Mental retardation, more commonly known as intellectual disability (ID), is a condition in which a person has below-average general intellectual function and has difficulties in learning basic skills necessary for daily living. It is diagnosed before the age of 18. Approximately 1-3% of human population has been found out to be suffering from ID. In majority of such cases, the abnormality exists for the entire life. Anyone, irrespective of the age or gender, may become a victim of this disorder. It can be caused by a wide variety of factors, such as congenital disorders, chromosomal abnormalities, genetic defects, malnutrition, toxins, trauma, and inherited metabolic disorders. Mental retardation symptoms are quite prominent and are easily noticeable.
ID is basically grouped into four types, viz., mild, moderate, severe, and very severe or profound. A person diagnosed to be suffering from mild ID scores between 50-70 on the standardized intelligence quotient (IQ) tests. The score for a person with moderate ID lies between 35-50. In case of severe intellectual disability, the patient scores between 20-40 on the IQ test. There can be some unfortunate cases where the IQ score is in the range of 20-25. Such a case is known as profound intellectual disability. Following is a discussion of the symptoms of ID according to its various types.
The symptoms of mild ID in children often go neglected till they enter an educational setup. The most common symptoms are learning difficulties and poor social skills. Such a child can reach the educational plateau up to grade 6. Beyond this, his/her educational attainment is very difficult or impossible. With age till adulthood, the child may learn enough job skills and life skills to carry forward life on his/her own.
Children with moderate ID reach developmental milestones a bit later than their peers do. These are the earliest observed symptoms infants. Such a child faces difficulty in learning basic communication, and social, operational, and academic skills. He/she lacks the ability to retain information and remember things. This makes the child unable to learn even simple life skills. Such a child lacks curiosity, logical thinking, and problem solving capability. He/she needs constant supervision and care for survival. Such a person can achieve self-support till adulthood.
A person suffering from severe intellectual disability shows all the above mentioned symptoms of mild and severe type to a much greater degree since childhood. In addition to these, such a person shows aggressiveness and a tendency to self injury. In a majority of the cases of severe ID, the child is not able to learn the basic life skills. He/she needs another person's nursing, supervision, and care throughout his/her entire life.
Profound ID in children is observed right from infancy.There is no muscle coordination seen in the infant. He/she is not able to reach basic developmental milestones, like talking, walking, crawling, sitting up, etc., as expected with age and growth. However, with age, though the child may learn some basic skills of self care, he/she requires constant care and supervision throughout his/her life.
Symptoms of intellectual disability are the indications of mental abnormalities. A doctor confirms the condition with the help of a number of diagnostic tests and exams. Generally, if the Denver Developmental Screening Test shows the adaptive behavior score to be below average and the IQ score below 70, ID is confirmed (degrees or stages depend on the actual results).
Disclaimer: This article is for informative purposes only, and should not be used as a replacement for the advice of a mental health expert.