ABSTRACT
Time is an important dimension in psychiatry for the same reason that it is important in physiology. Psychiatric epidemiologists can follow the example of physiologists by developing a visual representation of the life chart, which makes behavior over time visible and at the same time avoids obscuring reality by complex statistical permutations. In order to use Skinner's model of the cumulative record and Adolf Meyer's life chart as important tools in psychiatric epidemiology, two subordinate principles must be noted. One cannot advocate life charts and cumulative records without emphasising the importance of prospective designs. Psychiatric epidemiology must learn to pay as much attention to natural protective factors as it currently does to risk factors, and psychiatry must learn to pay as much attention to natural healing processes as it does to therapeutic intervention. It is essential that longitudinal studies be kept simple, and that global variables be constructed by aggregation of the individual items.
