Aging brains- Use it or lose it...

Ageing brains and challenging thoughts

Jane Smith, deputy editor, BMJ

jsmith@bmj.com

I was heartened by this week’s Analysis on the ageing brain, which tries to counter some of the fear of cognitive decline that accompanies ageing (doi:10.1136/bmj.d6288). Marcus Richards and Stephani Hatch acknowledge that some cognitive skills do decline with age, but point out that people continue to learn and develop a rich set of cognitive skills. While recall of detailed information "bound to time and space" is sensitive to age related decline, memory for more abstract information is well preserved, and may actually improve with age. Cognitive capability and mental wellbeing are mutually supportive—and, say the authors, there is some evidence that continuing to work beyond traditional retirement may benefit cognitive function, possibly on the principle of "use it or lose it."
So what is there in the rest of this issue that might provide food for detailed recall for younger readers and prompt mature reflection in older brains?
Let’s start with perhaps the most challenging subject of all. Last week the BMJ hosted a conference on the health and security aspects of climate change (see last week’s editor’s choice (doi:10.1136/bmj.d6789 and http://climatechange.bmj.com/) and in this week’s feature Henry Nicholls describes the scenarios painted by the various experts from the military, population health, and earth and environmental sciences—and their insistence that global warming needed to be reduced radically from the temperature rise of 4-5°C that it is currently heading for (doi:10.1136/bmj.d6893). He quotes one speaker’s attempt to bring that close to home. "My younger son will be in his early 50s at that point, and that’s not a world he will survive in."
Tony Delamothe touches on other sorts of survival in his Observations article on child sex offenders (doi:10.1136/bmj.d6908). Against a background of vilification of paedophiles—including a savage murder of a paedophile in a British prison and views that such people "should be killed at birth"—Delamothe starts to probe what we know about paedophilia: it’s relatively common (as prevalent as schizophrenia), reconviction rates are low compared with other violent crimes, and there is evidence that treatment can help. He wants to see more enlightened attitudes towards paedophiles, though he concedes that if Lolita were published now it would be unlikely to be lauded as one of the world’s greatest novels.
The tool published in this week’s Research Methods and Reporting is much less controversial. It’s a tool for assessing the risk of bias in randomised trials (doi:10.1136/bmj.d5928) and it’s necessary, say Julian Higgins and colleagues, because discrepancies between the results of systematic reviews examining the same question, and between meta-analyses and subsequent large trials, show that the results of meta-analyses can be biased, often because the included trials have biased results. So the tool, put together by Cochrane Collaboration methodologists, enables systematic reviewers to explicitly assess the risk of bias caused by the methods of randomisation, allocation concealment, blinding of participants, blinding of assessors, attrition from the trial, selective reporting—and any other source of bias. The authors hope their tool will improve the appraisal of evidence and ultimately lead to better designed trials.
And finally, James Owen Drife offers a selection of seminars to keep the brain active, illustrating that the status of "emeritus" brings with it no decline in the cognitive ability to make jokes (doi:10.1136/bmj.d6867).

Cite this as: BMJ 2011;343:d6953