Psychiatric morbidity and subsequent divorce: a couple-level register-based study in Finland.

PURPOSE: Studies that assess the role of mental health for the risk of divorce are scarce and mostly rely on individual-level data, although divorce is a couple-level phenomenon. Using data on couples, we examine the effects of both spouses' psychiatric morbidity on the risk of divorce, and whether socio-demographic factors affect these associations.

METHODS: We followed 96,222 Finnish married couples for 6 years using register-based data on both spouses and their household. New incidence of psychiatric morbidity and subsequent divorce was identified from dates of prescription medication purchases and hospital admissions, and dates of registered divorce. Socio-demographic factors were measured annually for both spouses and their household. The effect of incident psychiatric morbidity on divorce risk was analyzed using Cox regression.

RESULTS: Psychiatric morbidity in men increased the age-adjusted risk of divorce more than twofold and in women nearly twofold. The risk of divorce was particularly pronounced immediately after new incidence of psychiatric morbidity, before settling to a persistently high level. Psychiatric morbidity in both spouses increased the risk of divorce almost threefold. Adjustment for socio-economic factors had little effect on these associations.

CONCLUSIONS: Psychiatric morbidity is a persistent risk factor of divorce. The risk is larger when both spouses experience psychiatric morbidity compared to only one spouse. The findings are consistent with the idea that poor relationship quality and dissatisfaction in couples suffering from mental health problems have long-term consequences for marital stability. Treatment of psychiatric morbidity should not focus only on the individual but on couple-level dynamics.