Mental illness among concerned significant others to individuals with substance use problems: linking self-reported harm with adverse outcomes in registers

Research problem and specific questionsSubstance use such as alcohol consumption and illicit drug use are major public health concerns in Sweden and globally.

Substantial proportions of the population (4-15%) have also experienced harm from others’ substance use (HFOSU) in the previous year in Sweden. Family members are most affected, but friends and colleagues can also suffer.

Being a concerned significant other (CSO) to a person with substance use problems is commonly attached to experiences of stress and strain with an increased risk of mental illness.

However, there is a dearth of national and international research addressing the risk of mental health problems among CSOs. Existing studies are based on cross-sectional surveys or non-representative clinical samples.

The project aims to increase the understanding of mental health problems among adult CSOs in Sweden, and differences in mental health between groups of CSOs, by linking data from a general population survey with longitudinal register data from the same individuals.

This will, for the first time, show how self-reported HFOSU is connected to different types of mental illness over time based on an adult population sample.Data and methodParticipants from a large general population survey among adults in Sweden (n=11,043) on HFOSU will be linked with information on mental disorders from national health registries.

The participants´ mental health will be followed for the four years before and three years after they participated in the survey.

Changes in the outcomes over time will be estimated and compared between individuals experiencing HFOSU with those that do not experience such harm while accounting for relevant confounders.Societal relevance and utilizationImproving the situation for individuals suffering from HFOSU is one of the goals in the government´s strategy including alcohol and illicit drugs (Skr. 2021/22:213).

The project will provide new insights into the mental health impact of HFOSU in the population.

This knowledge is important for revealing the problematic situation for CSOs and the development of preventive measures aiming at reducing the suffering of HFOSU.Plan for project realizationThe project will be planned and implemented in collaboration with a reference group consisting of representatives from research, civil society and the healthcare sector.

The budget mainly covers the salary of the project leader and administrative costs for the data linkage.