Scans of retired British professional football players have shown structural differences in the brain and high rates of anxiety and depression, but without any signs of mental decline, in a study aimed at determining whether repeated impacts, such as heading the ball, have an effect related to the risk of dementia. The study, conducted by researchers at Imperial College London, included 142 former players aged between 30 and 60, and they were compared with 56 ordinary people of the same age group who have no history in sports that require physical contact or have previously suffered concussions. After using questionnaires and tests to measure cognition, the researchers analyzed structural MRI brain images from a qualified subgroup of 142 players and 40 ordinary people to check for differences in gray matter volume. The study authors, who presented the results at the Alzheimer's Association International Conference on Sunday, explained that the research is part of a large effort by scientists to address repeated head trauma as a modifiable risk factor that may potentially contribute to dementia in later life, similar to how doctors treat high blood pressure or cholesterol. The study lays the groundwork for what is intended to be a longitudinal study of these players, whom the researchers plan to monitor every two years. Thomas Parker, lead author of the study and consultant neurologist at Imperial College London, said: 'This field is taking a more holistic view of brain health and dementia risk.' After adjusting for factors such as age and education, the former players scored well, as expected, on memory and thinking tests, and showed no significant differences compared to ordinary people. The athletes reported much higher rates of mental health problems: 31 percent reached the threshold for clinical depression, compared with nine percent in the other group, and 42 percent of athletes reported clinical anxiety compared with 25 percent. The researchers found that brain scans of former players showed less brain tissue in regions controlling memory and emotion compared to the other group, but only two percent of former athletes showed individual signs of severe brain shrinkage indicative of active and advanced neurodegeneration. The study has not yet undergone peer review. The researchers expect to submit a paper with a larger sample and additional analyses later this year.