The primary means of treating major mental illness remains psychotropic-based, whether alone or in combination with psychotherapy. Despite an ever-growing number of medication options, however, outcomes remain significantly suboptimal. In the landmark Sequenced Treatment Alternatives to Relieve Depression (STAR*D) study, only 37% achieved remission with first-line therapy with a selective serotonin reuptake inhibitor (SSRI), whereas 16.3% withdrew completely from treatment due to drug intolerance. In the Clinical Antipsychotic Trails of Intervention Effectiveness (CATIE), over 74% eventually discontinued study medication either because of lack of efficacy or tolerability. And in the Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) trial, up to 75% patients experienced symptoms relapse over the course of follow-up.