Bupropion hydrochloride is an antidepressant medication that affects chemicals within the brain that nerves use to send messages to each other. (Forfivo XL is an extended release form of bupropion hydrochloride.) Chemical messengers are called neurotransmitters. Many experts believe that depression is caused by an imbalance among the amounts of neurotransmitters that are released. Nerves may recycle neurotransmitters by a process referred to as reuptake in which the released neurotransmitters are taken up and reused (released again) by the nerves. Bupropion works by inhibiting the reuptake of dopamine , serotonin , and norepinephrine by the nerves after they have been released, an action that results in more dopamine, serotonin, and norepinephrine to transmit messages to other nerves. Bupropion is unique and unlike other antidepressants in that its major effect is on dopamine, an effect that is not shared by the related selective serotonin reuptake inhibitors or SSRIs (for example, paroxetine [ Paxil ], fluoxetine [ Prozac ], sertraline [ Zoloft ]) or the tricyclic antidepressants or TCAs (for example, amitriptyline [ Elavil , Endep ], imipramine [ Tofranil ], desipramine [ Norpramin ]). The FDA approved Forfivo in December 1985.
Testosterone is significantly correlated with aggression and competitive behaviour and is directly facilitated by the latter. There are two theories on the role of testosterone in aggression and competition.  The first one is the challenge hypothesis which states that testosterone would increase during puberty thus facilitating reproductive and competitive behaviour which would include aggression.  Thus it is the challenge of competition among males of the species that facilitates aggression and violence.  Studies conducted have found direct correlation between testosterone and dominance especially among the most violent criminals in prison who had the highest testosterone levels.  The same research also found fathers (those outside competitive environments) had the lowest testosterone levels compared to other males.