Other Common Intellectual, Developmental, and Learning Disabilities
The world of intellectual, developmental, and learning disabilities is vast. This training will provide a brief introduction to a variety of other common disabilities, general health issues common for individuals with intellectual and developmental disabilities, and explore a few issues that occur around the time of birth.
The Arc of Bartholomew County
The Arc of Bartholomew County is a nonprofit organization aiming to be the resource of choice for individuals with intellectual or developmental disabilities and their families.
The organization was established in 1956 and continues to serve the community.
The training you're currently exploring was developed with the support of a Heritage Fund grant. The grant's goal was to expand online services and build resilience during the pandemic.
Training Introduction
This training introduces the other common intellectual, developmental, and learning disabilities.
It's designed to be completed in one sitting, but there are no time limits. This is a guided learning experience. We expect this training to give you a deeper understanding of the topic both technically and culturally.
Learning & Developmental Disorders
Learning disorders are a group of neurological conditions classified by an increased difficulty to use certain types of learning skills such as reading or writing. A person with a learning disorder doesn't necessarily have lower motivation or intelligence. In fact, it isn't uncommon to find high achievers with learning disorders.
Learning disorders are always present; one doesn't grow out of a learning disability. If recognized and understood, accommodations can be developed which mitigate the issues in a fair way. For example, someone with dysgraphia, a writing disorder, may prefer to take examinations orally rather than in written form.
Included in this section are related developmental disorders that aren't considered learning disorders but would affect classroom learning (e.g., dyspraxia).
Reading Disorders: Dyslexia, Alexia, and Hyperlexia
Writing Disorders: Written Expression Disorder, Dysgraphia and Agraphia
Math Disorders: Dyscalculia, Acalculia, and Hypercalculia
Coordination Disorders: Developmental Coordination Disorder, Dyspraxia and Apraxia
Language Disorders: Language Processing Disorder, Dysphasia, and Aphasia
Hearing Disorder: Auditory Processing Disorder
Visual Disorder: Visual Processing Disorder and Visual Agnosia
Nonverbal learning disabilities
Reading Disorders: Dyslexia, Alexia, and Hyperlexia
According to the Yale Center for Dyslexia, dyslexia affects 1 in 5 people. It's the most common learning disability, accounting for up to 90 percent of learning disabilities people have. Dyslexia impacts an individual's ability to read and understand written words and symbols.
The condition is neurological in nature, primarily affecting parts of the brain that are responsible for language processing. Dyslexia isn't directly caused by or related to vision issues. Common signs of dyslexia, outside of reading issues, are difficulty spelling and being able to quickly produce the name of objects. Yale's Center for Dyslexia has more information about this subject: https://www.dyslexia.yale.edu/dyslexia/dyslexia-faq/
Alexia is a reading disorder acquired later in life, often due to a brain injury or stroke. Depending on the nature of the injury and the age of the individual, Alexia may affect different aspects of reading ability.
A final reading disorder, hyperlexia, can (imperfectly) be considered an opposite of dyslexia. Hyperlexic individuals often have the ability to read at an early age and tend to have better reading abilities than their peers.
Research is ongoing in this area, but it's hypothesized that there are hyperlexia subtypes. One of these subtypes seems to be comorbid with Autism Spectrum Disorder while another is often misdiagnosed as Autism.
Writing Disorders: Written Expression Disorder, Dysgraphia and Agraphia
Written expression disorder is a learning disability that relates to writing. A person with this disorder has difficulty converting thoughts to writing. This can take the form of disorganization or grammatical mistakes. Written expression disorder is deals specifically with mental processes and does not refer to issues with the physical act of writing.
Individuals with other writing difficulties may have a condition known as dysgraphia. Like dyslexia, the problems a person with dysgraphia faces do not result from a lack of intelligence or effort. Dysgraphia usually exists with another diagnosis (e.g., dyslexia). Agraphia is the acquired version of dysgraphia, due to brain injury or accident at a later point in life.
