Evidence across disciplines suggests that talk therapy is more curative than antidepressants for mild-to-moderate depression and anxiety. Yet, few patients use it. We develop a dynamic choice model to analyze patient demand for the treatment of depression and anxiety. The model incorporates myriad potential impediments to therapy use along with links between mental health improvements and earnings. The estimated model reveals that mental health improvements are valuable, directly through utility and indirectly through earnings. However, patient reluctance to use therapy is nearly impervious to reasonable counterfactual policies (e.g., lowering prices or removing other costs). Patient behavior might reflect stigma, biases in beliefs about the effectiveness of therapy, or a distaste for discussing personal or painful issues with a stranger. More broadly, the benefits of therapy estimated in randomized trials tell only half the story. If patients do not use treatments outside of an experimental setting—and we fail to understand why or how to get them to—estimated treatment effects cannot be leveraged.