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