Addressing data needs crucial for improving infant, child and youth mental health and substance-related harms in Aotearoa New Zealand: key design and ethical considerations for future research

Over the past two decades, public awareness and advocacy regarding mental health, mental illness and substance use–related harms (including addiction) have increased dramatically. There is growing pressure on governments and institutions to address these critical issues. In Aotearoa New Zealand, key policy and legislative documents set strategy and requirements: Kia Manawanui: Long-term pathway to mental wellbeing summarises the policy priorities and vision to transform the mental health and addiction system with a focus on prevention, promotion, early intervention and effective treatment and support. The Pae Ora (Healthy Futures) Act 2022 commits to the principle of setting mental health in parity with physical health.

Achieving these goals requires robust and comprehensive population data on the prevalence and impact of mental ill health and substance use–related harms. Such data are essential for determining where and to whom investments should be targeted. Additionally, robust epidemiological data support the design and implementation of preventative public health policies and programmes aimed at reducing risk factors and enhancing protective factors. Currently, Aotearoa New Zealand lacks these comprehensive data, particularly for infants and children.^1,2

Given that most mental health conditions and problematic substance use develop during childhood and adolescence,³ good data on the prevalence among, drivers of and experiences of infants, children and young people (ICY) are crucial. Even before the global pandemic, there were growing concerns about the influence of climate change, global unrest and the financial crisis, and social media, the internet and cyberbullying, alongside growing school pressures, on the mental health of ICY.^4,5 Indicators of greater levels of self-reported psychological distress among young people, at least in English-speaking high-income nations, are well documented.^6,7 This includes increasing numbers of young people reporting high levels of distress and symptoms of anxiety, depression and suicidality in Aotearoa New Zealand.⁸ Further to this, recent international epidemiological studies estimate that at any given time an average of one in eight children and young people are experiencing mental health conditions, which impact functioning. Many would benefit from support and services, but less than half are accessing support.⁹

Indigenous and minoritised ICY (e.g., ethnic minorities, sexual minorities, gender minorities, refugees and migrants and disabled ICY) are continuing to experience high levels of discrimination and issues related to structural violence, colonisation and intergenerational trauma and conflict, as well as inequitable rates of distress and lack of access to appropriate care.^10–14 Structural factors, including racism and discrimination, are inextricably linked to the likelihood of developing any mental health condition or problematic substance use. Therefore, contextual factors must be integral to future population-based studies as part of developing a better understanding of, and preventative response to, the mental health and substance use experiences of ICY in Aotearoa New Zealand.

Taking stock—the current state of data

To bring together knowledge on existing data and to identify gaps and future opportunities, national mental health and addiction workforce agencies—Te Pou, Le Va and Whāraurau—convened a rōpū (group) comprising diverse experts and partnered with researchers at The University of Auckland to undertake a scoping review focussing on the ICY population. From this review it was clear that while we have some data, most of the current research focusses on mid-to-late adolescents and covers a limited number of mental health conditions and some aspects of substance use, with a focus on youth in mainstream education settings.²

The review identifies that longitudinal studies, including Growing Up in New Zealand and the Pacific Islands Families Study, provide important information about the developmental pathways and causal factors for the onset and progression of mental health conditions and problematic substance use, following a cohort of people from birth to old age. However, these studies are not designed to provide representative estimates of population prevalence because they use smaller, geographically specific, purposeful samples, in contrast to the large, random sampling required for prevalence studies.

Aotearoa New Zealand also has repeated cross-sectional surveys, such as the New Zealand Health Survey (NZHS), and the General Social Survey (GSS). These provide limited but useful data to estimate prevalence of mental health symptoms for ICY and substance use for youth, and changes over time. The NZHS also collects information on some specific contextual factors such as sleep, screen time and child discipline. Periodically, the NZHS includes an additional mental health and problematic substance use module. While this provides greater insights than are available in the standard annual NZHS data, it is still limited in scope. For example, there are no questions on patterns of problematic eating, or psychosis symptoms.¹⁵ Also, the samples of children and young people are too small, limiting further sub-group analysis, e.g., by gender or ethnic group.² This means these data can tell us next to nothing about priority groups. While the NZHS provides estimates of the population rates of children and young people diagnosed with attention-deficit/hyperactivity disorder (ADHD) and autism, these data are based on people seeking help, accessing it and receiving a diagnosis. An upwards trend does not necessarily indicate increasing prevalence; it could mean increasing help seeking.

