This chapter discusses psychiatric drug therapy in special situations. None of the psychotropic drugs are completely safe during pregnancy or lactation. The risk and benefit ratio needs to be weighed on individual situations. The US FDA rates drugs used in psychiatry into five categories according to its safety in use during pregnancy. Risks of drug administration during pregnancy occur specially in first trimester due to teratogenesis or behavioral teratogenesis. Guidelines of drug therapy during pregnancy and lactation, pediatric/young adolescent age group, geriatric psychopharmacology, and antidepressants are also covered in this chapter.