Some commonly used antidepressants have been linked to increase certain patients’ risks of developing mania or bipolar disorder, a large study suggests.
The strongest link was for depressed patients prescribed Effexor (Venlafaxine) or antidepressants called serotonin reuptake inhibitors (SSRIs), the British study found. SSRIs include Citalopram (Celexa), Escitalopram (Lexapro), Fluoxetine (Prozac), Paroxetine (Paxil), and Sertraline (Zoloft).
However, many patients who developed mania or bipolar symptoms likely had underlying bipolar disorder or a predisposition because of family history or other factors, the researchers believe.
Understanding Bipolar Disorder:
“Bipolar disorder, also known as manic-depressive illness, is a brain disorder that causes unusual shifts in mood, energy, activity levels, and the ability to carry out daily tasks. Symptoms of bipolar disorder can be severe. They are different from the normal ups and downs that everyone goes through from time to time. Bipolar disorder symptoms can result in damaged relationships, poor job or school performance, and even suicide. But bipolar disorder can be treated, and people with this illness can lead full and productive lives.
Bipolar disorder often appears in the late teens or early adult years. At least half of all cases start before age 25. Some people have their first symptoms during childhood, while others may develop symptoms late in life.
Bipolar disorder is not easy to spot when it starts. Some people suffer for years before they are properly diagnosed and treated. Like diabetes or heart disease, bipolar disorder is a long-term illness that must be carefully managed throughout your life.
Bipolar disorder tends to run in families. Some research has suggested that people with certain genes are more likely to develop bipolar disorder than others. Children with a parent or sibling who has bipolar disorder are much more likely to develop the illness, compared with children who do not have a family history of bipolar disorder. However, most children with a family history of bipolar disorder will not develop the illness.
Technological advances are improving genetic research on bipolar disorder. One example is the launch of the Bipolar Disorder Phenome Database, funded in part by NIMH. Using the database, scientists will be able to link visible signs of the disorder with the genes that may influence them.
Scientists are also studying illnesses with similar symptoms such as depression and schizophrenia to identify genetic differences that may increase a person’s risk for developing bipolar disorder. Finding these genetic “hotspots” may also help explain how environmental factors can increase a person’s risk.
But genes are not the only risk factor for bipolar disorder. Studies of identical twins have shown that the twin of a person with bipolar illness does not always develop the disorder, despite the fact that identical twins share all of the same genes. Research suggests that factors besides genes are also at work. It is likely that many different genes and environmental factors are involved. However, scientists do not yet fully understand how these factors interact to cause bipolar disorder.”
The study was also observational and, “we did not demonstrate a causal association between antidepressants and mania/bipolar disorder,” said lead researcher Dr. Rashmi Patel, of the department of psychosis studies at King’s College London’s Institute of Psychiatry, Psychology, and Neuroscience.
The findings still highlight the need to consider risk factors for bipolar disorder in people treated for major depression, Patel said.
These include a family history of bipolar disorder, a prior depressive episode with psychotic symptoms, depression at a young age, or depression that doesn’t respond to treatment, he said.
“If you are taking antidepressants and are concerned that you might be experiencing adverse effects, it is important to seek medical advice to review your medication and to not stop your treatment suddenly, as this may result in withdrawal symptoms,” Patel said.
Major depression is one of the most common mental disorders in the United States, According to the U.S. Centers for Disease Control and Prevention, about one in 10 Americans aged 12 years and over takes antidepressant medication.
For the study, Patel and colleagues studied the medical records of more than 21,000 adults treated for major depression in London between 2006 and 2013.
SSRIs were the most commonly prescribed antidepressants (35.5 percent), the researchers said.
Effexor, a dual-acting drug used to treat both depression and anxiety, was taken by less than 6 percent of patients. Fewer than 10 percent took mirtazapine (Remeron) and fewer than 5 percent used tricyclics (Elavil).
Nearly 1,000 patients were diagnosed with bipolar disorder or mania during the follow-up period of roughly four years.
“We found that antidepressants were widely prescribed and associated with a small increased risk in developing mania and bipolar disorder,” said Patel.
This association was particularly strong for SSRIs and Effexor as these drugs seemed to increase the risk 34 percent to 35 percent, the researchers said.
The peak age for manic or bipolar episodes amongst patients taking antidepressants was 26 to 35, the researchers reported.
According to the U.S. National Institute of Mental Health, bipolar disorder, also known as manic-depressive illness, causes unusual shifts in mood, energy, activity levels, and the ability to carry out everyday tasks.
Authors noted that the individuals in this study with undiagnosed bipolar disorder may be more susceptible to treatment when in the depressive stage of the illness. That could certainly help explain the link between antidepressants and later bipolar behavior.
The report was published Dec. 15 in the online journal BMJ Open.
Dr. Ami Baxi, interim director of inpatient and emergency psychiatry at Lenox Hill Hospital in New York City, said, “As the prevalence of depression increases, more and more antidepressants are being prescribed and patients often ask about the risks associated with these drugs.”
However, in this case it is difficult to say that these medications cause bipolar disorder especially since several risk factors related to underlying bipolar disorder were not assessed in this study, said Baxi, who was not involved with the study.
This research indicates a correlation of antidepressant treatment and manic episodes without reviewing preexisting risk factors of developing bipolar disorder, she explained.
“For patients who are concerned about this risk of conversion to bipolar disorder, the results of this study should encourage a discussion with your doctor regarding the benefits of the antidepressant and your risk factors for developing bipolar disorder before making any changes in medications,” she said.
Patel agreed and said that better ways of identifying depression patients who may be at risk of developing bipolar disorder need to be developed.
The National Institute of Mental Health