Conditions: Bipolar Disorder
Keywords: Bipolar disorder Cognitive dysfunction Memantine NMDA antagonist
Allocation: RANDOMIZED | Intervention model: PARALLEL
Enrollment: 72
Healthy volunteers: no

Brief summary:
The purpose of this study is to see whether memantine improves memory function in participants with bipolar disorder who have minimal symptoms. Secondary analyses will test the role of memantine in improving residual mood symptoms (depression and mania) in participants with bipolar disorder.

We hypothesize that in participants with bipolar disorder who have minimal symptoms memantine will be effective in improving cognitive functions, as measured by the difference in neuropsychological test scores at the beginning and at the end of the trial.

Detailed description:
A large proportion of participants with bipolar disorder experience significant cognitive dysfunction, even when euthymic, after adequate treatment. The cognitive deficits in asymptomatic patients with bipolar disorder are very important for the participant's psychosocial function. In this population, cognitive deficits have been associated with poor psychosocial functioning, such as inability to hold a job. Memantine is a glutamate N-methyl-D-aspartate (NMDA) receptor antagonist which has shown efficacy in cognitive dysfunction due to moderate to severe Alzheimer disease.

Demonstrating the role of memantine in reducing cognitive dysfunction in minimally symptomatic participants with bipolar disorder promises to provide important clinical information, which could lead to improvements in well-being and functional status for large populations of participants with bipolar disorder.

Arms:
arm 1: Placebo-matching memantine 5 mg tablet once per day for 1 week; dose increase if tolerated to placebo-matching memantine 5 mg twice a day, in the morning and the evening in Week 2; dose increase if tolerated to placebo-matching memantine 5 mg in the morning and placebo-matching memantine 10 mg in the evening in Week 3; dose increase if tolerated to placebo-matching memantine 10 mg twice a day, in the morning and the evening Weeks 4 to 12. arm 2: Re-purposed Alzheimer's drug to treat cognitive dysfunction associated with bipolar disorder. Memantine 5 mg tablet once per day for 1 week; dose increase if tolerated to memantine 5 mg twice a day, in the morning and the evening in Week 2; dose increase if tolerated to memantine 5 mg in the morning and memantine 10 mg in the evening in Week 3; dose increase if tolerated to memantine 10 mg twice a day, in the morning and the evening Weeks 4 to 12.

Interventions: intervention 1: Memantine intervention 2: Placebo
Intervention descriptions: intervention 1: Week 0: 5 mg memantine or placebo once a day (q.d.) Week 1: 5 mg memantine or placebo twice a day (b.i.d.) Week 2-3: 5 mg memantine or placebo once in the morning (q.a.m.)/10 mg once in the evening (q.p.m.) Week 4-12: 10mg Memantine or placebo b.i.d. intervention 2: Inactive comparator. Placebo-matching memantine tablet.

Protocol document: