Parental history of psychiatric diagnoses and unipolar depression: a Danish National Register-based cohort study

Association between depression, antidepressant use, and the incidence of atherosclerotic cardiovascular diseases

OBJECTIVE

To examine the association between depression, the use of antidepressants, and atherosclerotic cardiovascular disease (ASCVD).

METHODS

The South Korean national claims data was used. Among a nationally representative population, 273,656 subjects who had been diagnosed with depression and prescribed antidepressants ("DEP with antidepressants") and 78,851 subjects who had been diagnosed with depression but not prescribed antidepressants ("DEP without antidepressants") were identified to be eligible. Healthy controls (HCs) were 1:1 matched with DEP with antidepressants group for age and sex. We followed up on the occurrence of ASCVD including ischemic heart diseases and ischemic stroke.

RESULTS

The risk of ASCVD was increased in the DEP with antidepressants group and decreased in the DEP without antidepressants group compared to HCs. Among those under antidepressants, tricyclic antidepressant users showed the highest risk of ASCVD compared to HCs. Among young adults, the risk of ASCVD was increased in both groups.

CONCLUSION

The risk of ASCVD increased in depression patients taking antidepressants, while it decreased in depression patients not taking antidepressants. However, the relationship showed differences according to drug class and age group.

Depression, antidepressant use, and the risk of type 2 diabetes: a nationally representative cohort study

Background

Previous studies have reported that depression can increase the risk of type 2 diabetes. However, they did not sufficiently consider antidepressants or comorbidity.

Methods

The National Health Insurance Sharing Service database was used. Among the sample population, 276,048 subjects who had been diagnosed with depression and prescribed antidepressants (DEP with antidepressants group) and 79,119 subjects who had been diagnosed with depression but not prescribed antidepressants (DEP without antidepressants group) were found to be eligible for this study. Healthy controls (HCs) were 1:1 matched with the DEP with antidepressants group for age and sex. We followed up with them for the occurrence of type 2 diabetes.

Results

In the group of DEP with antidepressants, although the risk of type 2 diabetes increased compared to HCs in a crude analysis, it decreased when comorbidity was adjusted for. In the group of DEP without antidepressants, the risk of type 2 diabetes decreased both in the crude model and the adjusted models. The risk varied by age group and classes or ingredients of antidepressants, with young adult patients showing an increased risk even in the fully adjusted model.

Conclusion

Overall, those with depression had a reduced risk of type 2 diabetes. However, the risk varied according to the age at onset, comorbidity, and type of antidepressants.

Paternal Depression and Risk of Depression Among Offspring: A Systematic Review and Meta-Analysis

Importance

Existing epidemiological evidence is equivocal as to whether paternal depression poses a consequent risk of depression in offspring; meta-analysis of findings can help inform preventative intervention efforts.

Objective

To conduct a systematic review and meta-analysis of observational studies examining the association between paternal and offspring depression.

Data Sources

Embase, PubMed, PsycINFO, Scopus, and Web of Science databases were searched between inception and December 2022.

Study Selection

The review included all observational studies that investigated the association between paternal and offspring depression and 10 606 studies were initially identified.

Data Extraction and Synthesis

This systematic review and meta-analysis was performed following the Preferred Reporting Items for Systematic Review and Meta-analysis guidelines. The review protocol was prospectively registered in PROSPERO. Summary odds ratios (ORs) and 95% CIs were pooled using inverse variance weighted random effect meta-analysis. Subgroup and sensitivity analyses were performed.

Main Outcomes and Measures

The main outcome of interest was offspring depression measured using recognized depression assessment tools.

Results

Sixteen observational studies published between 2002 and 2021 were included, with a combined sample of 7 153 723 father-child dyads. A meta-analysis of these studies showed that paternal depression was associated with an increased risk of depression in offspring (OR, 1.42; 95% CI, 1.17-1.71). The risk was higher among offspring exposed to paternal depressive disorders (OR, 1.65; 95% CI, 1.28-2.12) than those exposed to depression as defined by a nonclinical symptom scale (OR, 1.12; 95% CI, 1.06-1.19). Sensitivity analysis revealed consistent pooled estimates ranging from 1.35 (95% CI, 1.12-1.62) to 1.45 (95% CI, 1.18-1.78).

Conclusions and Relevance

Paternal depression was associated with subsequent offspring depression. This finding shows the intergenerational transmission of mental health problems and suggests that mental health interventions benefit not only the patient but also the family as a whole, including both parents.

