The goal of this clinical trial is to assess the safety and effects of a crystallized form of lithium, AL001, when compared to commonly used lithium carbonate in individuals diagnosed with bipolar I disorder. The main questions this study aims to answer are:
* How safe is AL001 when compared to lithium carbonate?
* How is AL001 broken down in the brain and body compared to lithium carbonate?
Participants will be asked to:
* Take both the study drug (AL001) and lithium carbonate each for a period of 14 days.
* Stay overnight at MGH's research unit for two separate 2-week periods.
* Participate in two separate 24 hour periods of multiple MRIs and blood draws.