The relationship between psychosocial traits and glycaemic control and complications was examined in 130 adults (83 men, 47 women) with insulin-dependent diabetes mellitus. Abnormal depression ratings were observed in more women (19.1%) than men (12.0%), p less than 0.01, whilst obsessive symptoms were recorded more frequently in men (41.0 v 21.3%, p less than 0.01). Abnormal anxiety ratings were present in roughly 8-13% of men and women, although a notably low feeling of insecurity rating was observed more frequently in men (56.5%) than in women (38.3% of cases), p less than 0.05. Psychological scores were related to age, employment status and social class, but not to duration of diabetes or glycaemic control. The anxiety, depression and obsessive ratings correlated with one another (rs range 0.24-0.62, all p less than 0.001). Higher anxiety and depression ratings or overt psychological dysfunction was recorded in patients with neuropathic symptoms and signs, impotence, macrovascular disease or proliferative retinopathy. It is concluded that the presence of diabetic complications and adverse social circumstances are more relevant to psychological status than glycaemic control.