Differentiating ‘clinical’ and ‘non‐clinical’ depression

Objective There has been increasing concern about extensions to the definition of ‘clinical’ depression, but little evident investigation as to how clinical and non‐clinical depressive states might best be differentiated. This review considers the potential of many candidate symptom and non‐symptom parameters. Method We overview representative concerns and theories about the nature of psychiatric disorders before reviewing the potential utility of candidate parameters for differentiating clinical and non‐clinical depressive states. Results While we detail limitations to all candidate parameters designed to distinguish between clinical and non‐clinical depression, their actual utility may only be able to be judged by empirical testing across appropriate comparison groups. Conclusion We argue for initial comparisons being made between prototypically defined categorical (i.e. psychotic, melancholic and bipolar) depressive disease states and residual non‐melancholic clinical depressive states, before considering how each of those two clinical subsets might differ from non‐clinical depressive mood states.