As summarized in an autobiographical record (Baumann P. From serotonin to clinical psychopharmacology and pharmacogenetics. In: Ban, T.A., Healy, D. and Shorter, E., editors, Reflections on twentieth-century psychopharmacology. Budapest: Animula; 2004. p. 475-479), his main research areas comprise: development of biochemical assay methods (e.g. mass spectrometry); pharmacokinetics and pharmacogenetics of antidepressants and antipsychotics; role of cytochrome P-450 isozymes and MAO in the metabolism of psychotropic drugs, in vivo, and in human liver and human brain, in vitro; clinical relevance of therapeutic drug plasma monitoring and pharmacogenetics; pharmacovigilance in psychiatry; neuropsychopharmacology of psychotropic drugs, especially in relationship with serotonin; clinical phase II-IV studies.