One or more pain symptoms are present in 65% of depressed patients, and anywhere from 5 to 85% of patients with pain will be suffering from depression, depending on the setting; there is a lower prevalence in general practice, and higher in specialty clinics.
Ameriški neuroendokrinolo Robert Sapolsky podobno trdi, da bi se odnose med stresom, anksioznostjo in depresijo dalo meriti in biološko dokazati.