Independent associations between personality traits and clinical characteristics of depression.

Few studies have examined age of onset and chronicity of depression in the same subject sample. The present study sought to determine whether personality traits related to early onset depression were different from those related to chronic depression. We tested the associations between personality self-reports and clinical characteristics of depression by conducting multiple and logistic regression analyses to determine whether personality uniquely predicted clinical characteristics and whether clinical characteristics uniquely predicted personality, after adjusting for depression severity. We also analyzed data at 6-month follow-up to determine whether age of onset and chronicity maintained their associations with personality. The study found that low levels of positive personality traits had unique associations with chronicity of depression, whereas elevated levels of negative personality traits had unique associations with an earlier onset of depression. Furthermore, associations were generally maintained over time, suggesting that associations between personality and these depression subtypes are stable.