Lasting Relationships Good for Mental Health

Megan Brooks

January 06, 2011

January 6, 2010 — Individuals in long-term relationships are less likely to be depressed, to think about or attempt suicide, or to abuse alcohol or drugs, a new study shows. Further, it doesn't seem to matter whether couples are married or merely living together.

The finding that longer relationship duration was associated with lower rates of mental health problems is "consistent with previous research showing that partner relationships have a protective effect on mental health, so we were not surprised by that," first study author Sheree J. Gibb, PhD, from University of Otago, Christchurch, New Zealand, told Medscape Medical News.

Dr. Sheree J. Gibb

"However, we were surprised to find that the protective effects of partner relationships on mental health were similar for legal and de-facto marriages, because this contrasts with previous research, which has suggested that the benefits of de-facto marriages are less than those of legal marriages," she said.

The findings are published in the January issue of the British Journal of Psychiatry. They stem from the Christchurch Health and Development Study, a longitudinal study of a birth cohort of 1265 individuals born in Christchurch in 1977 and followed to the age of 30 years.

As part of the study, at the ages of 25 and 30 years, participants were asked about their relationships in the past 12 months and about any mental health problems they may have had.

With the exception of anxiety disorders, increased time spent in a steady relationship was significantly associated with decreasing rates of depression, suicidal ideation or attempt, alcohol or illicit drug abuse or dependence, and total number of mental health problems, the researchers say.

For example, 15.6% of people who were not in a relationship and 20.8% of those in relationships for less than 2 years had depressive symptoms. However, the rate was only 11.5% in those in a relationship for 2 to 4 year and 10.0% in those in a relationship for more than 5 years. The difference was highly significant at P < .0005.

Similarly, the rate of alcohol abuse or dependence was 16.0% among those not in a relationship and 15.8% in those in relationships less than 2 years running. However, the rate was only 6.3% for those in relationships lasting 2 to 4 years and 6.2% for those in relationships lasting more than 5 years (P < .0001).

In the unadjusted analysis, people in relationships lasting 5 years or longer had overall rates of mental health problems that were roughly 56% of the rates of those people not in relationships. The protective effect of being in a long-term relationship held up in analyses adjusting for key covariates, including family background and previous mental health problems.

"Interestingly," Dr. Gibb said, "the legal status of the relationship did not make a difference. In other words, it was the length of the relationship that had a positive effect on people’s mental health — and it did not matter if the couple was married or cohabiting.

"This is a contrast to previous studies, which have reported lower rates of mental health problems among people in legal marriages than in cohabiting relationships," she said. However, many of those studies did not control for relationship duration, she added.

The fact that the birth cohort involved individuals from New Zealand, where living together without being married is common, is a limitation of the study. "It is not clear to what extent the results of the current study will generalize to different cohorts of individuals born in different places and different time periods," the study authors write.

Despite these limitations, the "study suggests that people who are at high risk of developing mental health problems may benefit from efforts to improve the stability and duration of their partner relationships, such as improved access to relationship counselling services," said Dr. Gibb.

The study was funded by the Health Research Council of New Zealand, the National Child Health Research Foundation, the Canterbury Medical Research Foundation, and the New Zealand Lottery Grants Board. The study authors have disclosed no relevant financial relationships.

Br J Psychiatry. 2011;198:24-30.