There are not so many studies on DM1 and depression, but one important review on the subject evidences a biological link: increased circulating cytokines associated with autoimmune diabetes, the lack of insulin affecting neurogenesis and neurotransmitter metabolism, the effects of chronic hyperglycaemia and those of iatrogenic hypoglycaemia and a hyperactivity in the HPA axis [31]. The gene discussed is INS; the disease is depressive disorder.