Conditions comorbid to autism spectrum disorders

There are many conditions comorbid to autism spectrum disorders, ranging from concurrent psychiatric conditions and neuroinflammation to a variety of colon and digestive disorders, which afflict upwards of half of individuals with autistic conditions. However, autism and other autistic spectrum diagnoses, including Asperger syndrome, are diagnosed strictly as a cognitive disability, as a brain disorder that begins in early childhood, persisting throughout adulthood, and affecting three crucial areas of development: communication, social interaction and creative or imaginative play.

Bowel disease
It has been claimed that up to fifty percent of children with autism experience persistent gastrointestinal tract problems, ranging from mild to moderate degrees of inflammation in both the upper and lower intestinal tract. This has been described as a syndrome, autistic enterocolitis, by Dr. Andrew Wakefield; this diagnostic terminology, however, has been questioned by medical experts. Constipation, often with overflow, or encopresis, is often associated with developmental disorders in children, and is often difficult to resolve, especially among those with behavioral and communication problems.

Depression and anxiety disorders
Depression and its cousin, anxiety, may be the most common comorbid disorders accompanying autism, affecting over half of all people with Asperger syndrome (AS). Many times the depression is caused more by society's attitudes and behaviors toward autistics than by the autism itself. Depression might also be related to Seasonal Affective Disorder.

Fragile X syndrome
Fragile X syndrome is the most common inherited form of mental retardation. It was so named because one part of the X chromosome has a defective piece that appears pinched and fragile when under a microscope. Fragile X syndrome affects about two to five percent of people with ASD. It is important to have an autistic checked for Fragile X, especially if the parents are considering having another child. If one child has Fragile X, there is a one-in-two chance that boys born to the same parents will have Fragile X (see Mendelian genetics). Other members of the family who may be contemplating having a child may also wish to be checked for the syndrome.

Hyperactivity and attention abnormalities
Attention-deficit hyperactivity disorder (ADHD) is one of the most commonly diagnosed and controversial mental disorders among children, and is increasingly recognized as afflicting adults as well. Its symptoms include inattention, hyperactivity, and impulsivity. According to sources such as the CDC, the causes are currently unknown, and it is thought that the term covers a variety of related disorders. There is no single medical test that can accurately diagnose ADHD, though there are assessment tools.

Mental retardation
Many autistic children have some degree of mental impairment. When tested, some areas of ability may be normal or superior, while others may be especially weak. For example, an autistic child may do well on the parts of the test that measure visual skills but earn low scores on the language subtests.

Mental retardation isn't a mandatory feature of autism. In fact, most people with autism have at least "normal" results on intelligence test. Some are Mensa members. IQ test results are much more uneven in the sub-categories than normal, frequently showing a peak in visuo-spatial tasks or rote memory. Because of this an autistic may have much more skill in doing certain things than his IQ seems to indicate, and when taken to the extreme it is called being an autistic savant.

Neuroinflammation and immune disorders
The role of the immune system and neuroinflammation in the development of autism is controversial. Until recently, there was scant evidence supporting immune hypotheses, but research into the role of immune response and neuroinflammation may have important clinical and therapeutic implications. The exact role of heightened immune response in the central nervous system (CNS) of patients with autism is uncertain, but may be a primary factor in triggering and sustaining many of the comorbid conditions associated with autism. Recent studies indicate the presence of heightened neuroimmune activity in both the brain tissue and the cerebrospinal fluid of patients with autism, supporting the view that heightened immune response may be an essential factor in the onset of autistic symptoms.

Nonverbal learning disorder
See Nonverbal learning disorder.

Obsessive-compulsive disorder
Obsessive-compulsive disorder is characterized by recurrent obsessional thoughts or compulsive acts.

Obsessional thoughts are ideas, images or impulses that enter the individual's mind again and again in a stereotyped form. They are almost invariably distressing (because they are violent or obscene, or simply because they are perceived as senseless) and the sufferer often tries, unsuccessfully, to resist them. They are, however, recognized as the individual's own thoughts, even though they are involuntary and often repugnant.

Compulsive acts or rituals are stereotyped behaviours that are repeated again and again. They are not inherently enjoyable, nor do they result in the completion of inherently useful tasks.

It must be recognized that this is different from the obsessions that are a feature of autistic spectrum disorders in that the obsessions are not enjoyable or in any way beneficial, which can sometimes be the case with autism, for instance an obsession to study an interest.

Seizures
One in four autistic children develops seizures, often starting either in early childhood or adolescence. Seizures, caused by abnormal electrical activity in the brain, can produce a temporary loss of consciousness (a "blackout"), a body convulsion, unusual movements, or staring spells. Sometimes a contributing factor is a lack of sleep or a high fever. An EEG can help confirm the seizure's presence.

In most cases, seizures can be controlled by a number of medicines called anticonvulsants. The dosage of the medication should be adjusted carefully so that the least possible amount of medication will be used to be effective.

Sensory problems
Many autistic people are highly attuned or even painfully sensitive to certain sounds, textures, tastes, and smells. Some people find the feel of clothes, or certain kind of fabrics, touching or rubbing against their skin to be almost unbearable. Some 'everyday' sounds&#8212;a vacuum cleaner, a ringing telephone, a sudden storm, even the sound of waves lapping the shoreline&#8212;may cause them to cover their ears or scream. Hyposensitivity is also possible; sounds, tastes, smells, etc. that are perceived as overwhelming or uncomfortable by most may be enjoyed by an autistic person.

In autism, the brain seems unable to balance the senses appropriately. Some autistic people are oblivious to extreme cold or pain. An autistic person may fall and break an arm, yet never cry. Another may bash his head against a wall and not wince, but a light touch may make him scream with alarm. The brain seems to not be able to screen out background stimuli while admitting what is important, so the autistic may have to deal with overwhelming amounts of sensory input day and night. A person who doesn't cry out may feel pain, but his brain may not connect the pain to the need for making sounds.

Autistic babies are often observed to stiffen when held. This is due to the sensory overload discussed above, and the stiffening is a coping mechanism which also occurs in adults. Because sensory overload occurs from birth, the coping behaviour is notable as one of the earliest observable symptoms of autism. However, it is not universal among autistics. There is great variation in the susceptibility to sensory overload.

Tuberous sclerosis
Tuberous sclerosis is a rare genetic disorder that causes benign tumors to grow in the brain as well as in other vital organs. It has a consistently strong association with the autistic spectrum. One to four percent of autistic people also have tuberous sclerosis.

Treatment concerns
If a comorbid disorder is present in an autistic, it often cannot be treated in the same manner as when it is present in a neurotypical. For many types of mood, movement and sensory problems, it is generally agreed that smaller amounts of medications work for persons with autism. Larger amounts just cause additional problems. The reason probably has to do with the structural neurology of autism &mdash; if the difficulties are caused by structure and genetics, not by the typical "chemical imbalance," then chemicals won't affect them in the usual, accepted ways.

Some sources indicate autistics have a greater sensitivity to neuroleptics compared to neurotypicals, and that tricyclics should be used with great care, if at all. Many autistics are hyperserotonemic, and the use of the most common type of antidepressant (SSRIs) can cause serotonin syndrome. In this case, tianeptine may be a better alternative, or medication which does not affect serotonin at all (e.g. NARI, MAOI).