Since memantine may not only inhibit overactivity of microglial cell, but also repair the
damaged neurons and neurogenesis through activation of astroglial cell and release of
neurotrophic factors, the investigators propose that the neurotrophic effect of memantine may
benefit neurodegenerative diseases including bipolar disorders (BP) and alcohol dependence.
In the current study, the investigator will investigate whether add-on memantine at a dose of
5 mg/day has a beneficial effect on BP comorbid with alcohol dependence.