Are Suicide Rates Related to the Psychiatrist Density? A Cross-National Study

Introduction Most suicide victims have a diagnosable psychiatric disorder. Treatment of psychiatric disorders should reduce the number of suicides. Higher psychiatrist-per-population ratio increases the opportunity for contact between the patient and psychiatrist. It is reasonable to hypothesize that the higher psychiatrist density (PD) is associated with lower suicide rates. The aim of this study is to examine the association between suicide rates and the PD in the European Union countries. These countries are economically and culturally connected and located on the same continent. This is an attempt to study a relatively homogenous sample. Methods Correlations were computed to examine relationships between age-standardized suicide rates in women and men, the PD, and the gross national income (GNI) per capita. Partial correlations were used to examine the relation between the PD and age-standardized suicide rates in women and men controlling for the GNI per capita. Results Higher suicide rates in women correlated with the higher PD. Controlling for the GNI per capita, the PD positively correlated with suicide rates both in women and in men. There was a trend toward a negative correlation between the GNI per capita and suicide rates in men. The PD was positively associated with the GNI per capita. Conclusion Probably, higher suicide rates directly and/or indirectly affect the decisions made by policy- and lawmakers regarding mental health services and how many psychiatrists need to be trained. The results of this study should be treated with caution because many confounding variables are not taken into account.

Higher psychiatrist-per-population ratio improves access, decreases waiting times, and increases the opportunity for contact between the patient and psychiatrist. Generally, an increase in the physician density tends to lead to physician-induced demand (10). People living in countries with greater psychiatrist density (PD) had a higher probability of seeing a psychiatrist.
The literature suggests that availability of good healthcare services may reduce suicide rates by allowing timely identification and appropriate treatment of psychiatric disorders, providing prompt and effective medical help including resuscitation to those who attempt suicide, allowing appropriate management of risk factors for suicides, and facilitating the implementation of national policies on mental health and suicide prevention (11).
It is reasonable to hypothesize that the higher PD is associated with lower suicide rates. To test this hypothesis, I performed an ecological cross-sectional study. I examined the association between suicide rates and the PD in the European Union countries. These countries are economically and culturally connected and located on the same continent. This is an attempt to study a relatively homogenous sample. Socioeconomic factors may influence suicide rates (12)(13)(14)(15). Therefore, I controlled for the gross national income (GNI) per capita.

MaTerials anD MeThODs
Information on age-standardized suicide rates in men and women, the PD, and the GNI per capita in the European Union countries was obtained from the WHO database, "Global Health Observatory Data Repository" ( Table 1) (16,17). The agestandardized suicide rate is a weighted average of the age-specific mortality rates per 100,000 persons, where the weights are the proportions of persons in the corresponding age groups of the WHO standard population (18). The 2012 WHO data on suicide rates were used (16).
The PD is the number of psychiatrists working in the mental health sector per 100,000 of the population (19). Psychiatrists working in mental health include psychiatrists employed in private and public mental health facilities as well as private practice. The most recent data available in the WHO database were used.

Sher
Suicide Rates and the Psychiatrist Density Frontiers in Public Health | www.frontiersin.org The GNI is the gross national income converted to international dollars using purchasing power parity rates (20). An international dollar has the same purchasing power over the GNI as a U.S. dollar has in the U.S. GNI is the sum of value added by all resident producers plus any product taxes (less subsidies) not included in the valuation of output plus net receipts of primary income (compensation of employees and property income) from abroad. The latest data available in the WHO databank were used.
Correlations were computed to examine relationships between age-standardized suicide rates in women and men, PD, and GNI. Partial correlations were used to examine the relation between PD and age-standardized suicide rates in women and men controlling for GNI.
The following method was used to create scattered plots of partial correlations (21): I created three linear regression models. SNI per capita was an independent variable in every model. In the first, the second, and the third models suicide rates in women, suicide rates in men, and the PD were dependent variables, respectively. I computed the residuals of suicide rates in women, suicide rates in men, and the PD. The partial correlation is equivalent to the correlation between the residuals of the linear regression.
The SPSS program (version 23) was used to perform statistical analysis.

resUlTs
The WHO have data on all 28 European Union countries included in the study: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, and United Kingdom ( Table 1). The mean female and male suicide rates, the PD, and the GNI in the European Union countries were 4.293 ± 1.992 and 18.429 ± 9.413 per 100,000 people per year, 11.883 ± 5.605 per 100,000 people, and $31,110 ± 10,374, respectively.
Higher suicide rates in women correlated with the higher PD (Table 2; Figure 1). Controlling for the GNI per capita, the PD positively correlated with suicide rates both in women and in men    Figures 2 and 3). There was a trend toward a negative correlation between the GNI per capita and suicide rates in men (Table 2; Figure 4). The PD was positively associated with the GNI per capita (Table 2; Figure 5).

DiscUssiOn suicide rates and Psychiatrist Density
This study suggests that higher suicide rates are associated with higher number of psychiatrists working in mental health per 100,000 people. This observation is consistent with previous reports, suggesting that the PD positively correlates with suicide rates (11,22,23). The most likely explanation for this association is that the higher suicide rates directly and/or indirectly affect the decisions made by policy-and lawmakers regarding mental health services and how many psychiatrists need to be trained. Indeed, there is very considerable evidence that suicide rates may affect national policies related to mental health and suicide prevention (24)(25)(26)(27)(28). Also, the registration of suicide cases may be better in countries with a higher PD and higher income (23). This may contribute to the observed association between suicide rates and PD. Additionally, there are the differences between countries with regard to suicide prevention and other mental health services related to the differences in psychiatric education and training (29). This factor may also play a role in the observed associations.

gni and suicide rates in Men
The presence of a trend toward a negative correlation between the GNI and suicide rates in men is consistent with observations that the economic factors, such as income, wealth, and employment status, may affect suicidality in men (13-15, 30, 31). For example, I have previously observed that per capita income is related to suicide rates in men but not in women: men in countries with lower per capita income commit suicide more frequently than men in countries with higher per capita income (15). Another example is a British study which found that each 10% increase in the number of unemployed men was significantly associated with a 1.4% increase in male suicides (31).

Psychiatrist Density and gni
This study shows that there is a higher PD in countries with the higher GNI per capita. This is an expected finding: countries with more resources have more physicians, including psychiatrists (11,22,23,32). Median mental health expenditures per capita around   the world are $1.63 with large variation among income groups, ranging from $0.20 in low-income countries to $44.84 in high-income countries (32). There is a strong positive correlation between mental health spending per capita and the GNI per capita (32).

limitations
The results of this study should be treated with caution because many confounding variables, such as cultural and religious differences between countries have not been taken into account. Also, the quality of training of psychiatrists is probably different in different countries. It is also important to note that the income in the European Union countries is higher than in many other countries. Therefore, the results of this study may not be generalizable to low-income countries.
cOnclUsiOn Both mental health services and socioeconomic improvements are needed to reduce suicide rates. Probably, psychiatric services prevent many suicides. Absence of suicide produces no data. It is difficult to notice successful suicide prevention. Future epidemiological, ecological, psychological, and neurobiological studies of suicidality are merited and may lead to the development of treatments which will reduce suicide rates.
aUThOr cOnTriBUTiOns LS has designed the study, conducted literature searches and statistical analysis, and wrote the manuscript. reFerences