Rapid and unequal decline in adolescent mental health and well-being 2012-2019: Findings from New Zealand cross-sectional surveys.

To investigate prevalence and trends in key mental health and well-being indicators among New Zealand secondary school students. Representative cross-sectional youth health surveys with 2-4% of the New Zealand secondary school population were conducted in 2001, 2007, 2012 and 2019 (total In 2019, 69.1% reported good well-being (95% confidence interval = [67.6, 70.6]; World Health Organization 5-item), 22.8% reported clinically significant depression symptoms (95% confidence interval = [21.4, 24.1]; Reynolds Adolescent Depression Scale-Short Form) and 41.8% reported possible anxiety symptoms (95% confidence interval = [40.5, 43.2]; Generalized Anxiety Disorder 2, adapted). Past-year prevalence of periods of low mood (38.3%, 95% confidence interval = [36.6, 40.1]), deliberate self-harm (24.1%, 95% confidence interval = [22.8, 25.4]), suicide thoughts (20.8%, 95% confidence interval = [19.2, 22.4]) and suicide attempts (6.3%, 95% confidence interval = [5.5, 7.0]) were observed. After relative stability from 2001 to 2012, there were large declines in mental health to 2019. The proportion reporting good well-being decreased (odds ratio 0.71, 95% confidence interval = [0.65, 0.78], Adolescent mental health needs are high in New Zealand and have increased sharply from 2012 among all demographic groups, especially females, Māori, Pacific and Asian students and those from high-deprivation neighbourhoods. Ethnic and socioeconomic disparities have widened.