How expanding legal marriage access affects mental health

Mental Health Effects of Marriage Policy: Evidence from Linked Administrative Data in New Zealand

['FUNDING_R01'] · VANDERBILT UNIVERSITY · NIH-11507237

This project looks at whether allowing more people to marry in New Zealand changed rates of anxiety, depression, self-harm, and substance-related problems among vulnerable groups.

Quick facts

Phase['FUNDING_R01']
Study typeNih_funding
SexAll
SponsorVANDERBILT UNIVERSITY (nih funded)
Locations1 site (Nashville, UNITED STATES)
Trial IDNIH-11507237 on ClinicalTrials.gov

What this research studies

From a patient's point of view, researchers use nationwide linked administrative data in New Zealand to compare mental health and health-care use before and after the 2013 expansion of marriage access. They examine prescriptions, mental health and substance-use treatment referrals, hospital records, and marriage records to track outcomes like anxiety, depression, deliberate self-harm, substance abuse, and overdoses. The team applies difference-in-differences and event-study methods to compare groups whose eligibility to marry changed with those who were unaffected. They also look for differences in effects across ages, ethnic groups, and other vulnerable subgroups.

Who could benefit from this research

Good fit: People who lived in New Zealand around the 2013 marriage law change whose ability to marry changed—particularly couples and vulnerable individuals with anxiety, depression, or histories of self-harm—are the population represented in this work.

Not a fit: People living outside New Zealand or whose marital rights were unchanged are unlikely to be affected by the findings and would not directly benefit from this specific study.

Why it matters

Potential benefit: If expanded marriage access is tied to better mental health, findings could inform laws and services to reduce anxiety, depression, and self-harm in vulnerable populations.

How similar studies have performed: Previous research has linked legal recognition of relationships to better mental-health outcomes for some groups, but causal evidence is mixed, so this large administrative-data, quasi-experimental approach is stronger and partly novel.

Where this research is happening

Nashville, UNITED STATES

Researchers

About this research

  1. This is an active NIH-funded research project — typically early-stage science, not a clinical trial accepting patient enrollment.
  2. Some NIH-funded labs run parallel clinical studies or seek volunteers for related work. To check, contact the principal investigator or institution listed above.
  3. For full project details, budget, and progress reports, visit the official NIH RePORTER page below.

View on NIH RePORTER →

Last reviewed 2026-05-15 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.