Trends in psychological distress: analysis of NZ health survey data (2011–2023)

Introduction

Mental health disorders represent one of the leading causes of disability worldwide, with a growing global burden across all age groups. Although these conditions affect people across all demographics, certain populations carry a disproportionate share of this burden. Notably, Indigenous peoples in colonised nations, women, adolescents, and those living in socioeconomically deprived environments experience significantly higher rates of mental health challenges.^1–3 In Aotearoa New Zealand (NZ), Māori and Pacific peoples consistently report higher psychological distress than the general population, reflecting poorer overall health outcomes for these people as well as those living in material deprivation.^4–6

Women are particularly affected, experiencing approximately twice the rate of depression and anxiety compared to men, but young men have particular vulnerabilities where loneliness with unhelpful attitudes to both masculinity and mental health increase suicidality.^7,8 Youth, defined by the WHO as individuals aged 15–24 years, are another high-risk group. Epidemiological studies show that the majority of lifetime mental illnesses emerge before the age of 25 years.⁹ Furthermore, there appears to be a cumulative effect whereby causes combine to worsen outcomes.¹⁰ These early-onset conditions include anxiety disorders, mood disorders, and psychotic disorders. Early intervention is critical, as untreated mental health conditions during this developmental period can have lifelong consequences on education, employment, and social functioning.

Recent global trends among youth are particularly concerning. Depression, anxiety, and suicidal ideation have increased significantly in the past decade, with adolescent depression rates rising from 24 to 37% between 2011 and 2020.¹¹ Suicide rates in individuals aged 10–24 years in the U.S. increased from 6.8 to 10.6 per 100,000 between 2007 and 2017.¹² Similar patterns have been observed in NZ. Drivers of this trend include increased loneliness, cyberbullying, unrealistic social comparisons through social media, precarious employment, financial stress, and climate anxiety.^13–16 These compounding stressors are especially pronounced in young women.

In NZ, general practitioners (GPs) provide the majority of mental health care, managing mild to moderate conditions and serving as a gateway to specialist services. About 30% of GP consults have a mental health component.¹⁷ However, the primary care sector is under considerable strain. GP shortages, especially in rural and high-needs urban areas, are reducing access and undermining continuity of care.¹⁸ Workforce burnout, underfunding, and episodic care models limit the capacity of GPs to provide comprehensive mental health support.¹⁹ Against this backdrop, it is critical to understand population-level trends in psychological distress to inform health policy and service design.

Methods

This study analysed publicly available data from the New Zealand Health Survey (NZHS), an annual, nationally representative survey that collects information on various health indicators, including mental health. Each year, approximately 14,000 individuals aged 15 years and older are surveyed using stratified multistage sampling to ensure demographic and regional representation.²⁰ Psychological distress is measured using the Kessler Psychological Distress Scale (K10), a widely validated 10-item instrument that assesses symptoms of anxiety and depression over the previous 4 weeks that has also been validated in Māori and Pacifica populations.²¹ A score of 12 or more is classified as high or very high psychological distress (HVHPD).

Data from 2011 to 2023 were extracted from the NZHS online data explorer and processed in Microsoft Excel. The dataset was disaggregated by age group, gender, ethnicity (Māori, Pacific, and Other), and socioeconomic deprivation measured by the NZ Deprivation Index (NZDep), which divides the population into quintiles. Quintile 5 represents the most deprived 20% of the population. Subgroup data were analysed to examine trends over time.

Results

The prevalence of HVHPD in NZ increased markedly between 2011 and 2023. The national average rose by 2.5 times over this 12-year period. From 2011 to 2023, females aged 15–24 years had significantly higher rates of psychological distress than males of the same age group, with a mean difference of 9.05 percentage points (P < 0.001). Six percent of females aged 15–24 years reported high or very high psychological distress, yet by 2023, the rate was 30%. Regression analysis showed that the rate of increase was significantly steeper in females aged 15–24 years than males (P < 0.001), as demonstrated in Fig. 1.

Fig. 1.

HVHPD by age and gender.

Analysis revealed a statistically significant difference in psychological distress by ethnicity over the 2011–2023 period (P < 0.001). Distress is not distributed independently of ethnicity; Māori and Pacific peoples experiencing substantially higher estimated rates than other ethnic groups as shown in Fig. 2.

Fig. 2.

HVHPD by ethnicity.

Year-by-year chi-square tests confirmed that psychological distress was significantly associated with socioeconomic deprivation in every year from 2011 to 2023 (all P values were <0.001), with consistently higher distress in more deprived quintiles (Fig. 3).

Fig. 3.

HVHPD by quintile.

Discussion

These results reveal a sustained increase in psychological distress in NZ, particularly among young women, Māori, Pacific peoples, and individuals living in poverty. This trend places enormous pressure on primary care mental health services, which are already struggling with workforce shortages and structural limitations.

The increase among young women mirrors global data but is particularly sharp in New Zealand. The intersection of gender, age, and socioeconomic stressors – such as precarious employment, housing unaffordability, and digital influences – creates a uniquely vulnerable context. Social media use has been linked to poorer mental health outcomes in young women, particularly those with low self-esteem or a history of trauma.²² Meanwhile, systemic issues such as rising education costs and the climate crisis further undermine their psychological resilience.^23,24

The persistent disparities in distress experienced by Māori and Pacific peoples reflect structural inequities embedded in the healthcare system and broader society. These populations have endured intergenerational trauma, systemic racism, and inadequate access to culturally appropriate mental health services.²⁵ The underutilisation of Indigenous health models such as Te Whare Tapa Whā and Pacific frameworks such as the Fonofale Model limits the effectiveness of care.²⁶

Socioeconomic deprivation remains one of the strongest predictors of HVHPD. As the cost of living rises, particularly in urban centres, those in lower-income brackets experience compounding stressors. Poverty exacerbates mental illness and limits access to services, creating a cycle of disadvantage.²⁷ Current primary care funding models often disincentivise long-term relational care, making it difficult for vulnerable patients to establish therapeutic continuity with their providers. There is an urgent need to fund extended consults and interdisciplinary models that include mental health nurses, counsellors, and peer workers within general practice settings.

Workforce challenges are a key barrier. General practices across NZ face staffing shortages, especially in rural areas where recruitment and retention are difficult. Many practices rely on short-term locum doctors, which undermines continuity of care – a crucial factor in effective mental health treatment. Primary care must also evolve to meet the mental health needs of diverse populations. This includes not only improving access but also ensuring cultural safety. There is a strong case for expanding kaupapa Māori mental health services and community-led Pacific initiatives, which offer holistic and identity-affirming approaches. These services, however, require sustainable funding and workforce development pathways.

Conclusion

The rise in psychological distress across vulnerable demographic groups in NZ – those aged between 15 and 24 years, young women, Māori, Pacific peoples, and those experiencing socioeconomic deprivation – signals a growing mental health crisis. Without funding and structural reform to address social determinants of mental health as well as supporting culturally responsive relational care, the current trajectory of mental health inequities and service gaps will only worsen.