serotonin and norepinephrinemethylphenidate norepinephrinedopamine and norepinephrineguanfacine norepinephrinebupropion norepinephrinenorepinephrine depressionnorepinephrine functiontyrosine norepinephrinenorepinephrine hormonecaffeine and norepinephrineashwagandha norepinephrineincrease norepinephrine