IQ Scores and Mental Health Issues
Intelligence is the overall, or global, ability of an individual to act deliberately, think rationally, and cope effectively with the environment. Previous research has shown that individuals with intellectual disabilities with IQ <70 are at a higher risk of being diagnosed with one or more mental disorders. There was a study that investigated whether this was also true for individuals with IQs between 70 and 85.
In this study.
The data were drawn from a longitudinal follow-up study of individuals with low birth weight and a control group. The study compared the mental health of participants with borderline IQ, defined as a full IQ score of 70-84, to the mental health of a reference group with a full IQ score of 85 or higher.
Mental health at age 19 was assessed using the Schedule of Emotional Disorders and Schizophrenia for Lifetime School-Aged Children (K-SADS P/L), where a score meeting diagnostic criteria for mental disorders is defined as having a mental health problem.
In addition, participants completed the ADHD Rating Scale and the Autism Spectrum Index form (AQ). Logistic regression analysis was used to calculate odds ratios (ORs) with 95% confidence intervals (CIs) for high scores on the K-SADS.
Results.
30 participants with borderline IQ and 146 controls were included. Sixteen (53%) of the borderline IQ participants met the K-SADS diagnostic criteria for all diagnoses (OR: 6.2; CI: 2.6-14.9), compared to 18 (12%) in the reference group.
In particular, participants with borderline IQ were at excess risk for ADHD and anxiety, but these associations were slightly weakened when adjusted for birth weight and parents' socioeconomic status.
Conclusions.
Fifty-three percent of participants with borderline IQ were at higher risk for the psychiatric diagnoses assessed in the study, compared to about one in ten in the reference group, and the group with borderline IQ had higher total scores and higher scores on several subscores included in the Autism Spectrum Index form.
These results indicate an increased vulnerability to psychiatric disorders in individuals with borderline low intelligence quotient.
Melby, L., Indredavik, M.S., Løhaugen, G. et al. Is there an association between full IQ score and mental health problems in young adults? A study with a A study with a convenience sample. BMC Psychol 8, 7 (2020). Available at: https://doi.org/10.1186/s40359-020-0372-2
Summary
It is well known that people with low IQ are more likely to suffer from mental disorders, and the results of this study show that people with IQ scores below 84 are at higher risk for mental disorders.
Although poor development and disability based on the neurophysiology of the individual may be considered as a factor in mental disorders, in this case, the focus was on environmental problems rather than the individual's problems.
Events such as bullying from those around them, low self-esteem, and parental divorce are believed to cause the onset of disabilities, but I think that some sort of disability is likely to occur even if IQ is not a factor. However, if there is a deficit in self-esteem that can be avoided by the person himself, he may suffer from the disorder, so we have to think about how to interact with him.