Individuals with dysgraphia, may experience writing issues due to problems in one or more of the areas of the brain related to this complex task. In order to write, a person must convert an idea into a physical action driven by fine motor skills.
Dysgraphia subtypes are classifications of where the issue exists. Motor dysgraphia, for example, is dysgraphia primarily related with the physical act of writing. Spatial dysgraphia corresponds to a difficulty in understanding space, causing illegibility of writing in some instances due to inappropriate spacing between letters and words.
Math Disorders: Dyscalculia, Acalculia, and Hypercalculia
The learning disorder associated with a difficulty in mathematics is called dyscalculia. When dyscalculia is acquired later in life the person is said to have acalculia.
There are several symptoms of dyscalculia and an individual likely has more than one. One symptom is the inability to connect the symbol for a number with the number written in word form. Conceptual understanding of mathematics and being unable to apply those concepts is another symptom of dyscalculia.
Higher level skills, which benefit from skills in mathematics, can be affected by dyscalculia. For example, the inability to budget and manage finances might be evidence that a person has dyscalculia.
Just like hyperlexia's relation to dyslexia, dyscalculia corresponding condition is known as hypercalculia. Hypercalculia is an advanced ability to perfom mathematical calculations.
Abilities, like hypercalculia, which exceed the abilities of neurotypical individuals are more likely to be overlooked when other diagnoses are present. The actual values vary, but some report over 10% of individuals with Autism have hypercalculia.
Coordination Disorders: Developmental Coordination Disorder, Dyspraxia and Apraxia
Developmental Coordination Disorder (DCD) is a recognized neurodevelopmental disorder related to difficulty with physical movements. DCD affects an individual's fine and gross motor skills.
Fine motor skills refer to precise movements like writing or using a computer. While gross motor skills are bigger movements, like walking, running, and jumping.
The term dyspraxia is an informal term related to motor coordination issues. Unlike other disorders mentioned in this section, apraxia is not the acquired version of dyspraxia. Both dyspraxia and apraxia may be acquired.
Dyspraxia refers to a milder form of the disorder, while apraxia is a complete inability to perform tasks which require motor coordination.
Individuals with dyspraxia often have other learning disabilities as well, like dyslexia and dyscalculia. It's also fairly common for these individuals to have Attention Deficit Hyperactivity Disorder (ADHD). Addressing each condition, for an individual with multiple learning disorders, can improve other mental health conditions as well.
Language Disorders: Specific Language Impairment, Language Processing Disorder, Aphasia, and Einstein Syndrome
Specific Language Impairment (SLI) is a developmental disorder where an individual has communication issues related to the use of language. Specifically, SLIs are a subtype of communication disorders for people who don't have hearing loss or intellectual disabilities.
While an SLI is not a learning disorder itself, children with SLIs are more likely to be diagnosed with a learning disorder than children without an SLI.
Language Processing Disorders (LPD) are related to an SLI. LPD refers to both sides of language processing: understanding someone else's communication and being able to convert internal thoughts into language.
When a person has difficulty processing language that's coming from someone else, they would be considered to have a receptive LPD. If the issue occurs when attempting communicate their internal thoughts, then that's considered an expressive LPD.
Aphasia is the acquired form of a language disorder. A person who experiences brain damage in the specific area of the brain related to language processing may develop a language disorder.
Dysphasia is a related, but less commonly used, term for language disorders related to brain injury.
Einstein Syndrome (ES) is a type of language delay identified by Thomas Sowell. The informal condition is named for Albert Einstein who spoke later in childhood.
Children who excel in other areas and begin speaking later in life may be candidates for ES. ES is not a formal diagnosis, but might account for a small minority of children who appear to have language disorders.
Hearing Disorder: Auditory Processing Disorder
Auditory processing disorder (APD) is a condition related to problems that occurs between hearing a sound and processing that sound in the brain. Like other learning and developmental disorders mentioned, this is a specific condition unrelated to hearing loss or intellectual disabilities, though, those individuals may have APD as well.
