A large proportion of the variability in drug response is due to genetic factors, and this variability affects therapeutic effects and adverse reactions, so that the same dosage of a drug can be beneficial to some patients, but ineffective to others. The drugs known as selective serotonin reuptake inhibitors (SSRI) belong to a pharmacological class used in the management of a number of diseases related to serotonin, especially depression. The aim of this paper is to collect data from the literature about the association of candidate genes with response to SSRI, providing an overview on the current knowledge of this subject. The effect of SSRI treatment depends on the variability in genes coding proteins involved with the role of serotonin in the brain. The new data from the Human Genome Project allowed detection of these variations, and several of them proved to have pharmacogenetic importance. Therefore, some of the genes related to SSRI pharmacogenetics are already known. This reinforces the need of larger prospective investigations to determine the real use of this knowledge in clinical practice as to the possibility of determining the right dosage, and the right drug to each patient, a practice that has been called "personalized medicine".
Susceptibility genes; variability in drug response; association studie
