Endophenotypes of depression and anxiety

Progress in neurobiology (neurotransmitters, second messengers, early genes, trophic factors, ion channels, genetics, brain imaging) has changed the perspective on psychiatric illness in the last decades, particularly in the field of depression [1] and anxiety [2]. Difficulties in the discovery of susceptibility genes have been attributed to the etiological heterogeneity of the clinical phenotype of the disease [3]. Endophenotypes [1–4], e.g. neurobiological correlates of depression and anxiety which are genetically determined and mostly stable over time might be better targets for future research and/or treatment strategies. Practical implications of the neurobiology of depression and anxiety are discussed.