Personalised medicine has finally been featured in psychiatric journals, but psychiatrists have mainly focused on the promise of using disease mechanisms to personalise treatment. Psychiatric disorders such as schizophrenia and depression are not diseases, in the medical sense, and are probably more like syndromes. Instead of spending much time and effort focusing on the mechanisms of diseases that may instead be syndromes, the author believes that psychiatrists should (1) learn more about personalising prescription via drug mechanisms, a pharmacological approach to personalised medicine; and (2) reconsider prior attempts by traditional clinical psychopharmacologists to use sophisticated clinical approaches that try to subdivide psychiatric syndromes into groups that may be more homogenous for treatment response.