(Drug) treatment-resistance can result from endogenous genetic factors which predict an individual’s ability to respond to one agent or another. In addition to informing drug selection, pharmacogenetic testing can identify those individuals with specific vulnerabilities to being drug treatment-resistant. Moreover, nutritional supplementation augments the potential benefits of psychotropic treatment. Fortunately, many individuals can experience clinical improvement with appropriate nutritional supplementation. Once again, we attempt to utilize available evidence to justify our decision-making in selecting such interventions