Home » News » Increased Risk of Mental Illness if Sibling Hospitalized for Same Disorder
Increased Risk of Mental Illness if Sibling Hospitalized for Same Disorder

Increased Risk of Mental Illness if Sibling Hospitalized for Same Disorder

New research has allowed investigators to assess the individual risk of developing a mental disorder if a brother or sister has been hospitalized for the same condition.

Researchers completed a large survey using data from all patients hospitalized in psychiatric wards in Israel, and matched the information to their siblings.

They discovered having a sibling with schizophrenia increases your risk of developing the condition by a factor of 10, with increased risks of developing bipolar disorder and other mental disorders.

Investigators discovered similar risk profiles among siblings of patients with bipolar disorder.

Researchers explain that this is the first study to assess risk of developing any psychiatric diagnosis in siblings of all patients hospitalized for any type of mental disorder in an entire population.

The study finding were presented at the European College of Neuropsychopharmacology (ECNP) Congress in Vienna.

The lifetime chance of suffering a mental disorder is extremely high. It is estimated that each year 38.2 percent of the population suffers from a mental disorder, corresponding to 164.8 million persons affected in Europe, alone.

Experts have known that siblings of patients with major mental disorders have an increased risk of suffering from the same disorder, but until now the risks have not been quantified

In the new study, an international team examined the rates of mental disorders in the families of 6111 Israeli patients who had been hospitalized with schizophrenia, bipolar disorder, or depression.

They compared them to over 74,000 controls, age-and gender matched controls, taken from the Israeli Population Registry, which records all births, deaths, marriages, and divorces in the country.

By comparing the relative rates of mental disorders, they were able to show just how much more siblings are at risk of the same, and also other mental health conditions.

If a brother or sister has schizophrenia, a sibling has 10 times greater chance of themselves suffering from schizophrenia.

They also have six to eight fold increased chance of suffering from schizoaffective disorder, and seven to 20 times greater risk of suffering from bipolar disorder than the general population.

If a brother or sister suffers from bipolar disorder, then their siblings have four times greater chance of suffering from bipolar disorder, schizophrenia, and other psychiatric disorders.

“This is a large study which allows us to put meaningful figures on the risks of developing mental disorders after they have arisen in a brother or sister. The figures are quite striking, with 10-fold risk of developing schizophrenia, and similar risks once a sibling has developed bipolar disorder,” said lead researcher Mark Weiser, M.D.

Source: ECNP/AlphaGalileo


Increased Risk of Mental Illness if Sibling Hospitalized for Same Disorder

Rick Nauert PhD

Rick Nauert, PhDDr. Rick Nauert has over 25 years experience in clinical, administrative and academic healthcare. He is currently an associate professor for Rocky Mountain University of Health Professionals doctoral program in health promotion and wellness. Dr. Nauert began his career as a clinical physical therapist and served as a regional manager for a publicly traded multidisciplinary rehabilitation agency for 12 years. He has masters degrees in health-fitness management and healthcare administration and a doctoral degree from The University of Texas at Austin focused on health care informatics, health administration, health education and health policy. His research efforts included the area of telehealth with a specialty in disease management.

APA Reference
Nauert PhD, R. (2018). Increased Risk of Mental Illness if Sibling Hospitalized for Same Disorder. Psych Central. Retrieved on November 23, 2020, from
Scientifically Reviewed
Last updated: 8 Aug 2018 (Originally: 22 Sep 2016)
Last reviewed: By a member of our scientific advisory board on 8 Aug 2018
Published on Psych All rights reserved.