Among the metabolic and clinical variables, patients on insulin or combined insulin and oral treatment, those taking a higher number of medications, those with co-morbid heart disease or a higher number of co-morbidities, and higher BMI, FBS and HbA1c values were all found to be significantly associated with a greater risk for depression, for both questionnaires and both methods of questionnaire completion. This evidence concerns the gene INS and major depressive disorder.