Comorbidities

Conditions that are seen more commonly in neurodivergent people.

Whilst neurodivergent conditions such as ADHD, autism, dyspraxia and dyslexia frequently travel alongside each other (known as close cousins), there are many other health conditions that seem to occur more frequently in our community than in the general community. 

These are known as comorbidities or co-existing conditions. It can be helpful to know about these other conditions because they can affect our neurodivergent differences and vice versa. Also, treatment for one might affect or even be detrimental to another. Or the treatment or support for one may well be dependent on the consideration for another. 

Or you may simply be interested in comparing some of these conditions with neurodivergent conditions, especially if there is any doubt or confusion over their diagnosis. 

This list is not exhaustive and we are no means experts in these conditions, but if you wish to find out more about any of them, links are provided where possible. 

Sensory 

Irlen syndrome – Differences with the brain’s ability to process visual information which can affect reading and printed information. It is not easily diagnosed via normal sight checks. 

Prosopagnosia – Also known as ‘face blindness’. A condition where people have great difficulty recognising faces that they have seen before, even many times. In extreme cases, they may have trouble recognising close members of their family. 

Synaesthesia – A condition where two or more senses that are normally experienced separately, are involuntarily joined together. For example, experiencing colour when hearing sounds or reading words. These sensations cannot be turned on or off and synaesthesia isn’t a disease or illness. It is not harmful at all. 

Alexithymia – A difficulty accurately identifying or describing emotions and sensations in ourselves or others. 

Why Doesn’t Standard Talking Therapy Work for Autistic People? Dr Alice Nicholls suggest the problem could be “… that approximately 50% of autistic adults have alexithymia, this means that a significant proportion of autistic people struggle to identify, name and communicate their mood.” 

Sensory processing disorder (SPD) – Also known as sensory integration disorder. A neurological disorder or difference that results from the brain’s inability to integrate certain information received from the body’s sensory systems. The individual reacts in an extreme way to sensory experiences. 

Aphantasia – The term given to the lack of a mind’s eye. People with aphantasia do not think in pictures. They are unable to visualise imagery or conjure a scene in their minds. 

Central auditory processing disorder (CAPD) Also known as auditory processing disorder (APD). People with CAPD can hear, but the brain has trouble processing the sounds. In other words, their actual hearing is fine, the difficulties are in the brain’s processing system where sound is actually filtered and interpreted. This can include problems such as, not being able to differentiate between similar sounds in words, hearing what someone is saying to them but not being able to make sense of it, difficulty blocking out background noise and not being able to tell from which direction a sound is coming from. 

Auditory processing disorder (APD), also known as Central Auditory Processing Disorder (CAPD), refers to a condition that impacts the brain’s ability to filter and interpret sound 

Mental health 

A mental health disorder or psychiatric illness is a condition which causes disturbed behaviour and altered emotional state. For example, depression, bipolar disorder, anxiety disorders, phobias, trauma related illness, addiction and eating disorders. Mental health and physical health are one. The body and the brain are not separate entities. So, it stands to reason that our mental health is greatly affected by all things physical, sensory and so on. And vice versa. So, it is a super important area to take good care of. 

AnxietyThis is almost a given in autism and ADHD. 

DepressionAgain, very common in neurodevelopmental conditions, especially where there is a late diagnosis or a lack of support. Also common in many chronic health conditions. 

Post-traumatic stress disorder (PTSD) – A mental health condition that can affect anyone. It can develop after a single traumatic episode or by repeated trauma such as abuse or bullying. Some research suggests that autistic people or those with other neurodivergent conditions are also more prone to this. Especially if that were not diagnosed in later life. 

Complex post-traumatic stress disorder (cPTSD) – This is diagnosed when a person’s reactions to traumatic events extend beyond the definition of PTSD. The ICD-11 (International Classification of Diseases, 11th edition) created a new diagnosis of Complex PTSD. It consists of the same core symptoms of PTSD, but has three additional groups of symptoms: 

Eating disorders such as anorexia nervosa 

Burnout and workplace burnout

Autistic burnout A state of emotional, physical, and mental exhaustion caused by excessive and prolonged stress. It is similar to workplace burnout but happens with a higher frequency and as a result of all aspects of daily life, not just work. Mental exhaustion and sensory overload build up, resulting in an intense experience of complete physical, mental and emotional exhaustion that goes beyond fatigue. It causes dramatic increases in distress, increased meltdowns and shutdowns, physical pain, the inability to process any more information and loss of skills and abilities. 

ADHD burnout – Heavy fatigue, needing distance from work and / or people, feeling of performing less well, insecurity about one’s own capacities and depressed and/or emotional moods. (From the article below.) 

