High-functioning autism (HFA) is historically an autism classification to describe a person who exhibited no intellectual disability but otherwise showed autistic traits, such as difficulty in social interaction and communication, as well as repetitive, restricted patterns of behavior. The term is often applied to autistic people who are fluently verbal and of at least average intelligence. However, many in medical and autistic communities have called to stop using the term, finding it simplistic and unindicative of the difficulties some autistic people face. HFA has never been included in either the American Psychiatric Association's Diagnostic and Statistical Manual (DSM) or the World Health Organization's International Classification of Diseases (ICD), the two major classification and diagnostic guidelines for psychiatric conditions. The DSM-5-TR subtypes autism into three levels based on support needs. Autism Level 1 has the least support needs and corresponds most closely with the "high-functioning" identifier.

Characterization

The term high-functioning autism was used in a manner similar to Asperger syndrome, another outdated classification. The defining characteristic recognized by psychologists was a significant delay in the development of early speech and language skills, before the age of three years. The term Asperger syndrome typically excluded a general language delay. Other differences noted in features of high-functioning autism and Asperger syndrome included the following:

Comorbidities

See main article: Conditions comorbid to autism There are several comorbidities, the presence of one or more disorders in addition to the primary disorder, associated with high-functioning autism. Individuals with autism spectrum disorders risk developing symptoms of anxiety. While anxiety is one of the most commonly occurring mental health symptoms, children and adolescents with high functioning autism are at an even greater risk of developing symptoms. Other associated conditions of include bipolar disorder and obsessive–compulsive disorder (OCD). In particular the link between HFA and OCD, has been studied; both have abnormalities associated with serotonin. Observable comorbidities associated with HFA include ADHD and Tourette syndrome. HFA does not cause, nor include, intellectual disabilities. This characteristic distinguishes HFA from low-functioning autism; between 40 and 55% of individuals with autism also have an intellectual disability. In addition to mental health disorders, several medical conditions are comorbid to autism. These medical conditions include, but are not limited to: seizure disorders, sleep disorders, gastrointestinal disorders, and hormonal dysfunction. `

Behavior

An association between HFA and criminal behavior is not completely characterized. Several studies have shown that the features associated with HFA may increase the probability of engaging in criminal behavior. While there is still a great deal of research that needs to be done in this area, recent studies on the correlation between HFA and criminal actions suggest that there is a need to understand the attributes of HFA that may lead to violent behavior. There have been several case studies that link the lack of empathy and social naïveté associated with HFA to criminal actions. There is still a need for more research on the link between HFA and crimes, because many other studies point out that most people with ASD are more likely to be victims and less likely to commit crimes than the general population. But there are also small-subgroups of people with autism that commit crimes because they lack understanding of the laws they have broken. Misunderstandings are especially common regarding autism and sex offenses, since many people with autism do not receive sex education.

Cause

Although little is known about the biological basis of autism, studies have revealed structural abnormalities in specific brain regions. Regions identified in the "social" brain include the amygdala, superior temporal sulcus, fusiform gyrus area and orbitofrontal cortex. Further abnormalities have been observed in the caudate nucleus, believed to be involved in restrictive behaviors, as well as in a significant increase in the amount of cortical grey matter and atypical connectivity between brain regions.

Diagnosis and IQ

HFA is not a recognised diagnosis by the American Psychiatric Association or the World Health Organization. HFA was, however, previously used in clinical settings to describe cases of autism spectrum disorder where indicators suggested an intelligence quotient (IQ) of 70 or greater.

Treatment

While there exists no single treatment or medicine for people with autism, there exists several strategies to help lessen the symptoms and effects of the condition. There is however no one size fits all solution, so that the best treatment course is different for each individual. Furthermore, research shows that earlier diagnosis and interventions are more likely to have significant beneficial effects later in life.

Augmentative and alternative communication

Augmentative and alternative communication (AAC) is used for autistic people who cannot communicate orally. People who have problems speaking may be taught to use other forms of communication, such as body language, computers, interactive devices, and pictures. The Picture Exchange Communication System (PECS) is a commonly used form of augmentative and alternative communication with children and adults who cannot communicate well orally. People are taught how to link pictures and symbols to their feelings, desires and observation, and may be able to link sentences together with the vocabulary that they form.

Speech–language pathologists

Speech–language pathologists (SLPs) can help those with autism who need to develop or improve communication skills. People with autism may have issues with communication, or speaking spoken words. According to the ASHA, SLPs can help diagnosing autism as they often are among the earliest practitioners that children with autism see, and help with finding means of communication that better suit the child. They can also counsel caretakers, and accompany people with autism when they transition into adulthood and a work environment, such as help in writing an adequate CV. SLPs may teach someone how to communicate more effectively with others or work on starting to develop speech patterns. SLPs use a variety of therapies depending on the child's needs and practitioner's preferences, usually a mix composed in majority of promising therapies and a few unestablished therapies according to evidence-based guidelines.

Occupational therapy

Occupational therapy helps autistic children and adults learn everyday skills that help them with daily tasks, such as personal hygiene and movement. These skills are then integrated into their home, school, and work environments. Therapists will oftentimes help people learn to adapt their environment to their skill level. This type of therapy could help autistic people become more engaged in their environment. An occupational therapist will create a plan based on a person's needs and desires and work with them to achieve their set goals.

Applied behavioral analysis (ABA)

Applied behavior analysis (ABA) is considered the most effective therapy for autism spectrum disorders by the American Academy of Pediatrics. ABA focuses on reducing negative behaviors while developing common skills such as social skills, play skills, communication skills, self-care skills, vocational skills, adaptive skills, and safety skills. Techniques generally involve encouraging positive behaviors with positive reinforcement while removing reinforcers for negative behaviors. `

Sensory integration therapy

Sensory integration therapy helps people with autism adapt to different kinds of sensory stimuli. Many with autism can be oversensitive to certain stimuli, such as lights or sounds, causing them to overreact. Others may not react to certain stimuli, such as someone speaking to them. Many types of therapy activities involve a form of play, such as using swings, toys and trampolines to help engage people with sensory stimuli. Therapists will create a plan that focuses on the type of stimulation the person needs integration with.

Medication

While there are no medications designed to treat autism, they may be prescribed for conditions which co-occur with autism. Healthcare providers might use medications to reduce a specific behavior, such as self-injury or aggression. The FDA has approved the use of some antipsychotic drugs, such as risperidone and aripiprazole, for treating irritability associated with autism spectrum disorder in children between certain ages. Parents should talk with their child's healthcare providers about any medications for children. Other drugs are often used to help improve symptoms of autism, but they are not approved by the FDA for this specific purpose. Research shows that medication is most effective when used in combination with behavioral therapies. `