Memantine, a common drug used to treat Alzheimer’s disease, was found to improve cognitive dysfunction in bipolar disorder, according to new research presented at the 10th International Conference on Bipolar Disorders.
In a clinical trial, memantine helped improve cognitive deficits in bipolar patients who were in euthymia (a relatively stable mood state), compared to placebo.
“Subjects with bipolar disorder have significant cognitive and functional deficits, even when they are euthymic,” said lead author Dan Iosifescu, M.D., director of the Mood and Anxiety Disorders Program, Icahn School of Medicine at Mount Sinai, New York City.
“This is something that is not usually recognized, and it is important because it has a direct impact on the individual’s ability to function in real life, even when their symptoms of depression are somewhat controlled,” said Iosifescu.
Problems with attention, short-term memory, and executive functioning exist, but there is little understanding about what could help improve these deficits, he added.
“For a very long time, these cognitive deficits were interpreted as having some residual symptoms, depression or mania, and that these needed to be better controlled, perhaps with increased doses of mood stabilizers. But as it turns out, this is not the right answer, and a lot of people continue to have cognitive problems,” he said.
For the study, 72 euthymic bipolar patients (mean age of 47), were randomly assigned to receive memantine or placebo for 12 weeks. Fifty-five percent of the patients had type I bipolar disorder, and 45% had bipolar II disorder. All had reported cognitive deficits — problems with thinking, language, attention and memory.
At the end of the 12 weeks, all participants were given memantine for another 12 weeks. The doses were flexible and ranged from 5 to 20 mg per day.
The researchers found that in the first 12 weeks of the study, those who took memantine had significant improvements in spatial and working memory, verbal and episodic memory, as well as improved attention, language, and delayed memory, compared with patients receiving placebo.
However, there were no significant differences in social functioning between the placebo and memantine groups, Iosifescu said.
“We would have liked to hear that they were better able to find a job or that their interpersonal relationships got better, that their improvements in cognition translated into something useful, but this wasn’t the case. But perhaps we will see a benefit in the life functioning of these patients further down the line,” he said.
Memantine was well tolerated, and retention in the study was excellent, he added.
In the future, memantine may prove a helpful addition to cognitive training programs for people with bipolar disorder.
“If you can help people pay better attention and have better retention when they are trying to learn, they would improve their ability to participate successfully in cognitive remediation strategies,” said Iosifescu.