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What is
Intellectual Disability

What is Intellectual Disability


Intellectual disability is a neurodevelopmental disorder characterized by impairment in the child's cognitive and intellectual functioning. It was earlier referred to as Mental Retardation, however, that connotation has stopped being used. The child usually has difficulty in learning and grasping concepts and information, as compared to children of his/her age. They also have difficulty in adaptive and social functioning in everyday life.

The main difficulty they face is coping with a conventional, or a regular system of education. Due to this reason, they are put in a special school and taught basic concepts and activities of daily living. An IQ score below 70 indicates towards a diagnosis of Intellectual disability. Children with Down Syndrome or Fragile X syndrome also have Intellectual disability. A diagnosis of Global Developmental delay is given for children under the age of 5 years when the level of severity cannot be assessed in early childhood.

What are the types of Intellectual Disability?

There are 4 levels of Intellectual disability based on the IQ score as well as their level of adaptive functioning: mild, moderate, severe and profound.

Level of Intellectual disability

IQ range

Degree of functioning


50 - 55 to 70

  • Can fully take care of basic needs - eating, brushing, bathing, dressing and toileting.

  • Has difficulty in reading, writing and comprehending.

  • Are very good candidates to be trained.

  • Can be taught some easy, repetitive work, improving chances of employment - jobs such as Xeroxing, working as a Helper, Housekeeping, Cooking, Back office, Machine operator, Loading-unloading, Arranging groceries etc.

  • Can also travel by themselves in the city if taught to.

  • Face difficulty in taking up responsibilities of marriage or parenting.

  • Still need supervision of the elders.

  • Can communicate better and express their basic needs.

  • May or may not understand simple, basic calculations.

  • Can use a calculator if taught and can identify numbers.

  • Can be encouraged to make use of their strength/interest - such as cooking, drawing, dancing, sports etc.


35 - 40 to 50 - 55

  • Is slower in understanding and grasping.

  • Always needs parental assistance for basic activities - eating, dressing, bathing and toileting.

  • Cannot live an independent life.

  • Has difficulty in communicating.

  • Finds difficulty in taking up a job.


20 - 25 to 35 - 40

  • Severe impairment of intellectual functions.

  • Cannot understand their own basic needs.

  • May or may not recognize family members as their own

  • Needs assistance to carry out all basic activities - eating, bathing, brushing and toileting.

  • Significant behavioral issues - such as physical abuse.

  • Significant difficulty in speech - can hardly communicate. Will only make sound to indicate for food or water.


Below 20 or 25

  • Completely dependent on family for all the activities of daily living.

What causes Intellectual Disability?

In about one-third of the cases of Intellectual disability, the cause is unknown. However, there are certain known risk factors or reasons that can lead to Intellectual disability in the child.

  • Infection - Any infection at the time of birth or during pregnancy. For example, improper development of the fetus, not having enough oxygen reaching the brain, alcohol consumption during pregnancy etc.

  • Genetic conditions - Genetic conditions such as Down's Syndrome, Williams Syndrome, Fragile X Syndrome etc.

  • Metabolic - Such as hyperbilirubinemia, very high bilirubin levels in babies.

  • Nutritional - Malnutrition being one of the major causes leading to intellectual disability.

  • Environmental factors - Such as lead or mercury poisoning.

  • Iodine deficiency. - Low and prolonged levels of iodine in the child at the age of development can cause Intellectual Disability

What are the early signs and symptoms associated with Intellectual Disability?

The symptoms exhibited by children or patients with Intellectual disability differ according to the level of their disability - mild, moderate or severe.

A child with Mild Intellectual disability will have:

  • Poor attention and concentration span.

  • Difficulty in following multiple commands at one time.

  • Mild impairment in memory, learning and grasping.

  • Low sitting tolerance, hyperactivity in some cases.

  • Extremely withdrawn behavior or being inactive throughout the day.

  • Difficulty making friends and communicating clearly with other children or people.

  • Mild impairment in awareness about surroundings and poor judgment.

A child with Moderate Intellectual disability will have:

  • Poor command following - difficulty following one step basic command.

  • Poor memory, learning and grasping.

  • Presence of hyperactivity, poor sitting tolerance and aggressive behavior at times.

  • Fully dependent for basic activities of daily living - eating, bathing, dressing and toileting.

  • Presence of irrelevant laughter or crying at times.

