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Socioeconomic factors and health
Associations of financial strain and income with depressive and anxiety disorders
  1. Sandra M A Dijkstra-Kersten1,
  2. Karolien E M Biesheuvel-Leliefeld1,
  3. Johannes C van der Wouden1,
  4. Brenda W J H Penninx2,
  5. Harm W J van Marwijk1
  1. 1Department of General Practice & Elderly Care Medicine and the EMGO+Institute for Health and Care Research (EMGO+), VU University Medical Center, Amsterdam, The Netherlands
  2. 2Department of Psychiatry and the EMGO+Institute for Health and Care Research (EMGO+), VU University Medical Center, Amsterdam, The Netherlands
  1. Correspondence to Sandra M A Dijkstra-Kersten, Department of General Practice & Elderly Care Medicine, Medicine and the EMGO+Institute for Health and Care Research (EMGO+), VU University Medical Center, Van der Boechorststraat 7, 1007 MB, Amsterdam, The Netherlands; s.kersten{at}vumc.nl

Abstract

Background Previous research has shown socioeconomic inequality in prevalence and onset of depressive disorders. It is not yet clear whether perceived financial strain is associated with depressive and/or anxiety disorders in addition to an objective indicator, such as income. This study examines whether financial strain is associated with the prevalence and onset/recurrence of depressive and/or anxiety disorders, above income.

Methods Data are from the Netherlands Study of Depression and Anxiety. Associations between financial strain, income and presence of depressive and/or anxiety disorder at baseline were assessed among 2937 participants (18–65 years). Impact of financial strain and income on 4-year onset/recurrence of depressive and/or anxiety disorders were examined among 1250 participants without a depressive or anxiety disorder at baseline. Depressive and anxiety disorders were determined with the Composite-International-Diagnostic-Interview. Financial strain and income were assessed in an interview.

Results Participants with mild or severe financial strain had higher odds of being depressed (OR=1.68, 95% CI 1.35 to 2.09; OR=3.88, 95% CI 2.58 to 5.81) or remitted (OR=1.56, 95% CI 1.24 to 1.96; OR=1.99, 95% CI 1.27 to 3.11) at baseline compared with healthy controls, after adjusting for income. Mild or severe financial strain was not associated with onset/recurrence of depressive and/or anxiety disorders during follow-up (OR=1.08, 95% CI 0.83 to 1.42; OR=1.05, 95% CI 0.64 to 1.73).

Conclusions Financial strain was associated with having a depressive and/or anxiety disorder, above the effect of income. Healthcare and social services should be alert to this association, even for higher income households. However, financial strain and income were not related with 4-year onset/recurrence of depressive and/or anxiety disorders.

  • DEPRESSION
  • SOCIAL INEQUALITIES
  • MENTAL HEALTH

https://doi.org/10.1136/jech-2014-205088

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    Introduction

    Owing to the current economic recession, more households have difficulties making ends meet.1 Socioeconomic characteristics, such as low income, low education level, debt and unemployment, are generally associated with higher rates of having mental health problems.2–4 These are objective indicators of a person's socioeconomic status. In previous research, these indicators have been linked with poor mental health and the strength of these associations vary with the type of indicator used.2 ,3 ,5–7 A systematic review by Fryers et al2, for instance, concluded that less education, lower income and unemployment provided more substantial evidence for social inequalities in prevalence of mental disorders than social status. A meta-analysis by Lorant et al3 indicated a stronger relation of depression with income than with education. Subjective indicators, however, such as perceived financial strain and subjective social class, have seldom been used. Perceived financial strain (henceforth called: financial strain) for instance, might be a better predictor of mental health problems.8 ,9 Financial strain may represent a tendency to worry10 and is not restricted to individuals with a low socioeconomic status; individuals in a high-income group or with a high socioeconomic status may also perceive financial strain, for example, as a result of an inappropriate standard of living.6 Financial strain could, therefore, be considered as a negative stressor which may increase the risk of mental health problems.6

    The current large scale study is one of the first to examine the effect of financial strain, as a subjective indicator of socioeconomic status, and income, as an objective indicator of socioeconomic status, on depressive and/or anxiety disorders in a multisite naturalistic cohort.11 So far only few studies focused on the effect of financial strain on depressive and/or anxiety disorders. They indicate that financial strain may be associated with an increased risk of depressive symptoms,5 ,12 ,13 depressive disorders5 ,6 or common mental disorders.10 Only one study6 used standardised clinical assessments, while others used symptom-checklists or general practitioners’ records. Furthermore, none of these studies examined anxiety disorders, although anxiety disorders frequently co-occur with depressive disorders. Because of these limitations and different methodologies, the exact relationships between financial strain, income and depressive and/or anxiety disorders are still not clear.