Paradoxically, accommodations for individuals with hearing loss may also benefit those with APD. For children in a classroom setting, assistive devices like a remote microphone system might be used. This tool helps reduce background noise to increase the teacher's speech clarity.
Audiologists and speech therapists can help individuals with APD understand the diagnosis and find strategies that help reduce the impact of APD. Like other developmental disorders, once identified, a person is able to understand issues faced earlier in life and helps them move forward more effectively.
Getting professional help for APD may also reduce the impact of co-occurring issues that resulted from not knowing about a diagnosis or thinking that the issues were a result of negative personal traits (e.g., laziness).
Visual Disorder: Visual Processing Disorder and Visual Agnosia
Visual Processing Disorders (VPD) affect a person's ability to process different types of visual information. Research suggests that visual processing combines many different modalities, or types, of visual information. Using an object for illustration, one visual modality would be its color while another would be its position relative to everything else in the scene.
Different types of VPD exist, with varying degrees of complexity to understand and diagnose. One type, visual agnosia, describes a condition where an individual is unable to visually process a particular object. A person with visual agnosia may see an object but be unable to describe it's uses.
This occurs in people who have typical vision (they're not blind or have low vision) and intelligence, so issues in those areas are ruled out. Further, in a surprising illustration of the complexity of the human nervous system, the person has the ability to describe the object's use when they touch it.
Visual agnosia is further split into different subtypes based on unique ways visual processing is disrupted. Transformational agnosia, for example, refers to processing issues when objects are viewed in different ways (e.g., upside down).
As science advances the understanding of the brain and its complex processing capabilities, it's clear that more nuanced understanding of how humans process visual information will be uncovered and, with that knowledge, additional avenues for identifying subtle disorders in our perception of reality.
Nonverbal Learning Disabilities
The final learning disorder in this section is one of the most abstract and controversial. As the name suggests, a nonverbal learning disability (NVLD) occurs in individuals who have trouble with nonverbal abilities like motor coordination, understanding social situations, and processing visual-spatial information.
Motor coordination may display as clumsiness. Issues with social situation often stem from difficulties picking up and deciphering social cues.
Visual-spatial information processing refers to the understanding visual information. A person who has trouble with visual-spatial processing would have difficulty packing a vehicle for a move.
Individuals with NVLD tend to have many overlapping symptoms to those with Autism Spectrum Disorders.
For this and similar reasons, NVLD is not currently recognized in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). Further research is required to understand NVLD and how it fits in the increasingly complex psychosocial environment.
Psychiatric & Behavioral Disorders
Like learning disabilities, psychiatric disorders are often hidden from view and, unfortunately, complicated in diagnosis and treatment. While seeking assistance for mental illness has become less taboo, many avoid seeking help for fear of being stigmatized or simply a lack of understanding.
In a similar vein, behavioral disorders, like oppositional defiant disorder, may not be recognized initially. Treatment, in counseling and/or medication, can lead to quality of life improvements in many cases.
Attention Deficit Hyperactivity Disorders (ADHD)
Behavioral Disorders: Oppositional Defiant Disorder (ODD) and Conduct Disorders
Anxiety Disorders: Generalized Anxiety Disorder, Phobias, and Others
Depressive Disorders: Major and Persistent Depressive Disorder, situational depressive disorders, and Bipolar Disorder
Attention Deficit Hyperactivity Disorder (ADHD)
Attention Deficit Hyperactivity Disorder (ADHD) affects one's ability to control his or her attention. ADHD was previously known as Attention Deficit Disorder (ADD), but this designation is no longer used.
There are currently three recognized subtypes of ADHD (according to the Mayo Clinic): predominately inattentive (ADHD-PI), predominantly hyperactive-impulsive (ADHD-PH), and a combination of the previous two Combined (ADHD-C).
Studies suggest that ADHD may be caused by both genetic (i.e., it can be passed between generations) and environmental factors, like lead exposure.
Due to the lack of a diagnostic test, healthcare practitioners make an ADHD diagnosis based on comparison to specific criteria. ADHD symptoms can vary in severity between different individuals and ADHD subtypes.
