Specifically, the NK-1 receptor and SP are involved in emotional responses to stress, suggesting that an alteration in the tachykinergic system may be the key to triggering pathogenesis such as depression (SP expression has been shown to increase during depression [121] whereas the genetic deletion of its receptor induces an anxiolytic and antidepressant effect [132]). Here, TACR1 is linked to depressive symptom measurement.