The Barcelona Brain Health Initiative: Cohort description and first follow-up.

The Barcelona Brain Health Initiative is a longitudinal cohort study that began in 2017 and aims to understand and characterize the determinants of brain health maintenance in middle aged adults. A cohort of 4686 individuals between the ages of 40 and 65 years free from any neurological or psychiatric diseases was established, and we collected extensive demographic, socio-economic information along with measures of self-perceived health and lifestyles (general health, physical activity, cognitive activity, socialization, sleep, nutrition and vital plan). Here we report on the baseline characteristics of the participants, and the results of the one-year follow-up evaluation. Participants were mainly women, highly educated, and with better lifestyles compared with the general population. After one year 60% of participants completed the one-year follow-up, and these were older, with higher educational level and with better lifestyles in some domains. In the absence of any specific interventions to-date, these participants showed small improvements in physical activity and sleep, but decreased adherence to a Mediterranean diet. These changes were negatively associated with baseline scores, and poorer habits at baseline were predictive of an improvement in lifestyle domains. Of the 2353 participants who completed the one-year follow-up, 73 had been diagnosed with new neurological and neuropsychiatric diseases. Changes in vital plan at follow-up, as well as gender, sleep quality and sense of coherence at baseline were shown to be significant risk factors for the onset of these diagnoses. Notably, gender risk factor decreased in importance as we adjusted by sleep habits, suggesting its potential mediator effects. These findings stress the importance of healthy lifestyles in sustaining brain health, and illustrate the individual benefit that can be derived from participation in longitudinal observational studies. Modifiable lifestyles, specifically quality of sleep, may partially mediate the effect of other risk factors in the development of some neuropsychiatric conditions.