A new study investigating the biological impact of marital dissolution suggests that a history of divorce does not accelerate physical changes in the brain associated with aging or dementia. Researchers analyzed brain scans from a racially and ethnically diverse group of older adults to look for signs of neurodegeneration. They found no robust link between having been divorced and the presence of Alzheimer’s disease markers or reductions in brain volume. These findings were published in Innovation in Aging.

The rising number of older adults globally has made understanding the causes of cognitive decline a priority for medical researchers. Scientists are increasingly looking beyond diet and exercise to understand how social and psychological experiences shape biology. Psychosocial stress is a primary area of interest in this field. Chronic stress can negatively impact the body, potentially increasing inflammation or hormonal imbalances that harm brain cells over time.

Divorce represents one of the most common and intense sources of psychosocial stress in the United States. Approximately 17 percent of adults over the age of 50 reported being divorced in 2023. The experience often involves not just the emotional pain of a relationship ending but also long-term economic strain and the loss of social standing. These secondary effects are often particularly harsh for women.

Previous research into how divorce affects the aging mind has produced conflicting results. Some past studies indicated that divorced or widowed individuals faced higher odds of developing dementia compared to married peers. Other inquiries found that ending a marriage might actually slow cognitive decline in some cases. Most of this prior work relied on memory tests rather than looking at the physical condition of the brain itself.

To address this gap, a team of researchers sought to determine if divorce leaves a physical imprint on brain structure. The study was led by Suhani Amin and Junxian Liu, who are affiliated with the Leonard Davis School of Gerontology at the University of Southern California. They collaborated with senior colleagues from Kaiser Permanente, the University of California, Davis, and Rush University.

The team hypothesized that the accumulated stress of divorce might correlate with worse brain health in later years. They specifically looked for reductions in brain size and the accumulation of harmful proteins. They also aimed to correct a limitation in previous studies that often focused only on White populations. This new analysis prioritized a cohort that included Asian, Black, Latino, and White participants.

The researchers utilized data from two major ongoing health studies. The first was the Kaiser Healthy Aging and Different Life Experiences (KHANDLE) cohort. The second was the Study of Healthy Aging in African Americans (STAR) cohort. Both groups consisted of long-term members of the Kaiser Permanente Northern California healthcare system.

Participants in these cohorts had previously completed detailed health surveys and were invited to undergo neuroimaging. The researchers identified 664 participants who had complete magnetic resonance imaging (MRI) data. They also analyzed a subset of 385 participants who underwent positron emission tomography (PET) scans. The average age of the participants at the time of their MRI scan was approximately 74 years old.

The primary variable the researchers examined was a history of divorce. They classified participants based on whether they answered yes to having a previous marriage end in divorce. They also included individuals who reported their current marital status as divorced. This approach allowed them to capture lifetime exposure to the event rather than just current status.

The MRI scans provided detailed images allowing the measurement of brain volumes. The team looked at the total size of the cerebrum and specific regions like the hippocampus. The hippocampus is a brain structure vital for learning and memory that often shrinks early in the course of Alzheimer’s disease. They also examined the lobes of the brain and the volume of gray matter and white matter.

In addition to volume, the MRI scans measured white matter hyperintensities. These are bright spots on a scan that indicate damage to the brain’s communication cables. High amounts of these hyperintensities are often associated with vascular problems and cognitive slowing.

The PET scans utilized a radioactive tracer to detect amyloid plaques. Amyloid beta is a sticky protein that clumps between nerve cells and is a hallmark characteristic of Alzheimer’s disease. The researchers calculated the density of these plaques to determine if a person crossed the threshold for amyloid positivity.

The statistical analysis accounted for various factors that could skew the results. The models adjusted for age, sex, race and ethnicity, and education level. They also controlled for whether the participant was born in the American South and whether their own parents had divorced.

The results showed that individuals with a history of divorce had slightly smaller volumes in the total cerebrum and hippocampus. They also displayed slightly greater volumes of white matter hyperintensities. However, these differences were small and not statistically significant. This means the calculations were not precise enough to rule out the possibility that the differences were due to random chance.

The PET scan analysis yielded similar results regarding Alzheimer’s pathology. There was no meaningful association between a history of divorce and the total burden of amyloid plaques. The likelihood of being classified as amyloid-positive was effectively the same for divorced and non-divorced participants.

The researchers performed several sensitivity analyses to ensure their findings were robust. They broke the data down by sex to see if men and women experienced different effects. Although the impact of divorce on brain volume seemed to trend in opposite directions for men and women in some brain regions, the confidence intervals overlapped. This suggests there is no strong evidence of a sex-specific difference in this sample.