ADHD affects both adults and children, though the symptoms differ here as well. For example, an adult with ADHD may have developed coping strategies which may cause them to go undiagnosed.
Individuals who have ADHD may experience hyperfocus, the ability to maintain focus on a single subject for a long period of time. This can adversely affect social development and relationships if left unregulated. For example, a child who becomes hyperfocused on a video game could conceivably spend an entire weekend alone.
Behavioral Disorders: Oppositional Defiant Disorder and Conduct Disorder
Oppositional defiant disorder (ODD) is a behavioral disorder characterized by rebellious actions. The majority of children will defy parental authority on occasion. The difference between a child who has ODD is the severity and frequency of these occurrences.
As defined in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), ODD presents as recurrent behavior in three categories: angry/irritable mood, argumentative/defiant behavior, and/or vindictiveness.
ODD severity is defined by contexts in which the defiant behavior occurs. A child with mild ODD would exhibit oppositional behavior in one setting, moderate in two settings, and severe in three or more settings.
Children under five years old may have ODD if they exhibit these behaviors most days over a period of six months, while children five years or older would exhibit these signs once a week for six months.
Of course, there are many complicating factors when making an ODD diagnosis. A child who experiences abuse, neglect, or other traumas are more likely to have ODD.
Conduct disorder is similar to ODD, but has more dangerous symptoms. The DSM-5 categorizes conduct disorder into the following: aggression to people or animals, desctruction of property, deceitfulness or theft, and serious violations of rules (e.g., truancy).
Both ODD and conduct disorder are commonly comorbid (appearing with) individuals who have Attention Deficit Hyperactivity Disorder (ADHD).
Anxiety Disorders: Generalized Anxiety Disorder, Phobias, and Others
Anxiety disorders refer to feelings of excessive fear or worry about a potential future situation.
To be classified as an anxiety disorder, the feelings must be more severe than what one would typically expect from life stresses and must significantly impact a person's life. There are a variety of unique anxiety disorders each with their own symptoms and challenges.
A person with generalized anxiety disorder would experience anxiety in daily life, often in situations that are routine. People who experience anxiety when leaving the presence of people they care about might have separation anxiety disorder.
Social anxiety disorder, sometimes referred to as social phobia, would cause a person to avoid social situations due to fears about how the person would relate to others. Panic disorder causes a person to experience a rapid onset of anxiety (a panic attack).
Another group of anxiety disorders include fears about specific situations or places. These phobias are more specific than would be experienced by a person with generalized anxiety disorder.
Agoraphobia, commonly associated with individuals who never leave their homes, causes a person to increasingly avoid situations where they may feel trapped (like public places). There are several more anxiety disorders (e.g. selective mutism) and specific phobias that a person may experience.
With therapy and medication it's possible to treat anxiety disorders. Unfortunately, many people don't seek help for anxiety disorders and are unaware that effective treatment exists.
Depressive Disorders: Major and Persistent Depressive Disorder, situational depressive disorders, and Bipolar Disorder
One common symptom of depression is severe sadness or a feeling of emptiness that persists nearly every day for two weeks or longer. A person who experiences one of several symptoms of depression over this time frame may have a form of depression called major depressive disorder.
Despite internal feelings a person with depression is experiencing, it may not be obvious to outsiders that a person is depressed. In fact, depression can appear differently between people and may even be different for people at different points in their lives.
If the depressive symptoms last for two years or longer, the person may be diagnosed with persistent depressive disorder (or dysthymia).
Some types of depressive disorders are situational or occur near an event or timeframe. Postpartum depression, for example, is a depressive disorder mothers experience after giving birth. Depressive symptoms may also occur during certain seasons, like the summer or winter, in a condition known as seasonal affective disorder.
Bipolar disorder has similar symptoms to depressive disorders, but is not directly classified as a depressive disorder. One major difference is that bipolar disorder includes an opposing state known mania. A person experiencing a manic episode might exhibit high energy, euphoria, be more expressive, and may be irritable.
