Although it’s unknown what causes bipolar disorder, researchers believe they’re one step closer to finding why some children are at high risk of the mental condition.

In a small study, scientists at The University of Texas at Houston, identified several genes linked to stress and bipolar disorder, also known as manic depression.

Read: What Causes Bipolar Disorder? Aside From Genes, These Are The Things Most Likely To Increase Your Risk

“We’ve known that children of patients with bipolar disorder have a higher risk of developing the illness, but the biological mechanisms are largely unknown,” said study author Gabriel R. Fries, in a news release. “By analyzing the blood of children of controls and comparing it to children of bipolar patients, we identified several genes or markers that can explain the increased risk.”

In their paper, published in Translational Psychiatry, the authors write the mechanisms were previously unknown because past studies have primarily included chronically ill adults and not high-risk children without the illness.

The researchers analyzed blood from 18 children and adolescents that were separated into three groups: bipolar patients, unaffected children of bipolar parents, and children with parents with no history of bipolar disorder or any other psychiatric disorders.

Compared to children with parents of no history of mental health conditions, bipolar patients and unaffected children of bipolar parents had genetic changes in their blood that can influence how the body responds to stress.

Read: Bipolar Disorder Facts Vs. Myths: What People Living With Manic Depression Want You To Know

“We know from clinical studies of behavior and the environment that when children are chronically exposed to stressors, they are at a higher risk of developing bipolar disorder,” said Fries. “Bipolar parents may struggle because of their disease, leading to higher environmental stress. Their children, because of the genetic markers they have, could be more vulnerable to stress.”

The authors note larger studies need to be conducted to validate their findings.

Bipolar disorder is a serious brain illness that causes unexplained mood changes. Happier changes in mood are known as “manic episodes,” whereas changes with feelings of sadness are called “depressive episodes.” Symptoms vary in children and adults. When bipolar children or teens experience a manic episode they may have a short temper, talk fast about many things, engage in risky behavior, and have trouble sleeping but not feel tired. During a depressive episode, bipolar children and teens may feel worthless, have little energy, sleep too little or too much, and contemplate suicide.

Although you can develop the disorder at any age, it primarily develops in late teen or early adult years, according to the National Institute of Mental Health. Diagnosis of the disorder involves a doctor asking the child’s parents questions about his or her behavior, mood, sleeping patterns, and family history of medical problems, such as depression. If diagnosed, the doctor will offer a range of treatments, including medication and therapy.

See also: Bipolar Disorder: Signs And Symptoms Of The Manic-Depressive Mental Illness

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