Need for mental health treatment is best represented not as a unitary construct but as a series of overlapping circles. The first circle is the level of disease burden, which can be measured as diagnoses, symptomatology, and functional burden. The second circle is availability of treatments, because need for treatment implies the existence of a therapy. The third is consumers' perspective on need, which may not agree with the first two measures. Finally, as examined by Messias' team, a clinician's judgment can add valuable contextual information. When these four definitions overlap, assessing need is easy. When they diverge, it is important to reconcile them through dialogue that allows balancing of competing priorities. Throughout the process, we must recognize the complexity of defining need in mental health and the reality that we may not always know it even when we think we see it.