Depression, in each form, is complicated. Since each person's depression is somewhat unique, treatment may take the form of therapy and/or medication. With help, though, it's possible to find the right combination that manages or alleviates depression.
Other Health Issues
Comorbidities is the name for multiple diseases or disorders occurring at the same time. The health issues described in this section frequently appear as comorbidities in individuals with intellectual and developmental disabilities (I/DDs).
Often the cost and effort to treat indivduals with I/DDs is significantly larger, than it otherwise would be, due to these comorbidities.
Heart Disease: Coronary Artery Disease and Congential Heart Defects
Visual Impairments: Refractive Error and Other Eye Diseases
Epilepsy & Seizures
Dementia: Alzheimer's disease & Other types of dementia
Heart Disease: Coronary Artery Disease and Congential Heart Defects
The heart is a complicated organ composed of four chambers and a special type of muscle tissue (called myocardium). It's a central part of the cardiovascular system which transports oxygen, nutrients, and hormones throughout the body.
Heart disease, specifically coronary artery disease, is the leading cause of the death in the United States. There are a number of types of heart disease some caused by lifestyle while others are hereditary. Factors that contribute or increase the risk of developing heart disease include diabetes, obesity, poor diet, and lack of exercise.
A congential heart defect (CHD) is a type of heart disease that's present at birth. CHDs are common in babies with Down syndrome and, if severe, require one or more surgeries to repair the issue. Some CHDs resolve over time or, more generally, don't cause future issues.
Visual Impairments: Refractive Error and Other Eye Diseases
Individuals with visual impairments have difficulty with sight, ranging from complete loss (blindness) to milder forms which may go undetected.
The most common cause of visual impairment are refractive errors: near-sightedness (myopia), far-sightedness (hyperopia), asytgmatism (errors in light processing), and presbyopia (refractive errors due to age). Eyeglasses and contact lenses are usually prescribed to treat refractive errors.
Cataracts (clouding of the lens) are the second most common cause of visual impairments. Lens replacement through cataract surgery, if appropriate, is an effective treatment for cataracts.
Strabismus, a visual impairment often found in individuals with Down syndrome, occurs when eyes are misaligned.
Visual impairments which cannot be cured may be mitigated through other means. Braille, a system of writing that uses raised bumps to represent letters, allows individuals with visual impairment to read books, navigate the world, and even use computers.
Epilepsy & Seizures
Epilepsy is neurological disorder characterized by seizures. A seizure is simply abnormal brain activity for a period of time (usually short). There are several types of seizures, some involve dramatic body movements (tonic-clonic seizures) while others are more subtle and may look like a person is daydreaming (absence seizures).
Seizures might affect one side of the brain, these are called focal or partial seizures. Generalized seizures, are seizures that affect both sides of the brain.
Epilepsy can be caused by a variety of reasons from strokes, brain tumors and infections, and other brain injuries. Individuals with genetic disorders, like Down syndrome, or those with neurological diseases (e.g., Dementia), may also have epilepsy. The majority of individuals (two-thirds) don't have an identifiable cause for their epilepsy.
Many treatment options exist for epilepsy. Medication, surgery, electrical nerve stimulation, or diet changes may be included in a prescribed treatment plan.
Dementia: Alzheimer's disease & Other types of dementia
Dementia refers to a group of neurological disorders where an individual's "memory, language, problem-solving and other thinking abilities" are lost to a degree that impairs daily function. Though dementia is more common in elderly adults, people under 65 years old may experience a form of early-onset dementia.
The majority of individuals who have dementia have a form called Alzheimer's disease. Alzheimer's disease is a general form of dementia and, while Alzheimer's disease doesn't have a definitive cause, it's believed that damage to nerve cells in the brain, caused by the buildup of proteins, may contribute.
A person with Alzheimer's disease will experience worsening symptoms which, with current medical technology, will lead to death in a number of years.
In addition to Alzheimer's disease, there are several other types of dementia. Vascular dementia, caused by bleeding and/or blocked blood vessels in the brain. Parkinson's disease and lewy body dementia are two forms of dementia with a connection to another protein buildup forming what are known as lewy bodies.
