Childhood cognitive ability not linked to depression in adulthood

There is no association between cognitive ability in childhood and depression in adulthood, a meta-analysis has found.

Cognitive abilities are the mental skills needed to carry out any task from the simplest to the most complex. They include mental processes related to the manipulation of information, such as perception, memory, logic and reasoning, and attention.

Some large longitudinal studies have shown that people with lower cognitive abilities are more likely to die prematurely or contract various diseases. These findings have led researchers to investigate whether a correlation exists between cognitive ability in childhood and depression in adulthood. Depression often starts in early adulthood, but is rarely detected in childhood. The researchers thought that if we consider cognitive ability as a measure of overall functioning of the body, it is possible that depression or precursors of depression in childhood might manifest themselves as lower cognitive abilities.

The meta-analysis, published in the Journal of Affective Disorders, looked at links between cognitive ability and depression symptoms, and found no association between cognitive ability in childhood and depression in adulthood.

The University of Edinburgh researchers looked at 18 scientific articles, which included data from 19 different groups of study participants, totalling 84,407 individuals. Between 44% and 100% of participants were female. Of these groups, nine were from the US, five from the UK, two from New Zealand, and one each from Australia, Canada, and Spain. All groups were from higher-income countries.

‘Mixed’ findings in existing literature

The cognitive abilities of the study participants were assessed at ages ranging from 4 to 18, using neurocognitive tests. The average age for the assessment of depression symptoms in these studies ranged from 18 to 84 years. Very few studies assessed depression symptoms after the age of 60.

The meta-analysis showed no association between cognitive ability in childhood and depressive symptoms in adulthood. This absence of correlation was found in both sexes and at all ages.

“This systematic review did not find an association between childhood cognitive ability and risk of depression in adulthood. Rather, it highlighted mixed findings of the existing literature, and emphasized the challenges in controlling for potential confounders when understanding key risk factors for depression across the life course,” the authors wrote.

A new report, meanwhile, has published data revealing the scale of the mental health crisis among children. The data, gathered from 5,000 children and young people in Bradford, suggests that one in five Year 9 pupils in the area have a probable eating disorder, and one in six 12-to-15-year-olds have self-harmed in the last 12 months, with a higher prevalence in girls (20%) compared to boys (13%).

The report, published by the research project Child of the North and the think tank Centre for Young Lives, calls for widening of Mental Health Support Teams to all schools, new “one-stop-shop” hubs for parents and children to find local support, and national roll-out of local wellbeing surveys to track the mental health of school children.

The study also says that the children surveyed cited a lack of sleep and loneliness as principal causes of their poor mental health. Dr Ruth Wadman, a research fellow at the University of York who worked on the study, said: “Our children and young people need good mental health and wellbeing to develop and flourish. There is an urgent need to step-up our efforts to prevent mental health conditions and to intervene early when they emerge. The report shows that schools can play a key role in promoting good mental health and wellbeing, both by harnessing the power of data and by listening to children and young people.”