD, and Xiao-Dong Shi, MD, conducted a study to examine the prevalence rate of TS in individuals also diagnosed with ASD. Over four years, they studied a group of autistic children at the China Rehabilitation Research Center and discovered that one in five (1.17 percent) of the 429 children involved in the study had TS. They concluded that children with low functioning autism were more likely to have TS.

The Mayo Clinic reports no current cure for TS, but suggests talking to your child’s pediatrician about the possible use of antiepileptic drugs to control symptoms.


Epilepsy is a neurological condition that causes electrical communication disruptions between neurons. The result of this disruption is seizure activity. To a bystander, a seizure may look like sudden muscle stiffness, jerking and twitching of limbs and facial muscles, and a distant stare. Before or after seizure activity, the individual may complain of a severe headache and experience confusion.

In 2011, Patrick F. Bolton, PhD, FRCPsych, (et al.) completed a long-term study to assess the rate at which epilepsy occurred in conjunction with an ASD diagnosis. They studied 150 children diagnosed with autism and followed up with the participants after they turned 21. They found that 22 percent of the study’s participants developed seizure activity, mostly after turning 10. They also found that over half of their subjects’ seizures occurred weekly or less frequently and that medication helped control symptoms. Female participants were more likely to develop seizure activities, especially in those with more low functioning autism and weaker verbal skills.

Johns Hopkins urges parents to call 911 if they think their child is experiencing a seizure and to follow up with their pediatricians to discuss medication options as well as dietary therapy, vagus nerve stimulation, and possible surgical options.

Explaining autism to your family and friends

After receiving your child’s diagnosis of autism, you’ll likely think of new questions every day, but one that most parents struggle with at first is how to explain autism to their friends and family. Being honest about your child’s diagnosis and how it affects him/her is important. The more information people have the more likely they are to have successful interactions with your child and know how to support you. However, you are never obliged to reveal more than you wish. Explaining to family and friends how severe autism affects your child in specific situations, and why the child responds the ways he/she does to certain stimuli, can help give others a better understanding of ASD. It’s OK to tell people you are still figuring things out as well. You may wish to tailor your conversations based on whom you are speaking with and his/her knowledge of autism. People will likely have lots of questions. It is OK to tell them that you do not have all the answers, or you may wish to refer them to a helpful article. These conversations will likely be ongoing ones, and each time you start a new conversation, it will likely get easier.

Ways to improve your life with a severe autism diagnosis

Families dealing with a diagnosis of low functioning autism have several options to help improve their everyday lives. A combination of professional support, in-home modifications, educational opportunities, and community support can be beneficial.

Professional Support

After receiving a diagnosis of low functioning autism, your child will likely need to follow up with a team of professionals. This team will include your child’s pediatrician who will monitor your child’s general health and development, lead your child’s team, and make additional recommendations as needed. Other members include an occupational therapist who will help your child achieve as much independence as possible in his/her day-to-day life, a speech therapist who will help your child reach full verbal potential, and a psychiatrist and psychologist who will work to help your child manage emotions and prescribe medication as needed. Other professionals may include a recreational therapist who will provide activity-based intervention, and an autism behavioral therapist who will help your child improve communication and social skills as well as teach him/her ways to manage behavior.

In-Home Modifications

Children with low functioning autism often experience impulse control difficulties or have little understanding of the consequences of dangerous behaviors. Minimizing risk is one of the most important things you can do for your child. Locking up cleaning products or hazardous materials/medications, placing door locks above the reach of your child, and making sure the stove is inaccessible are great ways to start. If your child engages in head-banging, be sure to add padding to areas he/she commonly uses for self-injury, and add cushioning to corners to help keep the child protected. In addition, creating a secure space where he/she has free range can give an empowering sense of independence. It can be beneficial to create a safe and comfortable room with cushions, objects to support over- or under-stimulation (such as a yoga ball chair, soothing bedding, or a weighted blanket) to help your child re-regulate or just have fun. Speak with your child’s pediatrician or occupational therapist to identify potential in-home hazards and safe items most appropriate for your child.

Educational Opportunities

Every child deserves an education, and children with low functioning autism are no exception. Some parents elect to send their children to specialized schools equipped to help children with autism, while others prefer accommodations to be made in an exceptional student education (ESE) classroom. Individualized Education Plans (IEPs) can be made by a school psychiatrist in conjunction with you and your child’s professional team. Your child’s abilities and interests will be evaluated to form a plan that will best cater to your educational goals for your child. Support staff are generally available to help your child throughout the day, and many schools offer one-on-one time for your child with a speech therapist, occupational therapist, recreational therapist, psychologist, and psychiatrist.

Community Support

Support groups are available through most major hospitals and clinics for parents of children with autism. Groups may be led by a therapist, medical student, or another parent. Many people find these groups to be a safe place to voice their frustration and celebrate successes with people who live with similar circumstances. Some hospitals will also offer specialized short-term groups to teach parents practical skills to help their child lead a safe and happy life.

Katherine G. Hobbs is a freelance journalist and university student studying English, with an emphasis on journalism, and psychology. She is interested in the impact of having a special needs child in the family dynamic. Katherine is dedicated to bringing awareness of resources to families and providing help to those who love their autistic children. You can find her online at katherineghobbs.com.

Click Here to Leave a Comment Below
Frederico Pinto ND - August 15, 2017 Reply

What a great, well written article. Thank you.

Kyle Russell - January 12, 2018 Reply

so nice il love

    Naveed Qadri - February 5, 2018 Reply

    Very informative

Alicia - April 30, 2018 Reply

My child has severe autism with learning difficulty, but he was not positive when they tested him for fragile x.

Deb - July 11, 2018 Reply

Great article and very informative. The one thing I would add to this very important discussion about low functioning autism is that there is not one child on the Autism spectrum that presents with the same set of deficiencies. My son most certainly has low functioning Autism but he has fantastic eye contact. Because of his great eye contact the doctors who saw him when he was very young thought he was not even on the Autism spectrum because of this very odd exception to the rule (the rule that says children with low functioning Autism have poor eye contact). Be very careful of what you read. As the parent of an Autistic child, you know your child best. Make sure to express everything to your child’s medical team. Our team does not really consist of doctors as doctors could do little to help our son. He does not have seizures or other conditions that often accompany severe Autism. It is wise to have doctors on the team, yes. When we need a doctor we simply use the local pediatrician (ear infections, acne etc). Luckily we have not needed to used medication as our son’s behavior has been pretty darn good. The one thing to never forget to do with your child is LOVE them so much you can barely stand it. Love them more than anything in the entire world. If you do that, you will be happy and hopefully so will your dear child, no matter how severely Autistic he or she may be! Good luck and try to have fun and laugh as much as you cry!!!

Virginia N Hickey - July 24, 2018 Reply

This is a great article. I was told that my stepson was diagnosed with chromosome 13 deletion, but none of the physical attributes apply to Christopher. So I researched further. I spent years working with adults and children who have developmental disabilities, but had not ever met anyone as severe as Christopher so I wanted to do my research because I wanted to know how to best care for him. I am so thankful for the resources I have come across, but this article is very helpful in helping me form my own conclusion about what is wrong and how I can best support my stepson.

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