Immunodeficiency strongly linked with suicide, psychiatric disorders: JAMA
Sweden: Primary humoral immunodeficiency (PID) is associated strongly with suicidal behavior and lifetime psychiatric disorders, suggests a recent study in the journal JAMA Psychiatry. The association was found to be more stronger in women and could not be explained fully by co-occurrence of autoimmune diseases. Also, the patients with both autoimmune disease and PID were at the highest risk of suicide and psychiatric disorders.
PIDs are rare deficiencies of the immune system that are associated with adverse health problems such as autoimmune disease and recurrent infections. The etiological importance of disrupted immune function in psychiatric disorders has been demonstrated in many studies. However, not much is known about neuropsychiatric consequences resulting from the underproduction of homeostatic antibodies. Considering this Josef Isung, Karolinska Institutet, Stockholm Health Care Services, Region Stockholm, Stockholm, Sweden, and colleagues aimed to establish whether PIDs that affect antibody function and level are associated with lifetime psychiatric disorders and suicidal behavior. And also, whether this association is explained by the co-occurrence of autoimmune diseases.
The study included more than 14 million individuals living in Sweden from January 1, 1973, through December 31, 2013. The researchers collected register-based data on exposure, outcomes, and covariates. Individuals with a record of PID were linked to their full siblings, and a family identification number was created. Data were analyzed from May 17, 2019, to February 21, 2020.
The primary outcomes included lifetime records of 12 major psychiatric disorders and suicidal behavior, including suicide attempts and death by suicide.
Key findings of the study include:
- A lifetime diagnosis of PID affecting immunoglobulin levels was identified in 8378 patients (59% women).
- A total of 4776 clusters of full siblings discordant for PID was identified.
- After adjusting for comorbid autoimmune diseases, PIDs were associated with greater odds of any psychiatric disorder (adjusted odds ratio [AOR], 1.91) and any suicidal behavior (AOR, 1.84).
- The associations were also significant for all individual psychiatric disorders (range of AORs, 1.34 for schizophrenia and other psychotic disorders to 2.99 for autism spectrum disorders), death by suicide (AOR, 1.84), and suicide attempts (AOR, 1.84).
- In the sibling comparisons, the associations were attenuated but remained significant for aggregated outcomes (AOR for any psychiatric disorder, 1.64; AOR for any suicidal behavior, 1.37), most individual disorders (range of AORs, 1.46 for substance use disorders to 2.29 for autism spectrum disorders), and suicide attempts (AOR, 1.41).
- Joint exposure for PID and autoimmune disease resulted in the highest odds for any psychiatric disorder (AOR, 2.77) and any suicidal behavior (AOR, 2.75).
- The associations with psychiatric outcomes (AORs, 2.42 vs 1.65) and suicidal behavior (AORs, 2.43 vs 1.40) were significantly stronger for women than for men with PID.
"Primary humoral immunodeficiencies were robustly associated with psychiatric disorders and suicidal behavior, particularly in women; the association could not be fully explained by co-occurring autoimmune diseases or by familial confounding. Future studies should explore the underlying mechanisms of these associations," concluded the authors.
The study, "Association of Primary Humoral Immunodeficiencies With Psychiatric Disorders and Suicidal Behavior and the Role of Autoimmune Diseases," is published in the journal JAMA Psychiatry.