Treatment nonadherence (TN) adversely affects patient outcomes, particularly among those with mental health disorders (MHDs) (Alcalá et al., 2022; Levin et al., 2020; Velligan et al., 2017). According to the National Alliance on Mental Illness (2025), 23% of the U.S. population experienced MHDs in 2024, with depression being the most common. The suicide risk was 56% higher with moderate-prognosis cancers, 5 times higher with poor-prognosis cancers, and as much as 16 times higher with severe MHDs (Kahn et al., 2023).
Edie Anyieni (Mon,) studied this question.