A form of dementia, frontotemporal dementia, affects the "frontal and temporal lobes of the brain." Another progressive disorder affecting the brain is the hereditary disorder known as Huntington's disease. Finally, a person may have a combination of several different types of dementia which is called mixed dementia.
There is currently no cure for dementia, but treatment can slow the progression of some forms of dementia.
Issues at Birth
The three issues in this section are typically identified at birth. Each is simillar in terms of commonality, but they're each different in terms of likelihood the baby will experience future issues.
The first, low birthweight, is relatively common and may not be caused by an underlying condition. Hypotonia is less common, but is more likely to be caused by another disorder. Finally, Fetal Alcohol Spectrum Disorders (FASD) are quite common and have a directly identifiable cause: alcohol consumption during pregnancy.
Low birthweight or Underweight
Hypotonia
Fetal Alcohol Spectrum Disorders (FASD)
Low birthweight or Underweight
A baby's birthweight is a strong health indicator. When a baby is born underweight (weighing less than 2,500 grams or 5.5 pounds), they are more likely to be affected by a number of short-term health issues like breathing problems, an increased susceptibility of infections, and jaundice.
Underweight babies are also more likely to have intellectual and developmental disabilities, diabetes, heart disease, high blood pressure, metabolic syndrome, and obesity.
Underweight babies are more common in preterm births, or births that occur earlier than 37 weeks after conception. Early term births are babies born in the 37th and 38th weeks, while full-term encompasses the 39th week, the 40th week, and six days after the 40th week.
With multiple births (e.g., twins), the likelihood that each baby is underweight increases as well.
Pregnant individuals with certain risk factors are more likely to give birth to underweight babies. These risk factors include having a chronic health condition (e.g., diabetes), having certain types of infections (e.g., chickenpox), not gaining enough weight during pregnancy, and others.
Lifestyle risk factors, like using drugs and alcohol, being exposed to environmental pollution, having a low socioeconomic status, or being the victim of domestic violence, each increase the chance a baby will be born underweight.
Hypotonia
Hypotonia is a condition defined as having low muscle tone. The term tone in this context refers to the ability of the muscles to fully contract or flex. This condition does not refer to muscles being weaker (or stronger) than what would be typically expected.
The cause of hyptonia could be a number of different disorders (e.g., Down syndrome, cerebral palsy) or it could be benign (meaning it won't cause further issues).
Babies born prematurely are also more likely to have hypotonia. A baby with hypotonia may resemble a rag doll and have difficulty controlling body movements.
As the child ages, he or she may experience developmental delays. Speech, for example, could be affected by hypotonia due to the increased difficulty of using vocal muscles.
Treatment for hypotonia varies depending on the cause. For premature babies, without other underlying issues, hypotonia typically resolves itself.
Occupational and/or physical therapy, may be required if another condition is present. For certain individuals, hypotonia may never be cured, though the condition can improve over time.
Fetal Alcohol Spectrum Disorders (FASD)
Fetal alcohol spectrum disorders (FASD) occur when a person consumes alcohol while pregnant. There is no known safe amount of alcohol to drink while pregnant, including the weeks after conception when detection isn't typically possible.
FASD covers several diagnoses depending on the severity and bodily systems affected. Fetal Alcohol Syndrome (FAS) affects the central nervous system and often causes facial deformities. Individuals with Alcohol-Related Neurodevelopmental Disorder (ARND) may have intellectual disabilities and issues with learning.
Alcohol-Related Birth Defects (ARBD) involve issues with organs such as the kidneys, heart, and bones. Neurobehavioral Disorder Associated with Prenatal Alcohol Exposure (ND-PAE) is a more complicated FASD, causing thinking or memory issues, behavioral problems, and difficulties with daily life.
Abstaining from alcohol during pregnancy can prevent FASD. It's important to understand that substance use during pregnancy is often accompanied by broader social and emotional issues and often various traumas.
While there's no cure for FASD, eariy intervention and additional support can improve the lives of those affected by FASD.