  • Difficulty in communication and expressing their basic needs.

  • Presence of behavioral issues at times -such as stubbornness and physically abusive behavior.

What are the tests available to detect Intellectual Disability?

In order to plan a treatment for a child or adult with Intellectual disability, the first and foremost thing is to derive his/her Intellectual Quotient(IQ).

The IQ test mainly used is:

  • The Wechsler Intelligence Scale(WISC) for Children and the Wechsler Adult Intelligence Scale(WAIS).

  • If there is a language barrier, then the Wechsler Adult Performance Intelligence Scale (WAPIS) is used for such a population.

  • We also use the Malin's Intelligence Scale for Indian Children which is an Indian adaptation of the WISC. It is used for children in the age range of 6 to 15 years only.

  • The Binet Kamat Test is also used to assess the IQ of a child from the age of 3 years.

  • If the child is unable to perform in the objective IQ test, then a Social Quotient (SQ) is derived based on the questions asked to parents. It is the Vineland Social Maturity Scale (VSMS).

What are the treatment options available for Intellectual disability?

Based on the performance of the child on the above mentioned tests, the detailed clinical history and his/her interests, the child's strengths and weaknesses can be analyzed. This will help to plan the treatment ahead. His strengths can be utilized to develop his potential to the best of his ability and weaknesses can be worked upon. A supervised rehabilitation plan plays a big role in facilitating independence and the ability to lead fulfilling lives for these children. Some of the treatment options available are as follows:

  • Psycho-education

    The first and foremost thing is to educate parents about their child's strengths and weaknesses. This helps parents to know which areas to work in, and encourage the child to pursue it further.



  • Behavior therapy

    Behavior modification strategies can be taught to parents to reduce the child's inappropriate behaviors and replace it with desirable behavior through positive and negative reinforcement.

    Behavior therapy


  • Pharmacotherapy

    Consulting a Psychiatrist to deal with the behavior issues of the child that are not manageable by psychotherapy alone. He/she can be started on medications to reduce hyperactivity and aggressive behavior. Only when these behaviors go down, can the child can sit in one place for long and pay attention to any task.



  • Special School

    It is extremely important to send these children to school, especially, children with a mild to moderate level of intellectual disability. Schooling helps them learn read and write and also socialize, which helps them in making new friends. They meet children with similar kind of problems and can support each other, and not feel different. The teachers can encourage them work on their strengths and potential, which can enable them to lead independent lives.

    Special School


Scope of Cell Therapy for Intellectual Disability?

The treatment options for Intellectual Disability that are currently available help the patients in managing their academics and day to day living to some extent, but they do not repair the underlying cause of delayed neurodevelopment. Therefore developing a standard therapeutic approach is a need of the hour. Scientists and researchers worldwide are now considering cell therapy as a potential treatment option for patients suffering from Intellectual Disability.

This is a relatively new form of treatment available for Neurodevelopmental disorders. Cell therapy helps in reducing the problem behaviors of the child in the first place. For example, reducing hyperactivity, increasing his sitting tolerance, reducing aggressive and stubborn behavior which allows the child to cooperate. This in turn builds up his learning capacity and grasping power. His social interaction improves as well. He understands relationships better and develops a sense of self.

Stem cells obtained from various sources can be used for cell therapy. Our approach, at NeuroGen BSI makes use of autologous bone marrow derived mononuclear cells (BM MNCs) for transplantation. The transplanted stem cells have the ability to migrate to the area of the damaged tissue in the brain and home in those affected areas to help repair the damage. They release several trophic factors that decrease the effects of damage in those areas and also differentiate into several cell types of the nervous system such as oligodendrocytes, glial cells and other cells of the nervous system. The main mechanisms that help tissue repair and regeneration include:-

  • Prevention of cell death in neuronal population

  • Establishment of new blood vessels

  • Cell multiplication and integration

  • Establishment of new neuronal maps in the brain in order to learn new functions.

These mechanisms repair and regenerate the damaged tissue, restoring activity in the affected area, which translates into clinical improvements .This plays a great role in improving the overall quality of life. Also autologous BM MNCs do not show any adverse side effects and they do not face any immune rejection. Also, they are obtained from the same patient and thus are free of the ethical issues surrounding the use of stem cells.

