As a new psych resident, I'd agree with this. The diagnostic system is not biologically based. It does at least offer a common language for mental health provid

As a new psych resident, I'd agree with this. The diagnostic system is not biologically based. It does at least offer a common language for mental health provides to speak, so that if one person calls something schizophrenia then other mental health providers will be on the same page about what that means. Personally, I'm very excited about direct neuromodulation technologies such as transcranial magnetic stimulation. These tools not only allow us to manipulate neural circuits, but to also test experimentally whether certain circuits causally contribute to a psychiatric phenotype of interest. As a treatment modality, they're incredibly safe and virtually have no side effects. Given that chemical receptors on neurons are so widely distributed, I doubt that a chemical substance can ever alter neural circuitry precisely enough to cure certain kinds of circuit dysfunctions. There's also starting to be exciting studies using brain imaging (e.g. fMRI) to tease apart the heterogeneity within conventional diagnostic categories and devise the inklings of biologically-based dimensional criteria.