Medications focused on mental ill health include a range of drugs generally categorised as antipsychotic medications, antidepressants and anxiolytics. The differentiation does not describe the complete variance of mental health illness, but it does provide a framework from where an understanding of the biological circuitry of reward, motivation and stress can be gained. A full understanding of how and why mental health disorders occur is not yet achieved; indeed, it appears the same clinical symptom may be caused by multiple mechanisms. This means that manifestation of a particular symptom may have a different aetiology in different people. In this chapter, action potential and synapse function are discussed and applied to therapeutic drugs that impact on the central nervous system. Taking this process further, this chapter examines particular pathways in the brain associated with mental health illness and how modulating nerve communication in these pathways may improve a person’s mental health. As initially suggested, the three mental health conditions to be addressed in this chapter are schizophrenia, depression and anxiety. Drugs identified and discussed for these conditions may also be prescribed for other illnesses such as bipolar disorder.