The association between absent lunula and depression in depressive outpatients: a case-control study.

Absent lunula can progressively develop in a person who previously had a normal-sized lunula and can be associated with various systemic disorders. In this case-control study we hypothesised that absent lunula is associated with depression. The study comprised 332 depressive outpatients as well as 367 age- and sex-matched controls, all of whom were assessed and screened by the Zung Self-rating Depression Scale (ZSDS). The presence of absent lunula in all fingers except the little finger on the right hand of subjects was examined and the number of absent lunula was calculated as 0, 1, 2, 3 and 4. It was revealed that there was no significant difference in age and gender between controls and depressive outpatients. In the order of 0, 1, 2, 3 and 4 absent lunula, the percentages were 68.1, 7.4, 9.5, 5.2 and 9.8 in controls, while it was 17.2, 15.4, 22.3, 21.4 and 23.7 in depressive outpatients with significant difference while they were 17.2, 15.4, 22.3, 21.4 and 23.7 in depressive outpatients, significantly different compared with controls. Logistic regression analysis on depressive outpatients indicated that severe depression was not associated with age and sex but markedly associated with number of absent lunula. Our study found that depression was associated with absent lunula, and severe depression was associated with a greater number of absent lunula.