Association of Familial Aggregation of Major Depression With Risk of Major Depression

Importance

Major depression (MD) aggregates within families, but how family history of MD confers risk of MD over the life course is unclear. Such knowledge is important to identify and prevent possible depressogenic effects of family environment.

Objective

To examine the association between family MD history and risk of MD including association with age, sex, type of kinship, and age of the affected family member.

Design, Setting, and Participants

This cohort study included all Danish citizens born from 1960 to 2003 with known parental identity followed up from their 15th birthday until time of MD, censoring, or December 31, 2018. Analysis took place between April 2022 and December 2022.

Exposures

Family members with first-time MD using International Classification of Diseases, Eighth Revision codes 296.09, 296.29, 298.09, and 300.49 or 10th Revision codes F32.0-F33.9, family members' age at MD onset, and individuals' age at exposure to family MD.

Main Outcomes and Measures

Multivariable Poisson regression was applied to estimate the incidence rate ratio (IRR) with 95% CI of first-time MD.

Results

Of 2 903 430 individuals (1 486 574 [51.2%] men), 37 970 men (2.6%) and 70 223 women (5.0%) developed MD during follow-up. For men, exposure to maternal, paternal, or full sibling MD were associated with a 2-times higher risk of MD (IRR, 2.10 [95% CI, 2.02-2.19]; IRR, 2.04 [95% CI, 1.94-2.14]; IRR, 2.08 [95% CI, 1.97-2.19]) and the associated risk increased with number of affected family members. This pattern was similar for women. For men, family members' age at MD onset was not associated with MD. For women, maternal MD onset at 69 years or younger was associated with higher IRRs of MD (age <40 years: IRR, 1.64 [95% CI, 1.28-2.10]; age 40-49 years: IRR, 1.62 [95% CI, 1.27-2.07]; age 50-59 years: IRR, 1.56 [95% CI, 1.22-2.00]; and age 60-69 years: IRR, 1.67 [95% CI, 1.28-2.16]) compared with women with maternal MD onset at 70 years or older. For men, exposure to maternal MD younger than 30 years (age <1 year: IRR, 1.95 [95% CI, 1.70-2.25]; age 1 to <12 years: IRR, 2.31 [95% CI, 2.16-2.47]; age 12 to <19 years: IRR, 2.18 [95% CI, 2.03-2.35]; age 19 to <30 years: IRR, 1.42 [95% CI, 1.32-1.53]) was associated with increased IRRs, while exposure to maternal MD at 30 years or older was associated with a lower IRR (0.77 [95% CI, 0.70-0.85]). The findings were similar across type of kinships and for women.

Conclusions and Relevance

In this study, risk of MD was associated with increased numbers of affected family members but did not vary by gender or type of kinship. Exposure to family MD during childhood and adolescence was associated with increased risk.

Attention-deficit/hyperactivity disorder and other neurodevelopmental disorders in offspring of parents with depression and bipolar disorder

BACKGROUND

Offspring of parents with major mood disorders (MDDs) are at increased risk for early psychopathology. We aim to compare the rates of neurodevelopmental disorders in offspring of parents with bipolar disorder, major depressive disorder, and controls.

METHOD

We established a lifetime diagnosis of neurodevelopmental disorders [attention-deficit/hyperactivity disorder (ADHD), autism spectrum disorder, communication disorders, intellectual disabilities, specific learning disorders, and motor disorders] using the Kiddie Schedule for Affective Disorders and Schizophrenia, Present and Lifetime Version in 400 participants (mean age 11.3 + s.d. 3.9 years), including 93 offspring of parents with bipolar disorder, 182 offspring of parents with major depressive disorder, and 125 control offspring of parents with no mood disorder.

RESULTS

Neurodevelopmental disorders were elevated in offspring of parents with bipolar disorder [odds ratio (OR) 2.34, 95% confidence interval (CI) 1.23-4.47, p = 0.010] and major depressive disorder (OR 1.87, 95% CI 1.03-3.39, p = 0.035) compared to controls. This difference was driven by the rates of ADHD, which were highest among offspring of parents with bipolar disorder (30.1%), intermediate in offspring of parents with major depressive disorder (24.2%), and lowest in controls (14.4%). There were no significant differences in frequencies of other neurodevelopmental disorders between the three groups. Chronic course of mood disorder in parents was associated with higher rates of any neurodevelopmental disorder and higher rates of ADHD in offspring.

