Brain shrinkage appears to have no impact on an individual's capacity to think or learn

Jun 10 2005

Brain shrinkage, a common symptom of ageing when people hit their 60's, appears to have no impact on an individual's capacity to think or learn, according to Australian National University (ANU) research.

The research is part of a 20-year study by the ANU Centre for Mental Health Research called PATH Through Life and suggests a revision of long-standing views on the impact of age-related brain shrinkage.

Professor Helen Christensen, the Director of the Centre for Mental Health Research (CMHR), said the findings challenged traditional beliefs about the impact of ageing on the brain.

"The common belief is that the brain shrinks with age and that this shrinkage is linked to poorer memory and thinking. There is also a belief that greater education, or continued, sustained intellectual activity might allow people to better accommodate the effects of brain ageing," Professor Christensen said. "Our findings do not support these beliefs. It is known that the brain shrinks over the course of a person's life, although the exact trajectory is not well understood, and there are huge individual differences.

"In this study, we found that, on average, men aged 64 years have smaller brains than men aged 60. However, despite this shrinkage, cognitive functions - like memory, attention and speed of processing - are unaffected.

"In the present study, we found no relationship between brain shrinkage and education level".

Low educational attainment has been found to predict the development of major memory difficulties and the recognition of dementia in previous work. However, little is known about whether education is protective of brain changes in the general population.

"Our findings do not support the role of education in protecting against either brain change or cognitive performance.

These findings are good news for the large proportion of baby boomers out there - and probably better news for the baby boomer women who show no evidence of brain shrinkage over this short period of time".

The ANU researchers conducted a combination of MRI scans and surveys of 446 people in their 60's in Canberra and Queanbeyan.

Their findings are the latest from the PATH Through Life project, which was initiated by the CMHR in 1999.

Other outcomes of the project have included:

• Strong associations between childhood adversity and adult depression. Factors most strongly related to depression include: mother's depression, reports of neglectful upbringing, too much physical punishment, having an unaffectionate father, and experiencing a lot of family conflict.
• Bisexual people tended to suffer more from anxiety, depression and suicidal tendency than homosexual or heterosexual study participants.
• Young Australian adults are the least likely to obtain GP care, compared to other age groups - despite evidence of significant mental health problems, such as tendencies towards suicide and substance abuse. The study found that those who used GPs were most likely to be female, to have been or be undertaking higher education and to be living with children. Young adults were also identified as having poorer physical health, more chronic diseases and higher levels of suicidal ideation when regularly using marijuana.
• Elevated symptoms of depression, anxiety and negativity were related to levels of tobacco consumption and marijuana use for both young men and women.

"The PATH Through Life project is set to shed much information on health, wealth and happiness, and hopefully show the way for health care and targeting of support to better meet the needs of individuals at different stages of life," Professor Christensen said.

http://www.anu.edu.au