Federal and state cooperation necessary but not sufficient for effective regional mental health systems: insights from systems modelling and simulation.

For more than a decade, suicide rates in Australia have shown no improvement despite significant investment in reforms to support regionally driven initiatives. Further recommended reforms by the Productivity Commission call for Federal and State and Territory Government funding for mental health to be pooled and new Regional Commissioning Authorities established to take responsibility for efficient and effective allocation of 'taxpayer money.' This study explores the sufficiency of this recommendation in preventing ongoing policy resistance. A system dynamics model of pathways between psychological distress, the mental health care system, suicidal behaviour and their drivers was developed, tested, and validated for a large, geographically diverse region of New South Wales; the Hunter New England and Central Coast Primary Health Network (PHN). Multi-objective optimisation was used to explore potential discordance in the best-performing programs and initiatives (simulated from 2021 to 2031) across mental health outcomes between the two state-governed Local Health Districts (LHDs) and the federally governed PHN. Impacts on suicide deaths, mental health-related emergency department presentations, and service disengagement were explored. A combination of family psychoeducation, post-attempt aftercare, and safety planning, and social connectedness programs minimises the number of suicides across the PHN and in the Hunter New England LHD (13.5% reduction; 95% interval, 12.3-14.9%), and performs well in the Central Coast LHD (14.8% reduction, 13.5-16.3%), suggesting that aligned strategic decision making between the PHN and LHDs would deliver substantial impacts on suicide. Results also highlighted a marked trade-off between minimising suicide deaths versus minimising service disengagement. This is explained in part by the additional demand placed on services of intensive suicide prevention programs leading to increases in service disengagement as wait times for specialist community based mental health services and dissatisfaction with quality of care increases. Competing priorities between the PHN and LHDs (each seeking to optimise the different outcomes they are responsible for) can undermine the optimal impact of investments for suicide prevention. Systems modelling provides essential regional decision analysis infrastructure to facilitate coordinated federal and state investments for optimal impacts.