NeuroGen's Outcome in Intellectual Disability

We have treated almost 450 patients, with Intellectual disability of various age groups and severities. We have seen tremendous improvement in most of our cases of Intellectual disability.

Intellectual Disability Graph

In case of Mild Intellectual disability, the child shows improved attention span and concentration, increased speed of processing, reduced hyperactivity and better sitting tolerance in school. They begin to show interest in studies, can learn faster and their memory improves. Performance in school improves and getting them to study becomes easier for the parent or the teacher. They become more active and responsible. If taught properly by a special teacher, the child can also learn basic mathematical calculations and the use of a calculator in daily life. They becomes more confident of their abilities and start venturing out as well. Their communication skills improve and They can make friends and socialize.

In case of Moderate/Severe Intellectual disability, wherein the child or adult is dependent for his/her basic ADL, the level of independence relatively increases. They are able to bathe themselves, get toilet trained or at least communicate their bathroom needs. This makes taking care of the child easier and improves quality of life.


Intellectual Disability Scans

Frequently asked questions

Q1) What is Intellectual disability/ Mental Retardation exactly?

Intellectual disability is basically an impairment in general mental ability that impacts everyday functioning in 3 major domains:

  • The conceptual domain - which includes skills in language, reading, writing, math, reasoning, knowledge, and memory.

  • The social domain - which refers to interpersonal communication skills, empathy, social judgment, the ability to make and retain friendships, and similar capacities.

  • The practical domain - which centers on self-management in areas such as personal care, job responsibilities, money management, recreation, and organizing school and work tasks."

Q2) How can the diagnosis be made?

A diagnosis is made based on the clinical evaluation and a standardized intellectual testing. An IQ score of 70 or below is still considered to make a diagnosis of Intellectual Disability. The diagnosis can also be made based on the child's clinical picture and adaptive functioning if the IQ test cannot be done.

Q3) When is the diagnosis made?

The diagnosis is made after infancy, when the child just begins school.

Q4) How early can parents seek early intervention when their baby is found to be developmentally delayed?

As soon as it is recognized that the young child is developmentally delayed in cognition and intellectual functioning in comparison to other normal children or siblings, prompt treatment and intervention will help the child to reach his/her optimal level of development.

Q5) What is the lifespan of a child with Intellectual Disability?

Intellectual disability by itself does not reduce a child's normal life span. A lot depends on the cause, severity of disability, associated medical problems and the level of care given.

Q6) Will I have another child like this?

Depending on the cause, there may be the possibility of another child being affected. Therefore, parents are advised to go for genetic counseling prior to planning for another child.

Q7) Are there possibilities of other disabilities along with Intellectual Disability?

Yes. The most common comorbid disabilities include autism, cerebral palsy, hyperactivity and epilepsy.

Q8) What is available in terms of treating or dealing with Intellectual Disability?

A child with Intellectual Disability needs specialized training, one-on-one attention, as well as specific therapists.

  • Special educators - who make programs specifically designed to address each individual child's special needs by modifying teaching methods and the child's enviro

  • Occupational therapists - who focus on teaching skills to make the child capable of carrying out his/her basic activities of daily living. The main goal here is to make the child independent and take care of themselves without any assistance.

  • Speech Therapist - It has been found that many children with Intellectual disability also have trouble articulating speech due to which it affects their communication skills and forming friendships. Speech therapists help and focus on language components which include manipulating sounds, using minimal units of meaning, sentence construction as well as social aspects of communication.

  • Psychologists - Psychologists play a crucial role in terms of assessment and classification of intellectual disability. Assessment includes carrying out a formal standardized intellectual testing (IQ test) on the child and counseling the parents accordingly. It is important for the parents to know the capacity or potential of their child and encouraging them accordingly, taking into consideration their strengths and weaknesses.

Q9) Are there different types or levels of Mental retardation?

Yes. There are different levels of Mental retardation which fall into mild, moderate, severe and profound.

  • Mild Mental retardation - Children with mild retardation can generally learn reading, writing, and math skills between the third- and sixth-grade levels. In adulthood, they may have jobs and live independently.

  • Moderate mental retardation - Children with moderate mental retardation may be able to learn some basic reading and writing but require supervision and monitoring in day to day living. They need assistance to carry out their basic activities of daily living.

  • Severe mental retardation - Children with severe retardation are almost fully dependent for their activities of daily living.

