Can norepinephrine treat depression?

Kind of. Increasing norepinephrine in the brain is often a component of medications designed to treat depression such as bupropion, venlafaxine, and duloxetine as well as to a weaker degree in some ssris. Combinations of medications which influence serotonin, norepinephrine, and Dopamine are often the most effective in more moderate to severe depression. Norepinephrine alone may not be sufficient.
YES!! The older medication class of the tricyclics was the option available for treating depression . These primarily inhibited the re uptake of norepinephrine. There was also some serotonin activity. The newer meds since Prozac focuses on serotonin and then there are combinations for serotonin and nor-epinephrine re uptake inhibition like cymbalta, effexor, and pristiq (desvenlafaxine).