Marriage is known to be associated with improved mental health, but little research has examined whether the duration of a cohabiting relationship is associated with mental health.

To examine the associations between relationship duration and mental health problems in a birth cohort of 30-year-olds.

Associations between relationship duration and mental health were examined using a generalised estimating equation approach. Associations were adjusted for covariates, including prior mental health problems.

Longer relationship duration was significantly associated with lower rates of depression, suicidal behaviour and substance abuse/dependence, even after adjustment for covariates. In most cases the associations did not vary with gender. Legal relationship status (legally or de facto married) was not significantly related to mental health once due allowance was made for relationship duration.

Increasing relationship duration, but not legal relationship status, has a protective effect on mental health for men and women.

Psychiatric disorders are common during young adulthood and comorbidity is frequent. Individual psychiatric disorders have been shown to be associated with negative economic and educational outcomes, but few studies have addressed the relationship between the total extent of psychiatric disorder and life outcomes.

To examine whether the extent of common psychiatric disorder between ages 18 and 25 is associated with negative economic and educational outcomes at age 30, before and after controlling for confounding factors.

Participants were 987 individuals from the Christchurch Health and Development Study, a longitudinal study of a birth cohort of individuals born in Christchurch, New Zealand, in 1977 and followed to age 30. Linear and logistic regression models were used to examine the associations between psychiatric disorder from age 18 to 25 and workforce participation, income and living standards, and educational achievement at age 30, before and after adjustment for confounding factors.

There were significant associations between the extent of psychiatric disorder reported between ages 18 and 25 and all of the outcome measures (all P<0.05). After adjustment for confounding factors, the associations between psychiatric disorder and workforce participation, income and living standards remained significant (all P<0.05), but the associations between psychiatric disorder and educational achievement were not significant (all P>0.10).

After due allowance had been made for a range of confounding factors, psychiatric disorder between ages 18 and 25 was associated with reduced workforce participation, lower income and lower economic living standards at age 30.

Self-harm and suicidal behaviour are common reasons for emergency department presentation. Those who present with self-harm have an elevated risk of further suicidal behaviour and death.

To examine whether a postcard intervention reduces self-harm re-presentations in individuals presenting to the emergency department.

Randomised controlled trial conducted in Christchurch, New Zealand. The intervention consisted of six postcards mailed during the 12 months following an index emergency department attendance for self-harm. Outcome measures were the proportion of participants re-presenting with self-harm and the number of re-presentations for self-harm in the 12 months following the initial presentation.

After adjustment for prior self-harm, there were no significant differences between the control and intervention groups in the proportion of participants re-presenting with self-harm or in the total number of re-presentations for self-harm.

The postcard intervention did not reduce further self-harm. Together with previous results this finding suggests that the postcard intervention may be effective only for selected subgroups.