The temporal association between type 1 diabetes mellitus (T1DM) and major psychiatric disorders, including schizophrenia, major affective disorder, autism spectrum disorder (ASD), and attention-deficit hyperactivity disorder (ADHD), remains elusive.

The specialized databases of catastrophic diseases and mental disorders and the longitudinal health insurance database of Taiwan National Health Insurance Research Database were used in current study. A total of 6,226 patients with T1DM and 62,260 age- and sex-matched controls were recruited between 2001 and 2010 and were followed until the end of 2011 for the identification of diagnoses of schizophrenia (International Classification of Clinical Diseases, Ninth Edition, Clinical Modification [ICD-9-CM] code: 295), bipolar disorder (ICD-9-CM codes: 296 except 296.2x, 296.3x, 296.9x, and 296.82), major depressive disorder (ICD-9-CM codes: 296.2x and 296.3x), ASD (ICD-9-CM code: 299), and ADHD (ICD-9-CM code: 314).

Cox regression analysis revealed increased hazard ratios of schizophrenia (12.28), bipolar disorder (13.80), major depressive disorder (10.41), ASD (14.52), and ADHD (8.19) in patients with T1DM compared with controls.

Our findings indicate the importance of clinicians closely monitoring the mental health condition of children, adolescents, and adults with T1DM. Additional studies should be conducted to elucidate the definite pathomechanisms of comorbidities between T1DM and major psychiatric disorders.