Mental health, like physical health, represents an important resource for participating in politics. We bring new insights from six surveys from five different countries (Britain, Germany, the Netherlands, Switzerland, and the United States) that combine diversified questions on mental health problems and political participation. Unlike previous research on depression, we find only limited evidence for the Resource Hypothesis that mental health problems reduce political participation, except in the case of voting and only in some samples. Instead, we find mixed evidence that mental health problems and their comorbidity (experiencing multiple problems) are associated with increased political participation. Our study leads us to more questions than answers: are the measures available in public opinion surveys appropriate for the task? Do general survey samples adequately capture people with mental disorders? And is the assumption that poor mental health reduces political participation wrong?