CONCLUSIONS

Our findings suggest monitoring for ADHD and other neurodevelopmental disorders in offspring of parents with MDDs may be indicated to improve early diagnosis and treatment.

Physical activity and cardiovascular health in depression: Links between changes in physical activity and cardiovascular risk

OBJECTIVE

To examine the association between changes in physical activity before and after a diagnosis of depression and risks of cardiovascular diseases (CVDs) and all-cause mortality.

METHOD

A total of 1,282,160 patients with depression were included in the analyses. Subjects were divided into four groups (never, beginning, maintenance, and discontinuation) according to changes in physical activity before and after the diagnosis of depression. The occurrence of CVD including myocardial infarction (MI) and ischemic stroke and all-cause mortality were determined.

RESULTS

The beginning group showed decreased risks of MI (adjusted hazard ratio [aHR]: 0.85; 95% confidence interval [CI]: 0.81-0.89), ischemic stroke (aHR: 0.89; 95% CI: 0.85-0.93), and all-cause mortality (aHR: 0.80; 95% CI: 0.77-0.82) than the never group. Compared to the maintenance group, the discontinuation group showed increased risks of MI (aHR: 1.15; 95% CI: 1.08-1.23), ischemic stroke (aHR: 1.13; 95% CI: 1.06-1.21), and all-cause mortality (aHR: 1.29; 95% CI: 1.23-1.35).

CONCLUSIONS

Beginning regular physical activity after a diagnosis of depression was associated with a decreased cardiovascular risk. Discontinuing regular physical activity after a diagnosis of depression was associated with an increased cardiovascular risk.

Impaired Oxygenation of the Prefrontal Cortex During Verbal Fluency Task in Young Adults With Major Depressive Disorder and Suicidality: A Functional Near-Infrared Spectroscopy Study

BACKGROUND

Few previous studies have focused on prefrontal activation in young adults diagnosed with major depressive disorder (MDD) and suicidality via functional near-infrared spectroscopy (fNIRS).

MATERIALS AND METHODS

A total of 59 healthy controls (HCs), 35 patients with MDD but without suicidality, and 25 patients with MDD and suicidality, between the ages of 18-34 years, were enrolled. Changes in oxygenated hemoglobin (oxy-Hb) levels of the prefrontal cortex at baseline, 4 weeks, and 8 weeks, were evaluated using a protocol consisting of three consecutively repeated trials of rest, speech, and verbal fluency test (VFT) via fNIRS. MDD was diagnosed and suicidality was evaluated based on Mini International Neuropsychiatric Interview (MINI).

RESULTS

Oxy-Hb levels were impaired in patients with MDD compared with HCs (p = 0.018 for left prefrontal cortex; p = 0.021 for right ventromedial prefrontal cortex; p = 0.002 for left frontopolar cortex). Among the three groups including HCs, MDD without suicidality, and MDD with suicidality, prefrontal oxygenation was most decreased in MDD patients with suicidality. A significantly impaired prefrontal oxygenation in the right ventrolateral prefrontal cortex (VLPFC) was detected after adjusting for covariates in MDD patients with suicidality, compared to those without suicidality.

CONCLUSION

Impaired prefrontal oxygenation during cognitive execution may serve as a diagnostic biomarker for suicidality in young adult patients with MDD.

Risk of Early-Onset Depression Associated With Polygenic Liability, Parental Psychiatric History, and Socioeconomic Status

IMPORTANCE

Combining information on polygenic risk scores (PRSs) with other known risk factors could potentially improve the identification of risk of depression in the general population. However, to our knowledge, no study has estimated the association of PRS with the absolute risk of depression, and few have examined combinations of the PRS and other important risk factors, including parental history of psychiatric disorders and socioeconomic status (SES), in the identification of depression risk.

OBJECTIVE

To assess the individual and joint associations of PRS, parental history, and SES with relative and absolute risk of early-onset depression.

DESIGN, SETTING, AND PARTICIPANTS

This case-cohort study included participants from the iPSYCH2012 sample, a case-cohort sample of all singletons born in Denmark between May 1, 1981, and December 31, 2005. Hazard ratios (HRs) and absolute risks were estimated using Cox proportional hazards regression for case-cohort designs.

EXPOSURES

The PRS for depression; SES measured using maternal educational level, maternal marital status, and paternal employment; and parental history of psychiatric disorders (major depression, bipolar disorder, other mood or psychotic disorders, and other psychiatric diagnoses).

