Thus, the Crtc1 knock-out (Crtc1−/−) mouse was shown to be a useful model to study the pathways and mechanisms linking metabolic diseases with depression [21, 22, 28, 29] and to understand associated resistance to classic antidepressants, in particular to fluoxetine [30, 31]. The gene discussed is CRTC1; the disease is depressive symptom measurement.