The Youth2000 series has provided the most comprehensive, national-level overview of youth (13–18 years) mental health and substance use, and, like the NZHS and GSS, the repeated nature of this survey allows for meaningful comparison over time. These studies cover a range of topics, including mental health, use of substances and contextual factors, and have included participants from diverse school settings, including wharekura (secondary schools where the medium of instruction is the Māori language), alternative education, Y-NEETS (young people who are not in education, employment and training) and teen parent units. They have also provided evidence related to priority groups, including young people in the care of Oranga Tamariki, young people from different ethnic groups, such as Māori, Pacific and Asian, young people with disabilities and those who identify as LGBTQIA+.^10–14 The scope of the studies does not include infants and children, and hence they cannot provide a comprehensive understanding of ICY mental health and substance use. The most recent survey from Youth2000 was in 2019, pre-COVID—hence, newer data are important. There is no funding secured for further surveys in this Youth2000 series. The Ministry of Social Development’s What about Me? survey asked questions about mental health and substance use among young people, but the questions and sample were not comparable with Youth2000 nor international surveys, so trends and population-level prevalence were unclear. The Ministry of Social Development is planning a new youth survey that will have some population-level mental health and substance use indicators included, although at the time of writing these do not provide a high level of detail.

Aotearoa New Zealand lacks epidemiological studies with a dedicated focus on mental health, substance use and addiction for children and young people. Many existing surveys, due to having a broader scope and therefore limitations on the number of items that can be asked, use brief self-report screening tools. For mental health these screening tools include the Strengths and Difficulties Questionnaire, Reynolds Adolescent Depression Screening: Short Form, Kessler-10 and Kessler-6. While such measurement tools are useful to capture potential need, and symptoms indicative of distress at the population level, they are unable to provide clinical estimates of the prevalence of mental health conditions, problematic substance use, neurodiversity, the context in which these symptoms are experienced (the possible drivers) and the impact on the person, whānau, education and communities.¹⁶ Furthermore, screening tools like Kessler are not commonly used in secondary mental health and addiction services, so there is a dissonance between research and clinical measures.

Datasets drawn from clinical samples also have major limitations as they are likely to significantly under-estimate the true extent of concerns, as most people who need mental health and addiction services do not receive them due to limitations of service delivery and inequitable access to care.² Similarly, questions on substance use rarely go beyond prevalence of use of common substances, and often do not explore associated harms. Questions on other addictive behaviours (e.g., gambling) are similarly limited. Studies outside of population-based and clinical studies are crucial to plan and invest in mental health and addiction support and services.

Of huge concern is that very few measurement tools used to understand mental health conditions and problematic substance use have been culturally validated in Aotearoa New Zealand.² There is an urgent need for Indigenous-determined measures. Research validating Indigenous measures is multilayered, requiring a combination of culturally meaningful, clinically relevant measures with careful analysis considering Indigenous contexts and worldviews.¹⁷

Other indicators of the changing mental health status of ICY can be gathered from administrative data, including hospitalisations with a primary coding as a mental health or behavioural condition, as well as data on waitlists. A strength of administrative data is inclusion of ICY aged between 0–19 years. Trends show the average number of hospitalisations for child and youth mental health or behavioural concerns have almost doubled over the last 10 years.¹⁸ However, administrative data are based on access to hospitalisation (e.g., does not count primary care presentations or those who cannot get help), therefore significantly under-counting population and clinical need. It is well recognised that Indigenous and minoritised groups do not equitably access mental health care based on a range of barriers including financial or transport barriers, wait times and stigma.^19–21 These datasets are thus inherently biased towards those willing and able to access support and services.¹⁶ So, while these service access and waitlist data provide valuable information, they are limited and cannot provide an accurate understanding about the types and magnitude of need for infants, children and young people.

The case for better surveillance and monitoring

In contrast to the existing studies and datasets, well-designed, dedicated population-based mental health and addiction studies can provide an accurate assessment of the scale and nature of mental health conditions and problematic substance use in the community and unmet need, and better understand drivers and the role of contextual factors.²² It is important that future population-based mental health and addiction studies focus on populations regularly left out (e.g., individuals living with disability, chronic illness, young children), or incorrectly represented, like Indigenous and minoritised groups, and groups in youth justice. In addition, sample sizes need to be sufficient to enable the analysis of sub-groups, e.g., disabled children, Māori tamariki (children) or children living in rural areas.^10,23 This type and level of epidemiological information is a crucial part of effective mental health and addiction policy and planning. The knowledge generated supports effective commissioning of preventative, as well as treatment-based, supports and services.⁵ Prevalence studies can help answer questions such as:

• What are the contexts (individual, social and political) in which we observe a higher or lower prevalence of mental health conditions and substance-related harm on children and young people?
• How many children and young people, for example, have ADHD, autistic spectrum disorder or obsessive-compulsive disorders?
• Of these children and young people, how many are accessing support and how many are not? Who are the populations, and where are needs the greatest?

