Researchers often use brain scans to look into the links between brain structure and mental-health problems. One problem with this is that it is hard to tell what brain changes or differences give rise to mental-health problems and what changes in brain structure are caused, either by psychological troubles or by the drug treatments for them. Researchers from Columbia University scanned 131 people between the ages of six and 54. Some people had had no family history of depression and were unaffected by the condition; some people had a family history of depression but had not developed it themselves and were deemed to be 'at risk,' and other people were suffering from it. Those participants who were at risk of developing depression had a 28% thinning in the right cortex compared to those not at risk of depression, and those participants with depression had a thinning on both left and right cortices. The thinning was on a par with that of people suffering from Alzheimer's disease. Dr Bradley Peterson, the author of the study, thought that having a thinner right cortex might lead to a greater risk of depression by disrupting people's ability to decode and remember social and emotional cues from other people. The researchers also carried out memory and attention tasks on the participants and found that the less brain material a person had in their right cortex the worse their memory and attention was.
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