Department of Public Health, Section of Social Medicine, University of Copenhagen, Øster Farimagsgade 5, Copenhagen K 1014, Denmark; Department of Public Health, Unit of Epidemiology, Biostatistics, and Biodemography, University of Southern Denmark, J. B. Winsløws Vej 9B, Odense C 5000, Denmark; Center for Clinical Research and Disease Prevention, Bispebjerg and Frederiksberg Hospital, Capital Region, Copenhagen, Denmark; Danish Aging Research Center, Department of Public Health, University of Southern Denmark, Denmark.
Center for Healthy Aging, University of Copenhagen, Denmark; Department of Public Health, Section of Epidemiology, University of Copenhagen, Øster Farimagsgade 5, Copenhagen K 1014, Denmark.
J Affect Disord. 2018 Aug 1;235:162-167. doi: 10.1016/j.jad.2018.04.035. Epub 2018 Apr 5.
Early life cognitive ability (CA) might influence the risk of developing major depression (MD). The aim was to investigate the association between young adult CA and subsequent MD in relation to different MD disease characteristics.
Information on CA was assessed at conscription board examinations 1957-1984 (mean age 19 years) and information on MD was based on hospital diagnosis retrieved from Danish Patient registers 1969-2015. Associations between CA and MD were examined using Cox regression analyses.
A total of 666,804 men (born 1939-1959) were followed and 25,841 (3.9%) developed MD during a mean follow-up of 40.8 years. Lower CA was associated with an increased risk of incident MD. The association was stronger for early-onset (<60 years) (HR = 1.23; 95%CI:1.21,1.24) compared to late-onset (≥60 years) MD (HR = 1.14; 95%CI:1.11,1.16), but CA was not related to number of depressive episodes. The association was stronger for single depressive episodes (HR = 1.21; 95%CI:1.19,1.23) compared to recurrent depression (HR = 1.13; 95%CI:1.09,1.16), while the strength of the association did not differ according to MD disease severity (ICD10: mild, moderate, and severe depression).
The study sample only included men and only MD cases diagnosed at hospital were included which limits the generalizability.
Low CA could be a risk factor for especially early onset MD in men, whereas the influence of CA on re-occurrence seems less strong. Lower pre-morbid CA increases the risk of MD and should therefore be part of the depression risk assessment in clinical practice.
早期认知能力（CA）可能会影响发生重度抑郁症（MD）的风险。本研究旨在调查青年期 CA 与随后 MD 之间的关系，同时考虑到不同 MD 疾病特征。
CA 信息在入伍体检（1957-1984 年；平均年龄 19 岁）时进行评估，MD 信息则基于 1969-2015 年丹麦患者登记系统中的医院诊断。使用 Cox 回归分析来检验 CA 与 MD 之间的关联。
共纳入 666804 名男性（1939-1959 年出生），平均随访 40.8 年后，有 25841 人（3.9%）发生 MD。较低的 CA 与发生 MD 的风险增加相关。与晚发性 MD（≥60 岁）相比，早发性 MD（<60 岁）的相关性更强（HR=1.23；95%CI：1.21，1.24），但 CA 与抑郁发作次数无关。与复发性抑郁（HR=1.13；95%CI：1.09，1.16）相比，单发性抑郁发作（HR=1.21；95%CI：1.19，1.23）的相关性更强，而 CA 与 MD 严重程度（ICD10：轻度、中度和重度抑郁）之间的关联强度无差异。
研究样本仅包括男性，且仅纳入在医院诊断的 MD 病例，这限制了研究结果的推广性。
在男性中，低 CA 可能是早发性 MD 的一个危险因素，而 CA 对复发的影响似乎较弱。较低的发病前 CA 会增加 MD 的风险，因此应作为临床实践中抑郁风险评估的一部分。
