The neuroprotective effects of nasally administered insulin that have already been noted in slowing down the progression of neurological conditions, such as AD, anxiety, depression, eating disorders, olfactory epithelium injury, Parkinson's disease, Phelan-McDermid syndrome and substance addition, are independent of peripheral insulin concentration [6, 26, 29, 30, 35]. Here, INS is linked to depressive symptom measurement.