Table 2.

Hypotheses on the association between schizophrenia and diabetes (adapted from Leucht et al. [2007a, 2007b]).

Environmental	Pharmacological	Biochemical	Other possible links
Sedentary lifestyle, lack of exercise	Weight-inducing and diabetogenic effect of some antipsychotic drugs	Overexcitement of the sympathetic system, hypersecretion of adrenalin	Inefficiency of the liver
Smoking, substance abuse	Effect of antipsychotic medication on liver metabolism	Dysregulation of the hypothalamic–pituitary–adrenal axis	Positive family history of diabetes (genetic)
Adverse diet, poor nutrition, high intake of fast food, lack of understanding of dietary principles		Hyper-cortisolaemia, excessive visceral fat, hyperglycaemia, hyperinsulinaemia, insulin resistance	Low birth weight
Lethargy, sedation		Anti-insulin factor
Inadequate medical or public healthcare, poor adherence to prescribed medication		Abnormal glucose metabolism
Stressful experiences (hospitalization, psychotic symptoms)		Sex hormones and oestradiol mediating weight gain