Along with fewer depression symptoms, it was also linked to better sleep.
Higher intelligence reduces the risk of mental health problems, including depression, research finds.
A higher IQ is linked to less self-reported depression symptoms, fewer sleep problems and better overall mental health.
The conclusions come from a study of 5,793 people who were followed for decades.
The results showed that those with higher IQ scores in their youth had better overall mental health when they were 50-years-old, compared to those with lower IQs.
Along with fewer depression symptoms, those with higher IQs also slept better in middle age.
The authors conclude that IQ may have a protective effect against depression in middle age:
“Higher pre-morbid intelligence was significantly associated with less depression, less sleep difficulty, and a better overall mental health status at age 50.
These results were similar to those found at age 40 and they suggest that higher intelligence in youth, in both men and women, may have a protective effect on mental health into middle age.”
However, people with higher IQs were more likely to have received a depression diagnosis by age 50.
This seems to contradict the finding that they self-reported lower symptoms of depression.
The researchers think it may be because intelligent people are more likely to recognise depression and get help for it.
They write that one possible reason is that:
“…people with higher intelligence may also have higher mental health literacy.
Those with higher intelligence might be more able to identify their symptoms of depression, which could motivate them to consult a doctor for diagnosis and advice; they might also be likely to have accurate reporting of such diagnoses in the health module.”
The study was published in the journal Intelligence (Wraw et al., 2018).