Alterations of NTF expression, including BDNF, are involved in the development of a variety of CNS diseases, including neurodegenerative disorders (Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis) as well as psychiatric disorders (depression and schizophrenia) [14–16]. This evidence concerns the gene BDNF and depressive symptom measurement.