Longitudinal association between cardiovascular risk factors and depression in young people: a systematic review and meta-analysis of cohort studies.

BACKGROUND: Depression is a common and serious mental illness that begins early in life. An association between cardiovascular disease (CVD) and subsequent depression is clear in adults. We examined associations between individual CVD risk factors and depression in young people. METHODS: We searched MEDLINE, EMBASE, and PsycINFO databases from inception to 1 January 2020. We extracted data from cohort studies assessing the longitudinal association between CVD risk factors [body mass index (BMI), smoking, systolic blood pressure (SBP), total cholesterol, high-density lipoprotein] and depression, measured using a validated tool in individuals with mean age of 24 years or younger. Random effect meta-analysis was used to combine effect estimates from individual studies, including odds ratio (OR) for depression and standardised mean difference for depressive symptoms. RESULTS: Based on meta-analysis of seven studies, comprising 15 753 participants, high BMI was associated with subsequent depression [pooled OR 1.61; 95% confidence interval (CI) 1.21-2.14; I2 = 31%]. Based on meta-analysis of eight studies, comprising 30 539 participants, smoking was associated with subsequent depression (pooled OR 1.73; 95% CI 1.36-2.20; I2 = 74%). Low, but not high, SBP was associated with an increased risk of depression (pooled OR 3.32; 95% CI 1.68-6.55; I2 = 0%), although this was based on a small pooled high-risk sample of 893 participants. Generalisability may be limited as most studies were based in North America or Europe. CONCLUSIONS: Targeting childhood/adolescent smoking and obesity may be important for the prevention of both CVD and depression across the lifespan. Further research on other CVD risk factors including blood pressure and cholesterol in young people is required.

Direction of association between Cardiovascular risk and depressive symptoms during the first 18 years of life: A prospective birth cohort study.

BACKGROUND: Cardiovascular disease (CVD) and depression are bidirectionally associated in adults. However, the direction of association between CVD risk and depressive symptoms in young people and potential mechanisms are poorly understood. METHODS: Using longitudinal birth cohort data, we created a CVD risk score age at 15 using age, ethnicity, physical activity, maternal social status, maternal smoking, own smoking, BMI, systolic blood pressure, LDL, HDL and triglycerides. We used regression analysis to test: (1) association between CVD risk score at age 15 and depressive symptoms at ages 12 and 18; (2) association of IL-6 and CRP at age 9 with depressive symptoms at age 12 and CVD risk score at age 15; and (3) mediating effects of CVD risk score on associations of IL-6/CRP at age 9 with depressive symptoms at age 18. RESULTS: The risk set comprised 5007 participants. CVD risk score in mid-adolescence was associated with depressive symptoms in early-adulthood (adjusted beta=0.06; standard error (SE)=0.02; p<0.001). Depressive symptoms in childhood were not associated with CVD risk score in mid-adolescence (adjusted beta=0.03; SE=0.02; p=0.11). Childhood inflammatory markers were associated with CVD risk score in mid-adolescence. Adolescent CVD risk score mediated the associations between childhood inflammatory markers and depressive symptoms in early-adulthood. LIMITATIONS: The cohort primarily comprises White individuals, limiting generalisability. Sample attrition required imputation for missing data. CONCLUSIONS: Association between CVD risk and depression in childhood/adolescence is unidirectional, with higher CVD risk increasing the risk of depressive symptoms. Childhood inflammation may increase risk of depression by influencing adolescent CVD risk.

Sexual and physical abuse and depressive symptoms in the UK Biobank.

BACKGROUND: The association between sexual and physical abuse and subsequent depression is well-established, but the associations with specific depressive symptoms and sex differences remain relatively understudied. We investigated the associations of sexual and physical abuse with depressive symptoms in men and women in a large population cohort. METHODS: Observational study based on 151,396 UK Biobank participants. Exposures included self-reported experiences of childhood physical abuse and sexual abuse. Mid-life outcomes included current depressive symptoms score, individual depressive symptoms, and lifetime depression. We used logistic regression to test associations of childhood sexual/physical abuse with depressive outcomes. RESULTS: Recalled childhood sexual and physical abuse were both associated with current depressive symptoms score in adults. Results for individual symptoms-based analyses suggest that sexual and physical abuse are associated with all depressive symptoms, particularly suicidal behaviours. The associations between lifetime depression and sexual/physical abuse were not fully explained by current depressive symptoms score, indicating that these findings may not be fully attributable to recall bias. There was no indication of differential risk for specific depressive symptoms among men and women. CONCLUSIONS: Sexual and physical abuse are robust risk factors for depression/depressive symptoms regardless of sex. Higher risk of suicidal behaviours associated with childhood sexual/physical abuse are of particular concern. Longitudinal research into sex-specific associations for individual depressive symptoms is required.

Association between common early-childhood infection and subsequent depressive symptoms and psychotic experiences in adolescence: a population-based longitudinal birth cohort study.

BACKGROUND: Childhood infections are associated with adult psychosis and depression, but studies of psychotic experiences (PEs) and depressive symptoms in childhood, adolescence, and early-adulthood are scarce. Previous studies have typically examined severe infections, but studies of common infections are also scarce. METHODS: Using data from the Avon Longitudinal Study of Parents and Children (ALSPAC) birth cohort, we examined associations of the number of infections in childhood from age 1.5 to 7.5 years with depressive symptom scores at age 10, 13, 14, 17, 18, and 19 years, and with PEs at 12 and 18 years. We performed additional analysis using infection burden ('low' = 0-4 infections, 'medium' = 5-6, 'high' = 7-9, or 'very high' = 10-22 infections) as the exposure. RESULTS: The risk set comprised 11 786 individuals with childhood infection data. Number of childhood infections was associated with depressive symptoms from age 10 (adjusted beta = 0.14; standard error (s.e.) = 0.04; p = <0.01) to 17 years (adjusted beta = 0.17; s.e. = 0.08; p = 0.04), and with PEs at age 12 (suspected/definite PEs: adjusted odds ratio (OR) = 1.18; 95% confidence interval (CI) = 1.09-1.27). These effect sizes were larger when the exposure was defined as very high infection burden (depressive symptoms age 17: adjusted beta = 0.79; s.e. = 0.29; p = 0.01; suspected/definite PEs at age 12: adjusted OR = 1.60; 95% CI = 1.25-2.05). Childhood infections were not associated with depressive/psychotic outcomes at age 18 or 19. CONCLUSIONS: Common early-childhood infections are associated with depressive symptoms up to mid-adolescence and with PEs subsequently in childhood, but not with these outcomes in early-adulthood. These findings require replication including larger samples with outcomes in adulthood.