Bowel & bladder 

Nocturnal enuresis (bed wetting) – Common in autistic children. 

Irritable bowel syndrome (IBS) – A collection of various symptoms such as diarrhoea, constipation, wind and bloating. 

Constipation or diarrhoea – Whether part of IBS or not, quite common in autistic children and adults. Is sometimes due to difficulties around bodily awareness meaning that signals such as a full bladder or bowel are missed or misinterpreted. 

Neurological 

Epilepsy

Sleep disorders – Extremely common in both autism and ADHD

Specific learning disorders

Dysgraphia – One type of specific learning disorder and also considered a neurodevelopmental condition frequently seen with ADHD and autism. It causes difficulties with letter formation and word spacing in handwriting. It can also cause additional difficulties including written expression, translating ideas into language, organizing thoughts, use of grammar and punctuation.

Dyslexia – A second type of specific learning disorder and also considered a neurodevelopmental condition frequently seen with ADHD and autism. Can be confused with dysgraphia although they are also sometimes seen together. With dyslexia, it is often the spelling and sounding out of words when reading that are problematic but not usually the comprehension of language itself.

Dyscalculia – A third type of specific learning disorder and also considered a neurodevelopmental condition frequently seen with ADHD and autism. This affects the ability to understand, learn, and perform math and number-based operations.

Tourette Syndrome (TS)One type of neurological disorder characterised by severe or very frequent tics. Tics are involuntary, repetitive movements and vocalizations.

Functional Neurological Disorder (FND) – A medical condition in which there is a problem with the functioning of the nervous system and how the brain and body sends and/or receives signals, rather than a structural disease process such as multiple sclerosis or stroke. FND can encompass a wide variety of neurological symptoms, such as limb weakness or seizures. 

Hormonal 

Polycystic ovarian syndrome (PCOS) – In PCOS, the ovaries develop enlarged follicles around the eggs and can also cause irregular periods and an excess of testosterone which in turn can cause too much facial or body hair. Other symptoms may include acne, fatigue, low sex drive, weight gain, insulin resistance and infertility. 

Beginning around the teenage years or early adulthood, autistic women and ADHD women appear to suffer from this condition more often than in the non-autistic population. 

Pre-menstrual syndrome (PMS) – The emotional and physical symptoms that some women get in the one or two weeks before their periods begin each month. Autistic women and women with ADHD are known to be more likely to suffer from both this and PMDD. Both can also affect the way ADHD medications work and increase the risk of autistic discomfort and meltdowns. 

Pre-menstrual dysphoric disorder (PMDD) – A very severe and debilitating form of PMS which impacts life, work and relationships dramatically. It can lead to mental health crises and suicidal thoughts. Autistic women and women with ADHD are known to be more likely to suffer from both PMS and PMDD. Both can also affect the way ADHD medications work and increase the risk of autistic discomfort and meltdowns.

Muscles and joints 

Hypermobile joints – Autistic people are more likely to have hypermobile joints (‘be double jointed’) than the general population. This isn’t a cause for concern, but if there is widespread joint problems and pain, it may be worth looking into. 

Connective tissue diseases such as hypermobile Ehlers-Danlos Syndrome – These are rare connective tissue disorders. Hypermobile Ehlers-Danlos syndrome is one type which involves widespread joint hypermobility plus many other specific symptoms. Although rare, it has long been suspected as being more common within the autistic community than in the general population and this was recently confirmed. 

Poor muscle tone – Although not a disease or condition, it is more common in autistic people. 

Co-ordination difficulties – General co-ordination difficulties are more common with neurodevelopmental conditions, as is Dyspraxia (developmental co-ordination disorder). 

Dyspraxia – The preferred term for this is now developmental co-ordination disorder. This is because ‘dyspraxia’ can mean different things in adults, when it is caused by a stroke or head injury for example. It is a neurological developmental condition, which affects motor skills and co-ordination. Although it can impact learning, it is not a learning disorder.

Intellectual 

Learning disability (UK) – also known as intellectual disability in the US: A lower than average IQ and a lack of skills needed for daily living. A learning disability (LD) can vary in its severity and can be mild, moderate (MLD), or severe (SLD). 

Down syndrome – There has been some limited research which suggests that people with Down syndrome are more likely to be autistic than the general population. 

Learning 

Learning difficulties (UK) also known as learning disabilities in the US. A weakness in certain academic skills, usually maths, reading or writing. 

Specific learning differences / disorders / difficulties (SpLD) – An umbrella term for the neurodevelopmental conditions dyslexia, dyspraxia, dyscalculia, dysgraphia and ADHD. 