MAIN OUTCOMES AND MEASURES

Hospital-based diagnosis of depression from inpatient, outpatient, or emergency settings.

RESULTS

Participants included 17 098 patients with depression (11 748 [68.7%] female) and 18 582 (9429 [50.7%] male) individuals randomly selected from the base population. The PRS, parental history, and lower SES were all significantly associated with increased risk of depression, with HRs ranging from 1.32 (95% CI, 1.29-1.35) per 1-SD increase in PRS to 2.23 (95% CI, 1.81-2.64) for maternal history of mood or psychotic disorders. Fully adjusted models had similar effect sizes, suggesting that these risk factors do not confound one another. Absolute risk of depression by the age of 30 years differed substantially, depending on an individual's combination of risk factors, ranging from 1.0% (95% CI, 0.1%-2.0%) among men with high SES in the bottom 2% of the PRS distribution to 23.7% (95% CI, 16.6%-30.2%) among women in the top 2% of PRS distribution with a parental history of psychiatric disorders.

CONCLUSIONS AND RELEVANCE

This study suggests that current PRSs for depression are not more likely to be associated with major depressive disorder than are other known risk factors; however, they may be useful for the identification of risk in conjunction with other risk factors.

Parental age and risk of depression: A nationwide, population-based case-control study

BACKGROUND

The global prevalence of depression has increased in recent decades and so has the average age of parenthood. Younger and older parental age have been associated with several mental disorders in their offspring, but the associations for depression have been inconsistent.

METHODS

This study comprised 37,682 singleton births in Finland from 1987- 2007. The subjects were living in Finland at the end of 2012 and had a depressive disorder recorded in the Care Register for Health Care. We also randomly identified 148,795 controls from the Population Register. When missing obsevations excluded the sample was N_cases=18,708 and N_controls=77,243. The results were adjusted for the parents' psychiatric history, depression history, marital status and place of birth, the mothers' maternal socioeconomic status, smoking during pregnancy and previous births and the children's birth weight.

RESULTS

We found a U-shaped association between offspring depression and the age of both parents. The highest odds of depression occurred when the fathers were aged 50 plus years (adjusted Odds Ratio (ORa) 1.51, 95% CI 1.23-1.86) and the mothers were under 20 (ORa 1.44, 95% CI 1.29-1.60) compared to the reference category of parents aged 25-29 years.

LIMITATIONS

The study was limited to depression diagnosed by specialised health care services and had a relatively short follow-up period. Some data were missing and that could lead to risk estimation biases.

CONCLUSION

Diagnosed depression was higher among the offspring of younger and older parents. The results suggest that the age of the parent is etiologically associated with offspring depression.

Association of Polygenic Liabilities for Major Depression, Bipolar Disorder, and Schizophrenia With Risk for Depression in the Danish Population

IMPORTANCE

Although the usefulness of polygenic risk scores as a measure of genetic liability for major depression (MD) has been established, their association with depression in the general population remains relatively unexplored.

OBJECTIVE

To evaluate whether polygenic risk scores for MD, bipolar disorder (BD), and schizophrenia (SZ) are associated with depression in the general population and explore whether these polygenic liabilities are associated with heterogeneity in terms of age at onset and severity at the initial depression diagnosis.

DESIGN, SETTING, AND PARTICIPANTS

Participants were drawn from the Danish iPSYCH2012 case-cohort study, a representative sample drawn from the population of Denmark born between May 1, 1981, and December 31, 2005. The hazard of depression was estimated using Cox regressions modified to accommodate the case-cohort design. Case-only analyses were conducted using linear and multinomial regressions. The data analysis was conducted from February 2017 to June 2018.

EXPOSURES

Polygenic risk scores for MD, BD, and SZ trained using the most recent genome-wide association study results from the Psychiatric Genomics Consortium.

MAIN OUTCOMES AND MEASURES

The main outcome was first depressive episode (International Statistical Classification of Diseases and Related Health Problems, Tenth Revision [ICD-10] code F32) treated in hospital-based psychiatric care. Severity at the initial diagnosis was measured using the ICD-10 code severity specifications (mild, moderate, severe without psychosis, and severe with psychosis) and treatment setting (inpatient, outpatient, and emergency).

RESULTS

Of 34 573 participants aged 10 to 31 years at censoring, 68% of those with depression were female compared with 48.9% of participants without depression. Each SD increase in polygenic liability for MD, BD, and SZ was associated with 30% (hazard ratio [HR], 1.30; 95% CI, 1.27-1.33), 5% (HR, 1.05; 95% CI, 1.02-1.07), and 12% (HR, 1.12; 95% CI, 1.09-1.15) increases in the hazard of depression, respectively. Among cases, a higher polygenic liability for BD was associated with earlier depression onset (β = -.07; SE = .02; P = .002).

