BDNF and depressive symptom measurement: Studies suggest that stress during early developmental stages can alter the methylation patterns of the Bdnf gene on different brain regions of the offspring, causing a decrease in their expression in the hippocampus and prefrontal cortex [11], which has been implicated in various psychological and neurological disorders, such as anxiety, depression, schizophrenia, Parkinson’s, and Alzheimer’s disease [12,13].