Scenario (combination of interventions)
Mental health services growth	× 2	× 2	× 3	× 3	× 3	× 5	× 5	× 5
Direct access proportion	—	10%	—	20%	20%	—	50%	50%
Perceived need for services	—	—	—	—	+5%	—	—	+10%
Prevalence of moderate to very high psychological distress †
All people
Prevalence (baseline: 40.24%) ‡	39.52%	39.34%	39.48%	38.54%	38.45%	39.48%	37.95%	37.50%
Difference (percentage points)	–0.72	–0.90	–0.76	–1.70	–1.79	–0.76	–2.30	–2.74
People aged 15–24 years
Prevalence (baseline: 52.87%) ‡	52.45%	52.17%	52.48%	51.67%	51.45%	52.46%	51.39%	50.86%
Difference (percentage points)	–0.42	–0.70	–0.39	–1.20	–1.42	–0.41	–1.48	–2.01

^*Assumptions: extended Better Access (maximum twenty sessions per year) available until 31 December 2022; more rapid growth in specialised mental health services commences 1 January 2022; direct access and increase in perceived needs for mental health services commence 1 January 2024.

^†Kessler Psychological Distress Scale (K10) score of 16–50.

^‡The prevalence of moderate to very high psychological distress in New South Wales increased from 2013 (all ages, 27.2%; 16–24 years, 33.5%) to 2019 (all ages, 43.5%; 16–24 years, 63.5%). ¹⁹