Mental health–specific ICY population-based studies establish a baseline measure from which to track progress, changes over time and impact of investments made. Correlations between changes in contextual factors (e.g., parenting and school factors) and mental health outcomes can also be examined if contextual data are collected consistently.¹⁰ Repeat cross-sectional data also allow an exploration of the drivers of mental health and substance use trends and can provide knowledge to inform approaches to prevention and early intervention, potentially delaying the progression of worsening health conditions.²⁴

Other countries have invested in a repeated programme of child and adolescent mental health and addiction studies. For example, Australia is now on their third national child and adolescent mental health survey. The first took place in 1998, the second in 2014 and the third is about to commence.²⁵ The large-scale, repeated nature of this research provides ongoing evidence on the nature and extent of mental health conditions and has informed targeted investment in youth mental health programmes, such as the roll out of the headspace National Youth Mental Health Foundation.

Future opportunities

The last Aotearoa New Zealand mental health survey, Te Rau Hinengaro,²⁶ was undertaken 20 years ago. This was a high-quality, comprehensive and rigorous study; however, it only included those aged 16 years and above. Another epidemiological study specific to mental health and substance use is well overdue.

Aotearoa New Zealand can extend its knowledge of mental health conditions, addiction and substance-related harm for ICY and support the generation of data that uplift and support the mental health and wellbeing of ICY. We believe that future studies can achieve this by intentional consideration of the following:

1.       That this research is non-stigmatising, shifts away from a deficit-based narrative and informs action that harness the strengths of communities.

2.       Who is included in the studies and the settings in which they take place.

3.       How mental health conditions and substance-related harm are understood by the communities and measured, including key contextual factors.

1. Non-stigmatising strengths-based approaches that identify protective, community-based factors

Future research can be conducted in a way that does not contribute to stigma, discrimination and deficit-based narratives. Intentional and thoughtful procurement of the research, its design and implementation are needed to align with Indigenous worldviews, give priority to minoritised voices and uphold the values and perspectives of people with lived experience. Research conducted in this way can seek to change the narrative upon which policies are developed and services delivered. While it is important to make a distinction between transient emotional experiences such as mental distress and mental health conditions, which are longer lasting and impact on functionality, we believe this reporting can be done in a non-stigmatising, strengths-based way. The Youth19 survey series, among others, offers one such example.²⁷

We believe that future epidemiological studies focussed on mental health, addiction and substance-related harm could utilise the Consolidated criteria for strengthening the reporting of health research involving indigenous peoples (CONSIDER) statement.²⁸ The CONSIDER statement provides a checklist to optimise the advancement of hauora Māori, adopt a partnership approach across researchers and communities impacted and guide all aspects of the research governance, design, data collection, data analysis and dissemination.

Indigenous and lived experience–led research demonstrates methods that uplift and empower,²⁹ rather than perpetuate deficits and disempower narratives and statistics.

2. Who is included and the settings for research with ICY

Considering “who is included” means prioritising groups who are often under-represented and misrepresented in research and current data. Priority groups for future research are those communities we know are disproportionately impacted, including LGBTQIA+, Māori, Pacific and Asian ICY, refugees and migrants, ICY with disabilities, children involved with Oranga Tamariki and the youth justice system, those not engaged in education or work, those without secure housing, those living in small towns, remote or rural areas and those with low prevalence conditions, including first-episode psychosis.^2,10

Relatedly, consideration must be given to the settings in which data collection take place. Many of the large-scale studies regularly conduct surveys in mainstream school settings—thus, information about ICY not in mainstream education is sparse. Similarly, information about young people in tertiary education (e.g., university or polytechnics) or the workforce (including apprentice programmes) and infants and children in early learning education settings or home settings is very limited. The B4 School Check may also provide an opportunity for measuring the mental health of 4-year-olds, and support the collection of a nationally representative sample. This will require careful consideration at the design stage to find strategies to safely include samples from these population groups.

Future research must also focus on including diverse age groups in ICY. We advocate for a greater understanding of infant mental health and substance-related harms on infant wellbeing (e.g., in utero exposure to tobacco, alcohol or other drugs; exposure to second-hand smoke).

