In clinical trials of antidepressant treatments, a depression rating score is usually
measured at several points of time for each patient. We propose an approach to fit
data from this type of clinical trial using an exponential mixed-effects model. Compared
to previous proposals, this approach has the advantage that individual recovery curves
are fitted rather than curves of means. Furthermore, no artificial fixing of model
parameters is needed as in other approaches. The flexibility of the proposed model
is shown for various situations. The approach is illustrated by an example from a
placebo-controlled study for the treatment of depression with St. John’s Wort (Hypericum
perforatum).
Keywords:
Nonlinear Regression - Mixed-Effects Model - Depression - Hamilton Rating Scale for
Depression
