Therapeutic drug monitoring in psychiatry

In medicine, there are two main methods of improving the healthcare provided: perfecting (optimizing) the existing ones and seeking new treatment procedures. Despite of tremendous development in the central nervous system research, current treatment of severe mental illnesses, such as schizophrenia and depressive disorder, is suboptimal. Nowadays, optimization of treatment in psychiatry includes therapeutic drug monitoring (TDM) and pharmacogenomic testing, which examines genetic variation involved in medication metabolism and drug action. The TDM enables to determine drug concentrations in blood and adjust the dose accordingly if clinical effects correlate better with drug blood levels than drug doses. The first international guidelines for TDM in neuropsychopharmacology were published in 2004 and regularly updated. The recent update provides therapeutic reference ranges for a majority of commonly prescribed psychiatric medications and gives example of patients regularly treated in clinical practice profiting from TDM (using antipsychotics and changing their smoking habits). TDM in psychiatry is an underused tool, given its ability to optimize treatment, as well as to improve treatment effectiveness.