A new international study led by researchers from University of British Columbia (UBC) and NIMHANS has found that treatment with modern antidepressants can help prevent patients with Bipolar I disorder from relapsing into a depressive episode.
“The findings, published in the New England Journal of Medicine on August 3, challenge current clinical practice guidelines, and could change how bipolar depression is managed globally,” said Y.C. Janardhan Reddy, head of the Department of Psychiatry and OCD Clinic at NIMHANS.
What is bipolar disorder?
Bipolar disorder, earlier known as manic-depressive disorder, is prevalent in about 1% of the population, and tends to be a lifelong illness. Bipolar disorder has two phases — depression and mania. “Patients can sometimes develop mania, and other times depression, in a cyclical fashion,” said Professor Reddy, who is the principal investigator of the study in India.
Professor Lakshmi Yatham from the UBC, who is a visiting professor at NIMHANS, is the global principal investigator of the study that has been supported by the Canadian Institutes of Health Research.
“Antidepressants are effective in treating depression and in preventing relapse of depression in ‘recurrent depressive disorder’, often called ‘unipolar depression’. However, depression also occurs in the context of bipolar disorder. While there is effective medication to treat and prevent acute mania, treatment and prevention of bipolar type of depression have been challenging, despite the advent of many medications recently,” Professor Reddy told The Hindu on August 3.
“Guidelines recommend discontinuation of antidepressant treatment eight weeks after remission of depression. However, results of this first global randomised clinical trial conducted at sites in Canada, India, and Korea involving 178 patients with bipolar disorder, demonstrate that extending adjunctive antidepressants up to 52 weeks may be beneficial in preventing relapse into depression compared to discontinuation after eight weeks of remission. A majority of the participants in this study were from India, mainly from NIMHANS,” he said.
Stating that bipolar depression can be severe and is often associated with high suicide risk, Dr Reddy said previous studies have shown that suicide attempts and suicide deaths are at least 18 times more common during depressive episodes compared to during manic episodes.
“There is a concern that antidepressants used to treat unipolar depression and other forms of depression may not only be ineffective in treating depression of the bipolar type but may even worsen the course of illness by precipitating mania. Nonetheless, globally and in India, bipolar depression is often treated with adjunctive antidepressants (anti-manic medications and antidepressants), but the duration of this therapy is widely debated due to a lack of evidence and concerns that antidepressants may induce mania,” he explained.
Findings of new study
“Our study found that continuation of antidepressant for 52 weeks, compared to eight weeks, was not statistically significant in preventing any mood episode (mania or depression). But a fine-grained analysis of data from six-week post-randomisation (till then both groups received an antidepressant) showed a significant benefit in continuing adjunctive antidepressant for 52 weeks in preventing relapse of any mood episode as well as a depressive episode. No difference was observed in the number of manic episodes,” he said.
“Stabilising patients and preventing relapses, particularly depressive relapses is critical. Our study has demonstrated that modern antidepressants may have a potential role in doing so,” said Dr Reddy.
“We hope future revisions of bipolar guidelines will incorporate the evidence from this study, and contribute to changes in clinical practice on how antidepressants will be used to manage patients with bipolar disorder, “ he added.