Oxytocin administration into the nucleus accumbens shell has been shown to reverse separation‐induced passive coping behaviour, and local knockdown of the oxytocin receptor induces depression‐like passive coping behaviour, suggesting that separation increases CRFR2 signalling, which lowers oxytocin transmission within the nucleus accumbens, resulting in depression‐like behaviour. This evidence concerns the gene OXTR and major depressive disorder.