In my paper I briefly discuss an evolution in the treatment of depression over thousands of years but the roots of modern psychopharmacology can be traced back to the end of the 19th century when lithium was used for inmates in insane asylums. It was not until 1952 the antimycobacterial agent iproniazid, a treatment for tuberculosis, was discovered to have psychoactive properties. Patients given the drug exhibited a change in mood. They were typically more cheerful and physically active. It was shown that the drug slowed the enzymatic breakdown of neurochemicals or monamines( serotonin, dopamine, and norepinephrine). It would take ten years before the first antidepressant drugs would be used on patients. Throughout the 60s and 70s scientists would be fueled by "the serotonin hypothesis" a more specific description of what is essentially thought of as a chemical imbalance. The first SSRIs (Selective Serotonin Reuptake Inhibitors) were developed in the early 70s and started being clinically prescribed by the 80s but with many unwanted side effects such as sedation or nausea. Due to technical advances in the field of neuroscience a better understanding was reached of just how these psychoactive drugs interacted with receptors on neurons and how such interactions changed neural functioning. As a result improved antidepressants were developed with less side effects. Here is a video of a psychiatrist describing antidepressants are still evolving today. Below it is a not so flattering look at the history of the SSRI drug Paxil.