In 1949, Australian psychiatrist John Cade discovered lithium seemed to be effective for bipolar patients who went through manic phases. The drug was later approved by the FDA in 1970 as a mood stabilizer, though not much work since or after really elucidated the mechanism of action of lithium.
“How lithium acts on the brain has been this great mystery of psychopharmacology,” said Joshua Meisel, researcher at the Massachusetts Institute of Technology and lead author of the study published in the journal of Current Biology. “There are hypotheses, but nothing’s been proven.”
Putting it together, the team concluded that lithium may stabilize moods by inhibiting certain neurons, which then blocks the activity of BPNT-1. In humans, when BPNT-1 is blocked, other chemical signals for dopamine, epinephrine, and norepinephrine are also dampened. “This is an important step in showing a neural function for BPNT-1. It’s the first study to show in a multicellular system that the BPNT-1 protein might be the target for lithium’s action,” said John York, biochemistry professor at the Vanderbilt University School of Medicine who was not involved in the research.
Most recently another results from another study identified another pathway by which lithium exerts its actions. A team of researchers from the National Institute of Standards and Technology (NIST) found that lithium associates with ATP - the body’s main “chemical fuel.” In particular, lithium had a strong affinity to form bimetallic complexes with magnesium and ATP (Mg-Li-ATP). The study was published in Biophysical Journal.
The National Institute of Mental Health estimates about 2.6 percent of Americans suffer from bipolar disorder. For these patients, lithium is still the first line of defense as specified by the American Psychiatric Association. But lithium doesn’t work on everyone, and every piece of research that decodes lithium’s mystery could be another step closer to more tailored, more effective treatments.
Additional sources: MIT press release, NIST.gov press release