Over the last decades, many specialists have worked tirelessly to improve the lives of people affected by mental health problems. The topic has also received increasing political and funding priority. However, despite global efforts, progress in understanding, predicting, and treating mental health problems remain disappointing. I discuss two barriers to progress. The first is diagnostic literalism, the tendency to take mental health diagnoses for more than they are. The second is reductionism, aiming to understand mental health problems by reducing them to a few (often biological) elements. Both views result from, and in turn reinforce the problematic premise that mental health diagnoses cut nature at her joints. Conceptualizing mental disorders as complex, biopsychosocial systems is a crucial shift. It provides us with new lenses through which we can study mental health disorders, and also has the potential to provide new levers, similar to other disciplines such as biology, medicine, and ecology where understanding systems has provided novel tools for intervention.