Allergies and suicidal behaviors: a systematic literature review.

BACKGROUND

Allergies are among the most common chronic conditions. In addition to physical and social impacts, a number of studies have consistently linked allergies to poor psychological outcomes, including depression and anxiety.

OBJECTIVES

The aim of the present systematic literature review was to analyze the existing literature about the relationship between allergies and fatal and nonfatal suicidal behaviors.

METHODS

Data sources include articles retrieved from Scopus, PubMed, ProQuest, and Web of Knowledge. Search terms: "suicid* and (allerg* or hay fever or atop* or eczema or aeroallergen*)" in English-language peer-reviewed journals between 1990 and 2014.

ELIGIBILITY CRITERIA

Original research articles that provide empiric evidence about the potential link between allergies and suicidal behaviors.

RESULTS

The initial search identified a total of 769 articles with 17 original research articles that present empiric evidence. Nine articles analyzed the relationship between allergies and fatal suicidal behavior, and nine analyzed nonfatal suicidal behaviors (one article included both). There currently is little research into the relationship between allergies and suicidal behavior.

LIMITATIONS

The review was restricted to English-language articles published within the chosen time period; other limitations included the small number of articles that involve suicide mortality, and the fact that the majority of articles originated from the United States and Scandinavia.

CONCLUSIONS

Analysis of the results indicates a link between allergies and suicidality, particularly suicide mortality; however, results for nonfatal suicidal behaviors are mixed. It is important that further research by using more rigorous study designs be carried out to lend strength to these findings.