They also checked if the definition of the sample population affected the outcome. They ran the numbers again excluding people who had never been married. They also adjusted for childhood socioeconomic status, looking at factors like parental education and financial stability. None of these adjustments altered the primary conclusion that divorce was not associated with brain changes.

There are several potential reasons why this study did not find a link between divorce and neurodegeneration. One possibility is that the stress of divorce acts more like an acute, short-term event rather than a chronic condition. Detectable changes in brain structure usually result from sustained exposure to adversity over many years. It is possible that for many people, the stress of divorce resolves before it causes permanent biological damage.

Another factor is the heterogeneity of the divorce experience. For some individuals, ending a marriage is a devastating source of trauma and financial ruin. For others, it is a relief that removes them from an unhealthy or unsafe environment. These opposing experiences might cancel each other out when analyzing a large group, leading to a null result.

The authors noted several limitations to their work. The study relied on a binary measure of whether a divorce occurred. They did not have data on the timing of the divorce or the reasons behind it. They also lacked information on the subjective level of stress the participants felt during the separation.

Future research could benefit from a more nuanced approach. Gathering data on the duration of the marriage and the economic aftermath of the split could provide clearer insights. Understanding the personal context of the divorce might help reveal specific subgroups of people who are more vulnerable to health consequences.

The study provides a reassuring perspective for the millions of older adults who have experienced marital dissolution. While divorce is undoubtedly a major life event, this research suggests it does not automatically dictate the biological health of the brain in late life. It underscores the resilience of the aging brain in the face of common social stressors.

The study, “The Association Between Divorce and Late-life Brain Health in a Racially and Ethnically Diverse Cohort of Older Adults,” was authored by Suhani Amin, Junxian Liu, Paola Gilsanz, Evan Fletcher, Charles DeCarli, Lisa L. Barnes, Rachel A. Whitmer, and Eleanor Hayes-Larson.

New research conducted in Finland highlights distinct patterns in relationship stability when comparing same-sex and opposite-sex unions. The findings indicate that while female couples experience the highest rates of divorce, the factors contributing to these breakups vary by gender composition. The study suggests that traditional gender norms regarding income and the specific challenges faced by immigrant men in host societies play substantial roles in these outcomes. This research was published in the journal Advances in Life Course Research.

Sociologists and demographers have previously observed that same-sex couples tend to dissolve their unions at higher rates than opposite-sex couples. This trend is particularly pronounced among female couples. Despite this established pattern, the specific reasons behind these disparities have remained largely unexplained. Theoretical models suggest that minority stress, which includes experiences of discrimination and stigma, likely destabilizes these relationships.

Other theories focus on the search for a partner. Finding the right spouse involves predicting future compatibility, a process that is inherently uncertain. This uncertainty is often higher regarding economic characteristics. Researchers wanted to understand if specific observable factors could account for the stability gap. The authors of the current study aimed to determine if nationality intermarriage, religious affiliation, education, or income dynamics could explain the differences in divorce risks.

“There was increasing interest in understanding how the intersections of several minority statuses (e.g., sexual minority and immigration background) shape divorce risks. Not much was known about this because there has been a lack of sufficiently large data to statistically address these types of questions,” said study author Elina Einiö, a lecturer at the Helsinki Institute for Demography and Population Health at the University of Helsinki.

The researchers utilized comprehensive register-based data from Statistics Finland. The dataset covered the entire population of individuals who entered a same-sex registered partnership or an opposite-sex marriage between March 2002 and February 2017. The observation window ended just before Finland implemented gender-neutral marriage laws, replacing the registered partnership system.

The final sample consisted of 3,780 same-sex couples and 339,401 opposite-sex couples. Among the same-sex unions, 37.2 percent were male couples and 62.8 percent were female couples. The researchers restricted the data to couples where at least one spouse lived in Finland at the time of registration and was born in the country. They tracked these couples until the end of 2021 to identify legal divorces.

The analysis employed Cox proportional hazards models to estimate divorce risks. The models controlled for variables such as the year of marriage, the age of both spouses, and the area of residence. The researchers also incorporated annual data on taxable income and religious affiliation based on church tax records.

The general findings revealed a clear hierarchy in divorce risk. Approximately 40 percent of female couples divorced within the first ten years of their legal union. This rate was significantly higher than the 24 percent observed for male couples. Opposite-sex couples had the lowest rate, with 21 percent divorcing within the same timeframe.