  • Profound mental retardation - Children with profound retardation will need intensive support for the rest of their lives. They are completely dependent on the family for their activities of daily living.

Q10) Is it important to send the child to school?

Yes, of course. It is extremely important that the child be sent to school, either normal or special school depending on the severity of intellectual disability. It is important that they be given exposure to a learning environment, peers of their age and capabilities from an impressionable age itself.

Special schools provide individualized education, addressing specific needs. Student to teacher ratios are kept low, depending upon the needs of the children. Special schools provide modifications to make learning simpler.

Q11) How does cell therapy work?

The biological task of stem cells is to repair and regenerate damaged cells. Cell therapy utilises this function by administering these cells in high concentrations directly in and around the damaged tissue, where they advance its self-healing and repair.

In children with Intellectual Disability, generally, certain areas of the brain like the frontal cortex and temporal lobe are damaged or functioning less, which can be seen on the PET CT Scan brain. Stem cells home on to these sites of damage and help improve functioning of these areas.

Q12) Are there ethical concerns surrounding adult stem cell research and therapy?

Bone marrow transplantation has been used successfully for genetic disorders of blood, such as sickle cell anemia, thalassemia, as well as cancers such as leukemia. Since our therapy uses these very cell, which are harvested from the patient's own body (autologous cells), there are no major ethical concerns. Ethical concerns are primarily on the use of embryonic stem cells (which we do not use).

Q13) Does the treatment have any side effects?

Bone marrow transplantation has been used successfully for genetic disorders of blood, such as sickle cell anemia, thalassemia, as well as cancers such as leukemia. Since our therapy uses these very cells, which are harvested from the patient's own body(autologous cells), there are no major ethical concerns. Ethical concerns are primarily on the use of embryonic stem cells(which we do not use).

In case of children with seizures, or previous history of seizures or an abnormal EEG, a small possibility of triggering seizures can be there. However, proper antiepileptic cover/drugs, could circumvent this problem.

Q14) How long will it take me to know that my child has benefitted from the treatment?

Maximal improvements are seen around 3-6 months after the treatment. However, in many patients there are slow progressive improvements that continue for several months/years later. Most patients do show some immediate improvements also i.e. before the discharge, in some of their symptoms.

Q15) Is the transplantation of the stem cells done once or more than once?

The decision to do the therapy a second time is taken after seeing the progress/improvements after the first therapy. A complete assessment will be done by the rehabilitation team, certain special imaging tests, such as PET CT Scan of the brain, would be repeated and then a second treatment may be recommended. This may be done anytime between 3-6 months of the first therapy.

Q16) Can other treatments be taken at the same time?

We will review what other medications the patient is already on. In most cases, we do not discontinue any already going on treatment. However, this is decided on a case by case basis. Please inform us about any medications you are taking beforehand.

Q17) Will my child improve after cell therapy?

In NeuroGen Brain and Spine Institute, we have treated over 450 patients with Intellectual Disability. They were administered with autologous stem cells, intrathecally. On follow up, majority of the patients improved in various domains of symptoms such as cognition - attention, concentration, learning, speed of processing and grasping, social interaction, communication, toilet training, hyperactivity, sitting tolerance, self-care, etc. This consequently, relieves the pressure of the caretaker and the family. Overall mental development is improved which is recorded as improvement in IQ as well.

Case reports

Case Report 1

An 18 year old case of Intellectual disability, Miss RT underwent Cell therapy at NeuroGen twice. At the time of first Cell therapy, she had the following chief complaints as reported by the parents:

  • She could not pay attention in studies at school.

  • Her social interaction was affected. She would not come out of her room if there were guests at home. She could not make friends easily at school or build a good rapport with the teacher.

  • There was presence of irrelevant aggressive behavior post which she would even hit the mother and father.

  • Her speech was not clear, which was also one of the reason which affected her social interaction with other people apart from her family.

  • Poor memory in terms of studies.

  • Poor learning capacity. For example, not being able to read numbers, unable to identify basic colors, shapes or alphabets.

  • Difficulty in taking care of herself. For ex: dressing, combing her hair, sleeping alone etc.

  • Difficulty in reading and writing in spite of teaching her several times in school.

  • Her IQ when tested at first, was 60 indicating Mild Intellectual disability.

