Is Phosphodiesterase inhibition a new mechanism of antidepressant action?

Unlike conventional antidepressants, rolipram (a new approach in the treatment of depression) stimulates both the presynaptic and the postsynaptic component of monoaminergic transmission. Several double blind trials are under way to assess the clinical efficacy and safety of this compound. The present study was a randomized, 4-week interindividual double blind double-dummy comparison with desipramine in inpatients with major (DSM-III) and/or endogenous (ICD-9) depressions. After a minimum washout period of three days the patients received either 0.50 mg rolipram or 25 mg desipramine orally t.i.d. for the first three days, then 0.75 mg rolipram or 50 mg desipramine t.i.d. until day 28. Rating tests were based principally on the AMDP-system and the HAMD scale. The study showed no differences between the two drugs as regards the efficacy, but a definite trend in favour of rolipram as regards the side effects and, in particular, anticholinergic effects.