[Research in psychogeriatrics. Various theoretical and methodologic aspects]

The rapid increase in individuals aged 65 years old and more in the general population has directed attention to geriatrics, a medical specialty concerned with the study, prevention and treatment of pathological conditions in the aged. Among these conditions, frequent psychiatric disturbances occur and therefore it is widely recognized the increasing role of psychogeriatrics. A comprehensive review of theoretical and methodological issues related with research in psychogeriatrics is presented. In a short introduction, the state of the art in some main areas is analyzed. It is pointed out that controversial and unsolved problems still influence the ongoing research in this field. The use of different theoretical models is discussed, taking into consideration their specific scope and drawbacks. Psychopathological phenomena in the elderly are under the influence of a variety of etiologic and pathogenic factors and the conclusion arises that an adequate conceptual framework can be provided by systemic and multifactorial models. However, in order to preserve their explicatory power, they require valid and reliable definitions of all variables involved--not only independent and dependent variables, but also mediating variables--as well as clear hypothesis on their relationships. Different approaches for the fulfillment of these requirements are discussed.