The role of depression in unnatural death:A case-based retrospective study

Background: Depression affects the life of millions around the globe and perhaps also the manner of death. This study examined the role of depression in specific causes of unnatural death and whether alcohol and substance use affect this relationship, in one locality in Scotland.Methods: The research used a retrospective case-based study approach to analyse 168 cases, quantifying data reported in mortuary files to allow for quantitative statistical analysis of associations and differences amongst the variables.Results: A diagnosis of depression was associated with a higher likelihood of unnatural death due to suicide, drugs or homicide. A diagnosis of substance abuse was associated with a diagnosis of depression and with an increased likelihood of death due to suicide or drugs. A diagnosis of alcohol abuse was associated with a reduced likelihood of a diagnosis of depression but was associated with an increased likelihood of suicide.Limitations: This study relied on a small sample from one locality in Scotland which limited the ability to generalise the results and the retrospective case-based design also limited the potential for checking data accuracy or to consider temporal relationships, which limited the ability to interpret causality.Conclusions: This study found that there was a relationship between depression and unnatural death, which was mediated by alcohol and substance use. The importance of this study lies within the recognition of these relationships which identified the complexities of these relationships but suggested that some unnatural deaths within this population could be prevented.