What is Lithium primarily used to treat?

Lithium is primarily used to treat Manic-Depressive (bipolar) Disorder because it is a mood stabilizer that effectively reduces the intensity and frequency of manic episodes and helps prevent the recurrence of both manic and depressive episodes. The use of lithium in this context is based on its ability to modulate neurotransmitter pathways in the brain, which assists in stabilizing mood swings associated with bipolar disorder.

In the context of other disorders listed, while there are specific medications for disorders like Attention Deficit Hyperactivity Disorder, Generalized Anxiety Disorder, and Major Depressive Disorder, lithium is not typically utilized as a first-line treatment for these conditions. Each of those disorders has distinct treatment protocols that may involve other classes of medications, not including lithium as a standard treatment option. Therefore, the primary indication for lithium remains its effectiveness in managing bipolar disorder specifically.