Bupropion  an antidepressant of the aminoketone class and a non-nicotine aid to smoking cessation  is chemically unrelated to tricyclic  tetracyclic  selective serotonin re-uptake inhibitor  or other known antidepressant agents Compared to classical tricyclic antidepressants  Bupropion is a relatively weak inhibitor of the neuronal uptake of norepinephrine  serotonin  and dopamine