CONCLUSIONS AND RELEVANCE

Polygenic liability for MD is associated with first depression in the general population, which supports the idea that these scores tap into an underlying liability for developing the disorder. The fact that polygenic risk for BD and polygenic risk for SZ also were associated with depression is consistent with prior evidence that these disorders share some common genetic overlap. Variations in polygenic liability may contribute slightly to heterogeneity in clinical presentation, but these associations appear minimal.

Characterizing Developmental Trajectories and the Role of Neuropsychiatric Genetic Risk Variants in Early-Onset Depression

Importance

Depression often first manifests in adolescence. Thereafter, individual trajectories vary substantially, but it is not known what shapes depression trajectories in youth. Adult studies suggest that genetic risk for schizophrenia, a psychiatric disorder with a neurodevelopmental component, may contribute to an earlier onset of depression.

Objective

To test the hypothesis that there are distinct trajectories of depressive symptoms and that genetic liability for neurodevelopmental psychiatric disorders (eg, schizophrenia, attention deficit/hyperactivity disorder [ADHD]), as well as for major depressive disorder (MDD), contribute to early-onset depression.

Design, Setting, and Participants

The Avon Longitudinal Study of Parents and Children is an ongoing, prospective, longitudinal, population-based cohort that has been collecting data since September 6, 1990, including data on 7543 adolescents with depressive symptoms at multiple time points. The present study was conducted between November 10, 2017, and August 14, 2018.

Main Outcomes and Measures

Trajectories based on self-reported depressive symptoms dichotomized by the clinical cutpoint; MDD, schizophrenia, and ADHD polygenic risk score (PRS) were predictors.

Results

In 7543 adolescents with depression data on more than 1 assessment point between a mean (SD) age of 10.64 (0.25) years and 18.65 (0.49) years (3568 [47.3%] male; 3975 [52.7%] female), 3 trajectory classes were identified: persistently low (73.7%), later-adolescence onset (17.3%), and early-adolescence onset (9.0%). The later-adolescence-onset class was associated with MDD genetic risk only (MDD PRS: odds ratio [OR], 1.27; 95% CI, 1.09-1.48; P = .003). The early-adolescence-onset class was also associated with MDD genetic risk (MDD PRS: OR, 1.24; 95% CI, 1.06-1.46; P = .007) but additionally with genetic risk for neurodevelopmental disorders (schizophrenia PRS: OR, 1.22; 95% CI, 1.04-1.43; P = .01; ADHD PRS: OR, 1.32; 95% CI, 1.13-1.54; P < .001) and childhood ADHD (χ21 = 6.837; P = .009) and neurodevelopmental traits (pragmatic language difficulties: OR, 1.31; P = .004; social communication difficulties: OR, 0.68; P < .001).

Conclusions and Relevance

The findings of this study appear to demonstrate evidence of distinct depressive trajectories, primarily distinguished by age at onset. The more typical depression trajectory with onset of clinically significant symptoms at age 16 years was associated with MDD genetic risk. The less-common depression trajectory, with a very early onset, was particularly associated with ADHD and schizophrenia genetic risk and, phenotypically, with childhood ADHD and neurodevelopmental traits. Findings are consistent with emerging evidence for a neurodevelopmental component in some cases of depression and suggest that the presence of this component may be more likely when the onset of depression is very early.

Vascular Pathology and Trajectories of Late-Life Major Depressive Disorder in Secondary Psychiatric Care

OBJECTIVE

To examine 5-year trajectories of psychiatrist-treated late-life major depressive disorder (MDD), and evaluate whether previous vascular pathology is associated with more severe trajectories of late-life MDD.

METHODS

Data were obtained from nationally representative civil, psychiatric, hospital, and prescription registers in Denmark. The sample included 11,092 older adults (≥60 years) who received their first diagnosis of MDD in a psychiatric facility in Denmark between 2000 and 2007. Trajectories of inpatient or outpatient contact at psychiatric hospitals for MDD over the 5-year period following index MDD diagnosis were modeled using latent class growth analysis. Measures of vascular disease (stroke, heart disease, vascular dementia) and vascular risk factors (hypertension, diabetes) were defined based on medication prescriptions and hospital-based diagnoses. Other predictors included demographic characteristics and characteristics of the index MDD diagnosis.

