With the aim to ascertain the contribution of psychiatric comorbidity to the elevated rates of premature mortality linked to the presence of noncommunicable diseases, researchers herein investigated people with common noncommunicable diseases, with and without psychiatric disorder comorbidity, for their risks of premature mortality and suicide.

• Using national registers in Sweden, over 1 million patients born between 1932 and 1995 and diagnosed with chronic respiratory diseases, cardiovascular diseases, and diabetes were investigated.

• Death of more than 7% of the patients occurred within 5 years, and death by suicide was reported for 0.3%.

• Patients with psychiatric comorbidities showed more than doubled of the risks when compared with those without such comorbidities.

• Identification and diagnosis of most of the psychiatric comorbidities were made before the noncommunicable diseases.

• Comparison of each of the patients with their unaffected siblings allowed identification of familial risk factors that were shared between the siblings (eg, genetic and childhood environmental risk factors).

• There appeared consistent correlation between psychiatric comorbidity and elevated rates of premature mortality and suicide in the sibling comparison analyses.