Mental health and mental illness are still taboo, and not much awareness exists around this kind of topic. Many myths and beliefs are associated with mental illness. One common misconception is that people suffering from mental illnesses are poor and/or less intelligent.

The reality is that many studies have shown that most people with mental illness have average or above-average intelligence. Regardless of IQ, social position, or financial level, mental disease may impact everyone, just like physical sickness. Researchers have found no consistence association between lower IQ and mental illness. Some have stated that people with higher IQs are more likely to suffer from mental illness than people with lower IQs. 

Schizophrenia and related disorders, psychotic disorders, adjustment disorders, personality disorders, and alcohol and substance-use-related disorders are significantly associated with low IQ scores. For most diagnostic categories, test scores are almost always positively associated with the length of the interval between testing and first admission. ICD mood disorders, as well as neuroses and related disorders, are not significantly associated with low IQ scores.

Mental Retardation:

Mental retardation is a type of mental illness that is described by assessing the intelligence quotient of an individual. A child with an IQ between 70 and 84 is said to have borderline mental retardation; an IQ between 50 and 69 is mild mental retardation; and an IQ between 49 and 35 is modulated mental retardation. A child with an IQ between 20 and 34 is severe mental retardation, and those with an IQ less than 20 have profound mental retardation.

With specialized instruction targeted at developing self-help abilities, children with mild mental impairments can become largely independent.

Children with mild mental retardation can talk, speak, and carry out daily routine activities. They can be educated to a certain extent so that they can lead independent lives. Children with borderline mental retardation are usually poor performers in school, but with proper training, they can lead an independent, normal life.

Pseudo Mental retardation

A child with normal intelligence may appear to be mentally retarded due to other problems that prevent him or her from performing daily activities efficiently. Deafness, blindness, emotional problems, speech problems, cerebral palsy, and psychiatric problems may be associated factors leading to inadequate performing skills in these categories of patients. 

Treatment 

Mental retardation is not structured to "cure" the disorder; rather, treatment module goals include reducing safety risks like helping an individual maintain safety at home or school and teaching appropriate and relevant life skills. Interventions should be based on the specific needs of individuals and their families, with the primary aim of developing the person's potential to the fullest.

Medications are required to treat co-morbidities like aggression, mood disorders, self-injurious behavior, other behavioral problems, and convulsions, which occur in 40% to 70% of cases.

Conclusion:

There is a significant link between lower IQ and common mental illness. Many studies and research have been done to state the same but are unable to establish this fact. There are marked inconsistency in the results of various studies. Though some state that some mental illness may occurs in people with low IQs, there are studies that also state that people with higher IQs are more susceptible to mental illnesses like anxiety disorders and other mental illness. On the other hand, mental retardation is one kind of mental illness that is diagnosed and characterized by low IQ levels. Remember that addressing these issues involves both promoting mental health and encouraging adaptable thinking and behavior in proactive ways.