RESULTS

The final model included 4 trajectories with consistently low (66% of the sample), high decreasing (19%), consistently high (9%), and moderate fluctuating (6%) probabilities of contact at a psychiatric hospital for MDD during the 5-year period following the index MDD diagnosis. We found no significant associations between any form of vascular pathology and trajectory class membership. Relative to the consistently low class, older age, greater severity and >12 months of prior antidepressant medication use predicted membership in the other three classes.

CONCLUSIONS

A notable proportion (34%) of individuals diagnosed with MDD in late-life require secondary psychiatric treatment for extended time periods. We did not find evidence that vascular pathology predicts hospital contact trajectories in secondary-treated late-life MDD.

The association between paternal and adolescent depressive symptoms: evidence from two population-based cohorts

BACKGROUND

Incidence of depression increases markedly around age 13 years, and nearly three-quarters of adults report that their mental health problems started in adolescence. Although maternal depression is a risk factor for adolescent depression, evidence about the association between paternal and adolescent depression is inconclusive, and many studies have methodological limitations. We aimed to assess the association between paternal and adolescent depressive symptoms in two large population-based cohort studies.

METHODS

We used data for two-parent families from two representative prospective cohorts in Ireland (Growing up in Ireland [GUI]) and the UK (Millennium Cohort Study [MCS]). Parental depressive symptoms were measured with the Centre for Epidemiological Studies Depression Scale in the GUI cohort when children were 9 years old, and the Kessler six-item psychological distress scale in the MCS cohort when children were 7 years old. Adolescent depressive symptoms were measured with the Short Mood and Feelings Questionnaire (SMFQ) at age 13 years in the GUI cohort and age 14 years in the MCS cohort. We analysed data using linear regression models, before and after adjustment for confounders, in both multiply imputed and complete case samples.

FINDINGS

There were 6070 families in GUI and 7768 in MCS. After all adjustments, a 1 SD (three-point) increase in paternal depressive symptoms was associated with an increase of 0·24 SMFQ points (95% CI 0·03-0·45; p=0·023) in the GUI cohort and 0·18 SMFQ points (0·01-0·36; p=0·041) in the MCS cohort. This association was independent of, and not different in magnitude to, the association between maternal and adolescent depressive symptoms (Wald test p=0·435 in the GUI cohort and 0·470 in the MCS cohort).

INTERPRETATION

Our results show an association between depressive symptoms in fathers and depressive symptoms in their adolescent offspring. These findings support the involvement of fathers as well as mothers in early interventions to reduce the prevalence of adolescent depression, and highlight the importance of treating depression in both parents.

FUNDING

Department of Children and Youth Affairs and Economic and Social Research Council.

Early adversity and risk for moderate to severe unipolar depressive disorder in adolescence and adulthood: A register-based study of 978,647 individuals

BACKGROUND

Early adversity is a known risk factor for unipolar depression. We examined the impact of 9 types of early adversity on risk for moderate to severe unipolar depression in adolescence or adulthood, and evaluated whether these effects were moderated by gender and adversity timing.

METHODS

We conducted a prospective, population-based cohort study using Danish national registers. The sample included all individuals born in Denmark between 1980 and 1998 (N=978,647). Exposure to early adversity was assessed from ages 0-15. Types of adversity included parental illness, incarceration, death, disability, and psychiatric diagnosis; family disruption; out-of-home care; and childhood abuse. Individuals were followed from age 15 until first in- or outpatient depression diagnosis (ICD-10 codes F32, F33) in a psychiatric hospital, death, emigration, or December 31st, 2013, whichever came first. Hazard ratios (HRs) were calculated using Cox regressions.

RESULTS

All adversities were significantly associated with increased risk for moderate to severe adolescent/adult depression (HR range: 1.30-2.72), although the effects were attenuated after mutual adjustment (adjusted HR range: 1.06-1.70). None of the effects were moderated by gender. The effect of family disruption was strongest between ages 0-4 (HR=1.66, 95% CI=1.61-1.71), while the effect of out-of-home care was strongest between ages 10-14 (HR=2.45, 95% CI=2.28-2.64).

LIMITATIONS

Untreated and primary-care treated depression were not measured.

CONCLUSIONS

Our results support past findings that multiple types of early adversity increase risk for moderate to severe unipolar depression in adolescence and adulthood. Certain adversities may be more harmful if they occur during specific developmental time periods.