New study finds income-related inequalities impact mental health

Due to the recent economic crisis, an increase of health inequalities between socio-economic groups has been noticed in both developed and developing countries.

The World Health Organization, the World Bank and the United Nations Development Programme have all reported these inequalities and emphasized its importance and made this issue a priority.

There is evidence that such inequalities not only affect general health, but have a particular impact on mental health.

A new study, published in World Psychiatry, the official journal of the World Psychiatric Association (WPA), examined the data of the Korea National Health and Nutrition Examination Survey (KHANES), for the period between 1998 and 2007. The aim of the study was to measure income-related inequalities in depression, suicidal ideation and suicide attempts in South Korea and to trace their changes over a 10-year period (1998-2007).

The study data was obtained from a representative sample of the South Korean population through face-to-face interviews, gathering information about socio-economic status, health condition, and health behaviour (e.g. exercise, smoking, alcohol consumption). Information on depression and suicidal behaviour was obtained through self-report of whether the respondents had (a) been diagnosed with depression, (b) had ever felt like dying in the past 12 months, and (c) had ever attempted suicides in the past 12 months.

This study shows that the three psychopathologies (depression, suicidal ideation and suicide attempts) were more highly concentrated in lower income groups across years. This inequality observed was more pronounced in recent years, especially for suicide attempt. This means that the lowest income groups have the highest risk of depression, suicidal ideation and suicidal attempt.

Moreover, during this period, the suicide rate rose dramatically from an average of 13.0 per 100,000 to 26.0. This is the highest rate among countries belonging to the Organization for Economic Cooperation and Development (OECD). This may reflect an acute response to the economic crisis in the late 1990s.

This study showed clear existence of significant pro-rich inequalities in the prevalence of depression, suicidal ideation and suicide attempts. These inequalities have doubled over the past 10 years, in parallel to the widening income inequalities following the economic crisis.