3. Exploring use of a new set of measures

Careful consideration needs to be given to what measurement tools are used to quantify the prevalence of mental health conditions and understand substance-related harm. Our recent scoping review² highlights the myriad of measures available that are used both internationally and within Aotearoa New Zealand.³⁰ Of great concern is that very few of these measurement tools have been culturally validated in Aotearoa New Zealand. Investing in the development of measurement tools, alongside cultural validation of some of these internationally developed tools, will help to ensure that they accurately capture the unique experiences faced by ICY in Aotearoa New Zealand.

It is equally important to understand and seek evidence related to positive measures of mental health and broader wellbeing, identifying the strengths of individuals, families and communities and exploring factors that uplift and improve mental health and wellbeing. These measures can provide crucial insights into what the services and support systems should offer and inform policy and other population-based interventions; for instance, developing measures that are holistic, whānau-centred and culturally grounded,²³ and aligned with Māori and Pacific worldviews, such as Te Whare Tapa Whā, Māori youth–specific model Te Tapatoru, the Tongan Fonua model and the Fonofale model.^31–33 Similarly, the Integrated Tree Model, a therapeutic framework developed by Asian Family Services, can be used for Asian and other ethnic communities.³⁴ He Piki Raukura²⁹ is a measurement tool developed to understand and assess development of Māori children within Kaupapa Māori early years education, but potentially could be used in a wider community sample. Flower of Two Soils is a measurement tool designed primarily for screening for ADHD, depression and conduct issues using dimensional measures and was found to have adequate evidence for reliability and validity with Indigenous young people in North America.³⁵ We are not advocating for different measures for different populations; rather, we are highlighting that there is a range of culturally grounded measures that could be brought into large-scale population surveys as part of a standard set of questions for all participants.

Ellison-Loschmann et al.²³ propose an approach to advance mental health and addiction research in Aotearoa New Zealand, by adopting a whānau-based study rather than individual-based population surveys. While more complicated than individual-based studies, they argue that whānau-based studies are feasible to conduct.²³ They also identify existing whānau-based mental health measures, such as the Whānau Ora assessment tool.³⁶ This would include the measurement of contextual factors for promotion, prevention and early intervention, also allowing an understanding of what factors are important to maximise whānau wellbeing and resilience. The importance of measuring the relationship between whānau and health and bringing whānau perspectives into assessment and support plans is not new. Durie and Kingi³⁷ in their report to the Ministry of Health offer a framework for measuring Māori mental health outcomes, with whānau perspectives and relationships integral to all measures. For ICY, this is likely to include, but will not be limited to, measuring family and whānau support, intergenerational experiences of inclusion, school connectedness, school environments, social and peer support, the role of social media, sleep, physical activity and nutrition.²²

Conclusions

Demand for mental health and addiction support and services is increasing in Aotearoa New Zealand, as in many other nations. There have been investment and service developments to help address this; however, there is a lack of ICY population–based data to understand where investments are most required and what are the effects of these investments. It is important to institute regular quality research to understand needs, unmet needs and changes over time, alongside the role of ecological and contextual factors. Aotearoa New Zealand has not conducted a comprehensive mental health and addiction study in 20 years, and no such study has ever been conducted for those under 16. To inform future service delivery and evidence-based policy, accurate, up-to-date data are urgently required. Addressing unmet and inequitable mental health and addiction needs presents a critical opportunity to improve outcomes for children, young people and their whānau.

Language and terminology

Mental health challenges—a strengths-based term preferred by people with lived experience that describes experiences from symptoms through to meeting diagnostic criteria for a mental health condition. This term also encompasses the experience of mental distress.

Mental distress (also known as psychological distress)—an emotional state that is usually transient and often occurs in response to stressors or life events. Commonly, people experience non-specific symptoms such as thoughts they find troubling, anxious feelings, low mood and disrupted sleep. These experiences may impact on daily routines and relationships. Mental distress ranges in intensity and impact. Many people with a significant degree of distress may not meet criteria for a diagnosable mental health condition.³⁸

Mental health conditions—a term used instead of mental disorders to describe when people meet specific diagnostic criteria. The distinction between mental distress and mental health conditions is not always easy to make, especially in children and young people. To be termed a “mental health condition”, according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, Text Revision (DSM-5-TR), a person’s symptoms need to be present for a specific length of time and be severe enough to limit their functioning on a daily basis. As stated above, mental distress is usually transient.³⁸

Problematic substance use—patterns of substance use that negatively impact people’s lives, including those that do not meet diagnostic criteria for substance use disorders. Substance use disorder may sometimes be used when specifically referring to people who meet diagnostic criteria.

Substance-related harm—any form of harm arising from substance use to the person using and/or to their whānau or communities.