The clinical term “depression” has long been considered to result from an imbalance in serotonin, norepinephrine, and dopamine neurotransmitters. In addition to monoamine oxidase inhibitors (MAOIs), serotonin-norepinephrine reuptake inhibitors (SNRIs), tricyclic anti-depressants, and compounds that target norepinephrine and dopamine levels, selective serotonin reuptake inhibitors (SSRIs) increased as a consequence of the "chemical imbalance" idea. These sustances were promoted as 80-90% effective against depression and associated disorders in the early 1990s.
