[When do I give which antidepressant in the individual case?].

The reaction to sleep deprivation (SD) and the changes in MAO activity resulting from sleep deprivation were tested on 60 depressive patients as predictors for antidepressant drug treatment. An increase in MAO activity after SD indicates a future response to Maprotiline. A decrease in MAO activity indicates a future response to Clomipramine. An improvement in mood after sleep deprivation is a predictor for a future response to Clomipramine. If this effect of sleep deprivation fails to appear, the future effectiveness of Maprotiline is indicated. An attempt is made to subdivide the predictor variables into two groups: 1. so-called static predictor variables such as sex, diagnosis, age at onset of first illness and other socio-demographic data and 2. dynamic predictor variables such as, for example, reaction to SD, acute reaction to the drug, course of treatment during the initial days, diurnal variations of mood and increase in the serum level during the initial days. It is explained why static variables can have scarcely any predictive value, whereas dynamic variables are more to the point and are, therefore, better suited for making a prognosis of the treatment success with a particular antidepressant.