Table 4.

Studies on UM assessing response to lithium prophylaxis.

Author	Findings	Conclusion (response to lithium prophylaxis)
Nurnberger et al. (1979) [18]	Response to lithium prophylaxis similar in patients with UM and BD hospitalized for depression; however, lithium is less effective in BD patients never hospitalized for depression.	UM < classical bipolar disorder
Yazici et al. (2002) [23]	Response to lithium prophylaxis similar in patients with UM and BD while using good, moderate, and poor response modes; however, when using responders and nonresponders as response mode, the UM group had significantly fewer responders than the BD.	UM < classical BD