DSM IV cautions that individuals within any diagnostic group are heterogeneous: its categories are only intended as aids to clinical judgement. But it promotes an idea of specificity in diagnosis that is linked to a conception of specificity in underlying pathology. The broad categories of the start of the twentieth century – depression, schizophrenia, neurosis – are no longer adequate. Pathologies of mood, cognition, will, or affect are dissected at a different scale. The psychiatric gaze is no longer molar but molecular. And behind this molecular classification of disorders lies another image of the brain – that of contemporary neuroscience – and of therapeutic intervention – that of psychopharmacology.

Nikolas Rose, The Politics of Life Itself, Pg 199, Princeton university Press