Who would likely benefit most from taking lithium carbonate?

A) Zara, who is near death from starving herself.
B) Jonathan, who swings from mania to thoughts of suicide.
C) Josué, who has hallucinations and delusions.
D) Barbara, who experiences excessive worry and anxiety.

Lithium carbonate is commonly used as a mood stabilizer and is specifically effective in treating bipolar disorder. Jonathan's symptoms of mood swings and suicidal thoughts are indicative of bipolar disorder, making him likely to benefit the most from taking lithium carbonate. Zara is likely experiencing anorexia nervosa, a disorder that is not typically treated with lithium. Josué's symptoms of hallucinations and delusions are indicative of a psychotic disorder, which can be treated with antipsychotics but not necessarily lithium. Barbara's excessive worry and anxiety may be treated with medications such as antidepressants, anti-anxiety medications, or beta-blockers, but not specifically lithium.