That scenario is possible with medications that work by increasing synaptic levels of monoamines like serotonin, norepinephrine, and dopamine. (The fancy word for this is monoaminergic.)
‘Antidepressant’ is a clinical classification, not a pharmacological one. As such, this group includes medications with all sorts of different mechanisms. And lithium is almost in a class of its own in this regard. Researchers are still piecing together exactly how it works.
What they do know is that lithium is one of the strongest meds for dampening suicidal ideation and can be a savior for those in such mental crisis.