Profound & multiple learning difficulties (PMLD) – When there are several learning disabilities, the term profound and multiple learning difficulties is used. 

Language 

Information about a wide range of Speech Language and Communication Needs (SLCNs) 

Developmental language disorder – Identified when a child has problems with language development that continues into school age and beyond. The language problems have a significant impact on everyday social interactions or educational progress, and occur in the absence of autism, an intellectual disability or a known biomedical condition. The most obvious problems are difficulties in using words and sentences to express meanings, but for many children, understanding of language (receptive language) is also a challenge but may not be evident unless the child is given a formal assessment. 

Nonverbal learning disorder  People with this condition are not non-verbal (non-speaking). They are very much able to talk and talk well. The nonverbal means that they are poor at deciphering non-verbal language such as body language, facial expressions and tone of voice. Other difficulties include poor visual, spatial, and organisational skills and poor motor performance. 

Considered to be as common as dyslexia but often misdiagnosed or confused with ADHD. As the treatment for the two conditions is very different it is important to get the diagnosis right. 

Language processing disorder (LPD) – Difficulties with communicating through spoken language. This affects a person’s ability to understand what others are saying, which is called receptive language disorder. It can also make it very difficult to translate the simplest of thoughts into words and this is called expressive language disorder. It is also possible to suffer from a combination of both. 

Other 

Pathological demand avoidance (PDA) – Considered to be a particular profile of some on the autism spectrum, whose main characteristic is to avoid everyday demands and expectations to an extreme extent. 

Oppositional defiance disorder (ODD)A type of behaviour disorder. Children with ODD are uncooperative, defiant, and hostile toward peers, parents, teachers, and other authority figures. 

Speech, language and communication needs (SLCN) – This is an umbrella term used to describe difficulties across one or more aspects of communication. For example, conditions such as aphasia and dysarthria (difficulty controlling the muscles used in speech) stammering, difficulty pronouncing speech sounds, hoarseness and loss of voice, difficulties with the flow or tone of speech, language comprehension and difficulty using words and sentences. Some SLCN are short term and can be addressed through effective early intervention while others remain with a person throughout their childhood and adult life. 

Gifted and twice exceptional (2e) – Gifted refers to students with intellectual gifts or talents that give them the capability to perform at higher levels compared to others of the same age, experience, and environment in one or more areas. Because of this the student may need modifications to their educational environment in order to reach their potential. 

Twice exceptional (2e) is a term given to students who are considered gifted and who also have one or more learning disabilities, such as dyslexia, ADHD or ASD.

Fibromyalgia syndrome – A chronic pain disorder with multiple other debilitating symptoms such as chronic fatigue, joint problems, disordered sleep and brain fog. Studies as far back as the 1990s have linked ADHD and fibromyalgia. There seems to be a higher incidence in people with ADHD than in the general population. ADHD medication can sometimes help with the symptoms. 

ME/CFS / Post Viral Syndromes – Like for the close relative, fibromyalgia syndrome, there seems to be a greater chance of autistic people and ADHDers suffering from these conditions. It is possible that growing up with autism or ADHD in a neurotypical world is a huge stressor to the body, which in turn is very detrimental to the immune system, inflammation and many other things. Or that the common co-occurrence of mental health conditions and trauma has a lot to do with this also. Chronic stress and anxiety go hand in hand with many neurodivergent conditions and chronic stress damages the immune system. Neuroimmunology is a relatively new field which is shedding light on many of these connections. Either way, it doesn’t seem surprising that these conditions can plague us more than neurotypical people. 

Mast Cell Activation Syndrome and Histamine Intolerance – This is a complicated neuroinflammatory condition. It is linked loosely to many, many conditions because of its ubiquitous nature. It can also cause an endless array of symptoms including brain inflammation. Interestingly, it is also very common in certain rare connective tissue diseases such as hypermobile Ehlers-Danlos syndrome and the pain disorder, fibromyalgia syndrome. And lots of other things – all of which have links to autism in varying degrees. It’s one to watch perhaps. 

Rejection Sensitive Dysphoria – Becoming more widely known, particularly with ADHD. It is extreme emotional sensitivity and pain triggered by the perception that a person has been rejected or criticized by important people in their life. It may also be triggered by a sense of falling short—failing to meet their own high standards or others’ expectations. 

Sluggish Cognitive Tempo (SCT) – This is an attention disorder associated with the following symptoms that resemble signs of inattentive ADHD such as excessive day dreaming, behaving lethargically, poor memory retrieval, trouble staying alert in boring situations, slow processing of information, and acting withdrawn. It can occur alone or with ADHD.

More information about autism at www.autistic-ness.com