IQ over time

Agonist

I'm wondering is it possible for IQ to drop about 50 points over the course of 20 years (say 170 to 120)? What kind of factors could contribute to this drop? Could the IQ points be regained by changing lifestyle or doing specific exercises? Could the kind of damage that would cause such a loss be limited to IQ or is It more likely that other aspects of a person would be compromised, e.g. physical and emotional impact.


In the case I'm referring to there have been life events that may or may not have contributed:
Intense psychotic episodes
ECT
Long term high dose antipsychotics, typical and atypical
Long term high dose benzodiazepines
Severe and enduring mental illness

I hope this is in the right forum and that you can refer me to papers on this subject. Thanks.

JuliusCaesar

Google Scholar is always useful when looking for papers. You could try looking using longitudinal studies, intelligence, factors, etc as key words.

This might be of some interest. And this on ECT.

But there are always going to be questions as to whether IQ is actually a good measurement of intelligence; how can you tell what factors influence it; is it genetic and fixed in stone or is it fluid over time etc etc. Then you need to be critical of the studies - are they reliable? How large is the sample size? etc etc.

Valmont

You could also look into the factors that might cause a person's working memory capacity to decrease given that intelligence is very strongly linked to working memory span. This article is a must-read if you have access.