However, after doing cell therapy and following a regular rehabilitation program at home, there has been a drastic change and improvement in her condition. The parents report the following improvements after Cell Therapy when they came in for a second time.

Learning and Academics:

  • Her learning capacity and grasping power improved from before. She can now read numbers from 1 to 50 after 7 months of undergoing the treatment.

  • She can identify shapes and matches them independently without any help.

  • She can now recognize 4 basic colors - Red, Blue, Green and Yellow.

  • She can now form stories by looking at the pictures shown, which has helped her improve her communication.

  • She can now play board games and solves 30 pieces of puzzles independently without seeing the picture, within a span of 4 minutes.

  • She can fix letters and can make small words out of it. For example, Kite, Gate, Moon, Cake, etc.

  • Her memory has also improved significantly. She can now write answers in exams, without any help.

  • She has learnt Origami at school, does paper folding, but requires assistance at times.

Language, Speech and Communication:

  • Her speech is clearer than before.

  • Her vocabulary has improved and she can now communicate better.

  • She reports what has happened in school after coming back home.

  • She is able to answer questions appropriately.

  • She is also able to ask for her basic needs and wants, which was not there before.

Social Interaction:

  • She has now made a good rapport with everyone in her school.

  • She has made new friends and plays with them.

  • Now she doesn't sit alone inside her room when guests arrive. Instead, she greets them and asks them for water. She can now sit with them in the hall along with everyone else.

Activities of daily living:

  • She can now dress by herself.

  • She can comb her hair without any help.

  • She keeps her room neat and tidy.

  • She can even fold her own dresses and keep it properly in the wardrobe.

Case Report 2

A 13 year old male child and a known case of Intellectual Disability, Master DH was a full-term, C-section delivered baby, and weighed 3.7 kgs at the time of birth. His birth cry was immediate. No neonatal complications were reported. However, he had febrile convulsions at the age of 4 months. He was diagnosed with Intellectual Disability at the age of 5 years due to delayed milestones and speech. He had been going to a mainstream school but had minimal learning in the school.

He came to the hospital with the following chief complaints:

  • Poor attention and concentration. He could not focus on any task at hand for more than 1 or 2 minutes.

  • He could only follow 1 step basic commands.

  • Age-inappropriate cognition and problem solving.

  • Poor awareness and judgment.

  • Weak game concept.

  • Exaggerated and inappropriate laughing.

  • Low sitting tolerance. He was always restless and would often leave his seat.

  • Unclear and limited speech. Repetitive speech was also present.

  • Social interaction was minimal and usually restricted to his family members.

  • Academically, he lagged severely. Reading and writing was affected.

  • Dependent for ADLs.

  • No regulation of hunger, thereby, leading to overeating.

  • Affected body coordination.

His Social Quotient(SQ) at the time of admission was assessed to be 50, suggestive of Moderate Intellectual Disability.

He underwent Cell treatment, post which he followed a rigorous regime of rehabilitation at home where he underwent Occupational Therapy and Speech Therapy everyday under a registered practitioner.

Post 8 months, they reported a deluge of improvements in the child, in various aspects like:

  • Attention and concentration became more stable.

  • He could comprehend and follow more complex commands and did not require as many repetition of commands. He engaged in household chores.

  • He started participating in group games and social play.

  • Exaggerated and inappropriate laughing ceased.

  • Sitting tolerance increased manifold. He was now able to sit in one place for 3-4 hours without leaving his seat and didn't get as restless as earlier.

  • Eye contact became more stable.

  • Aggressive behavior became minimal.

  • The clarity of speech improved. He also started blowing and sucking.

  • He made new friends and was much more interactive with people outside the house. Communication improved as well. He was also able to hold long conversations with people giving appropriate and relevant answers. He started attending family functions.

  • He could sing songs fluently without getting stuck.

  • He could convey more complex needs now and expressed his feelings.

  • Memory and grasping improved significantly. The number of trials required to grasp something new went down drastically.

  • Academically, he started reading 4-letter words, could read the newspaper and comprehend what was read. He also started writing.

  • Object identification improved.

  • He became independent for some of his Activities of Daily Living(ADLs). Eating became tidier. He became partially independent for brushing, bathing and dressing self. He also became toilet trained.

  • He could recognize and regulate his hunger needs thereby stopping excessive eating.

  • Body coordination became better and he learnt cycling.

  • His Social Quotient increased from 50 to 55.