title: Incidence of Major Depressive Disorder: Variation by Age and Sex in Low-Income Individuals: A Population-Based 10-Year Follow-Up Study.
abstract: Major depressive disorder (MDD), the most prevalent mental disorder is a global public health issue. The aim of this study was to assess the association between low income and major depressive disorder (MDD) by age and sex. The National Health Insurance Research Database (NHIRD) of Taiwan was used to retrieve data. A total of 1,743,948 participants were eligible for the study. Low-income individuals were identified from 2001 and 2003 (specifically, Group Insurance Applicants, ie, category"51" or "52") and followed from 2004 to 2010. MDD was identified using the ICD-9-CM 296.2 and 296.3 codes. Among non-low-income individuals, the MDD incidence rates increased with age in both males and females, that is, 0.35, 0.93, 0.97, 1.40 per 10,000 person-months for males and 0.41, 1.60, 1.89, 1.95 per 10,000 person-months for females aged 0 to 17, 18 to 44, 45 to 64, and ≥65 years, respectively. Low-income females (18-44 years) and males (45-64 years) had the highest incidence of MDD, which was 3.90 and 3.04, respectively, per 10,000 person-months. Among low and non-low-income individuals, the MDD incidence rates were higher in the females than males in all age groups. Males aged 45 to 64 and 0 to 17 years had highest hazard ratios (HR) of 2.789 (95% confidence interval [CI], 1.937-4.014) and 2.446 (95% CI, 1.603-3.732), respectively. The highest HRs for females were 2.663 (95% CI, 1.878-3.775) and 2.219 (CI, 1.821-2.705) in the 0 to 17 and 18- to 44-year age groups. Low income was not found to serve as a risk factor for the development of MDD in males and females aged ≥65 years. Among the non-low-income males and females, the incidence rates of MDD were found to increase with age. Low income was found to serve as a significant risk factor for MDD only in individuals under age 65.
authors.affiliation: From the Department of Psychiatry (C-TL); School of Medicine (C-TL); Department of Public Health and Institute of Public Health (Y-CC, J-YH, DMT, ONN, Y-PL); Department of Family and Community Medicine (Y-PL), Chung Shan Medical University Hospital, Taichung; Department of Psychiatry (J-FL), Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taipei; School of Medicine (J-FL), Tzu Chi University, Hualien; Institute of Medicine (C-CC), Chung Shan Medical University, Taichung; and Department of Psychiatry (C-CC), Changhua Christian Hospital, Changhua, Taiwan.
authors.forename: Chun-Te
authors.initials: CT
authors.lastname: Lee
authors.forename: Yi-Cheng
authors.initials: YC
authors.lastname: Chiang
authors.forename: Jing-Yang
authors.initials: JY
authors.lastname: Huang
authors.forename: Disline M
authors.initials: DM
authors.lastname: Tantoh
authors.forename: Oswald N
authors.initials: ON
authors.lastname: Nfor
authors.forename: Jia-Fu
authors.initials: JF
authors.lastname: Lee
authors.forename: Cheng-Chen
authors.initials: CC
authors.lastname: Chang
authors.forename: Yung-Po
authors.initials: YP
authors.lastname: Liaw
mesh_terms: D000293:Adolescent; D000328:Adult; D017677:Age Distribution; D000368:Aged; D003865:Major Depressive Disorder / Q000453:epidemiology*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011203:Poverty / Q000706:statistics & numerical data*; D015995:Prevalence; D012111:Residence Characteristics; D012307:Risk Factors; D017678:Sex Distribution; D013624:Taiwan / Q000453:epidemiology; D055815:Young Adult