Mental health problems, especially among youth, have exploded together with major expansions in mental health awareness efforts. The theory of concept creep, or when harm-related concepts broaden their meanings over time, describes this phenomenon but is agnostic about the mechanisms behind the harms. We suggest that this lack of clarity is due to a fragmented literature with proposed mechanisms spread across adjacent fields. Across theories and explanatory frameworks of concept creep, nocebo effects, prevalence inflation, and illness self-labeling, we identify three common mechanisms through which mental health awareness may unintentionally cause harm. These include (a) lowering the threshold for what counts as a mental disorder, (b) increasing attention to internal states and pathologizing ambiguous experiences, and (c) reinforcing negative expectations and identities over time. We describe these shared mechanisms, propose a path forward for research priorities, broaden the evidence for harms from mental health awareness, and offer options for effective multifaceted interventions to reduce them