Depression was only detectable after 14 days in IP3R2–/–animals (1-day depression: t-ratio, 7.3, p < 0.0001; 7–14-day upregulation: t-ratio, 3.7, p < 0.003; IP3R2–/– decay between P0 and P14: p = 0.0426, Mann–Whitney U test). This evidence concerns the gene ITPR2 and depressive symptom measurement.