[Psychological functioning and aging. Learning from longitudinal studies]

Population-based longitudinal studies are very useful tools for investigating the characteristics of the aging process among different geographical and socio-cultural contexts. On the other hand, these kind of projects look at a wide range of key issues of aging. In this review, most recent psychological findings in this field are analysed. The increasing interest in longitudinal studies for psychological variables is shown, as well as explicit links with other areas of study. Finally, main areas of improvement are identified according to future analysis of psychological variables, regarding both conceptual and methodological issues.