For female couples, the elevated risk persisted even after accounting for various socioeconomic factors. The researchers found that income and religious affiliation played only a modest role in explaining their higher divorce rates. The risk for female couples remained roughly double that of opposite-sex couples in the fully adjusted models. This suggests that unobserved factors, potentially including minority stress, continue to impact these relationships heavily.

The results for male couples told a different story. Their slightly higher risk of divorce was partly explained by higher rates of intermarriage and lower rates of religious affiliation. When researchers adjusted for these factors, the difference in divorce risk between male couples and opposite-sex couples became barely significant.

A major focus of the study was the impact of nationality intermarriage. The data showed that marriages involving a foreign-born husband and a native-born spouse were less stable. This pattern was consistent for both male couples and opposite-sex couples. It indicates that the specific experience of being an immigrant man in a host society may strain a marriage.

“It was surprising to see that intermarriage between a foreign-born husband and a native-born spouse destabilizes marriages, regardless of the latter spouse’s gender,” Einiö told PsyPost. “This suggests that there could be psychological distress stemming from being an immigrant man in a host society rather than distress resulting from gendered conflicts between a man and a wife due to different cultural understandings of gender roles.”

This destabilizing effect was not observed in female couples. Marriages between a foreign-born woman and a native-born woman did not show elevated divorce risks compared to couples where both women were native-born.

“Female same-sex couples had an elevated divorce risk, but this risk did not further increase if a native-born woman married a foreign-born wife,” Einiö said. “One of the reasons could be that when a native-born woman legalizes her relationship with another woman, it is often with someone of a relatively similar cultural background (e.g., a wife from another European country).”

Income dynamics provided further insight into how gender norms shape relationship stability. The study distinguished between the primary breadwinner and the secondary breadwinner. In opposite-sex couples, this usually aligned with the husband and wife, respectively. For same-sex couples, the researchers categorized earners based on age to allow for comparison.

High income for the primary breadwinner appeared to stabilize all marriages. This was true regardless of the gender composition of the couple. When the primary earner brought in more money, the risk of divorce decreased across the board.

However, the income of the secondary breadwinner had divergent effects. In opposite-sex marriages, a higher income for the secondary earner was associated with an increased risk of divorce. This aligns with theories regarding the “independence effect,” where financial independence may allow a wife to leave an unhappy marriage.

In contrast, a higher income for the secondary earner in same-sex marriages tended to stabilize the union. This was particularly evident for male couples. The data suggests that male couples benefit from greater income equality within the relationship. While income inequality often protected opposite-sex marriages, it appeared to be a risk factor for same-sex unions.

Religious affiliation also emerged as a significant factor. The study measured this by tracking membership in Finland’s national churches. Joint membership in a church was associated with lower divorce risks for all couple types. This may reflect shared values or the presence of social support from a religious community.

Dissimilarity in religious status was detrimental for some. When one partner was a church member and the other was not, divorce risk increased for same-sex couples. This effect was strongest for male couples. Such dissimilarity did not appear to impact the stability of opposite-sex couples.

The researchers discussed several theoretical implications of these findings. The persistence of high divorce rates among female couples supports the minority stress hypothesis. Women in same-sex relationships may face compounded stress from sexual minority status and gender-related societal expectations. They may also lack the institutional support often available to mixed-gender couples.

The findings regarding men suggest that deviations from cultural norms impact them differently. For immigrant men, the pressure of adapting to a host society appears to bleed into marital stability. For gay men, the lack of shared religious community or significant income disparities can weaken the relationship bond.

The study has some limitations inherent to the use of administrative data. The registers do not contain information on the psychological well-being of the participants. This prevents a direct measurement of relationship quality or specific stressors. The data relies on legal gender markers, which excludes non-binary identities. Additionally, religious affiliation was measured by church tax payment, which may not accurately reflect personal faith or spirituality.

The researchers note that the context of Finland is specific. The country is known for high gender equality but was relatively late among Nordic nations to adopt same-sex marriage laws. The transition from registered partnerships to marriage in 2017 may have altered the social landscape, though the study period largely covers the partnership era.

Future research is needed to see if these patterns hold in other countries. The authors specifically express interest in whether the destabilizing effect of intermarriage for men is consistent across different European nations. Understanding these nuances helps clarify how the intersection of gender, culture, and economic resources influences the longevity of modern relationships.

The study, “Divorce in same-sex and opposite-sex couples: The roles of intermarriage, religious affiliation, and income,” was authored by Elina Einiö and Maria Ponkilainen.