    In order to examine the impact of financial strain on the prevalence and onset/recurrence of depressive and/or anxiety disorders and to assess whether this effect is over and above the effect of income, this study used cross-sectional and longitudinal data. We hypothesised that perceiving more financial strain is associated with (1) higher prevalence and (2) higher 4-year onset/recurrence of depressive and/or anxiety disorders. It is furthermore hypothesised that the associations between financial strain and (3) the prevalence and (4) onset/recurrence of depressive and anxiety disorders are independent from baseline income.

    Methods

    Study sample

    The present study is part of the Netherlands Study of Depression and Anxiety (NESDA), an ongoing naturalistic multisite cohort study which investigates predictors, long-term course and consequences of depressive and anxiety disorders.11 A total of 2981 participants (18–65 years) were recruited from community, general practice and secondary mental healthcare. The sample consisted of healthy controls, persons with a prior history of depression and/or anxiety, and persons with a current depressive and/or anxiety disorder. Exclusion criteria were not being fluent in Dutch and a primary diagnosis of psychotic, obsessive compulsive, bipolar or severe substance-use disorder. Baseline data collection took place between 2004 and 2007. Assessments were repeated every 2 years. The NESDA design is described elsewhere in more detail.11 The research protocol was approved by the Ethical Committee of participating universities and has been performed in accordance with the ethical standards of the Declaration of Helsinki.

    We used two samples from the NESDA-cohort. The first sample consisted of all participants (N=2981), regardless of their psychiatric status at baseline. In this sample, the association between financial strain and depressive and/or anxiety disorders was assessed (hypothesis 1) and whether this association was independent from income (hypothesis 3). Only data from the baseline assessment were used. Forty-four participants who did not provide all required data were excluded from analyses (N=2937). The second sample was restricted to 1525 participants without a current depressive or anxiety disorder at baseline (see Depressive and/or anxiety disorders section for definition) in order to examine the effect of financial strain on the 4-year new onset/recurrence of depressive and/or anxiety disorders (hypothesis 2) and whether this effect was over and above the effect of income (hypothesis 4). Of these eligible participants, 1299 participated in the 2-year and 4-year follow-up assessments, while 1250 provided all required data, which were used for our longitudinal analyses.

    Measurements

    Financial characteristics

    At baseline, data on income and financial strain were collected in a face-to-face interview. The net household income per month was measured with 24 categories ranging from ‘less than €600 per month’ to ‘more than €5000 per month’ with step gradations of €300. This variable was transformed to (approximate) interval level ranging from €500 to €6200 per month by replacing each category by its midpoint value. Financial strain was measured with the question: “In general: how is your financial status at the end of the month?” Possible answers were: ‘usually money left’ (considered as no financial strain; reference category), ‘just enough money to manage’ (mild financial strain) and ‘not enough money to manage’ (severe financial strain).

    Depressive and/or anxiety disorders

    Depressive (ie, major depressive disorder and dysthymia) or anxiety (ie, agoraphobia, social phobia, panic and generalised anxiety disorder) disorders were diagnosed at baseline, 2-year and 4-year follow-up with the Composite International Diagnostic Interview (CIDI, V.2.1).14 If participants reported any diagnosis, a Life Chart Interview (LCI) was conducted.15 Life events were recalled to refresh memory using a calendar method, after which depressive and/or anxiety symptoms in each month were determined retrospectively. In addition, symptom severity was assessed for each month. Symptoms reported during LCI were only considered present when at least of mild severity.

    The presence of a depressive and/or anxiety disorder at baseline was considered as the outcome for the first and third hypothesis (cross-sectional analysis). Presence of a depressive and/or anxiety disorder at baseline was defined, according to the CIDI and LCI, as all participants with (1) a diagnosis of a depressive and/or anxiety disorder in the previous month, or (2) a diagnosis of a depressive and/or anxiety disorder in the previous 6 months and having had substantial depressive or anxiety symptoms in the year previous to baseline. Three categories were created for this outcome measure (1) healthy control: neither a lifetime nor current depressive and/or anxiety disorder; (2) remitted, lifetime depressive and/or anxiety disorder but no current disorder; (3) current depressive and/or anxiety disorder.

    Based on the CIDI, the onset of a depressive and/or anxiety disorder (regardless of the presence of an earlier diagnosis before baseline; the term ‘onset’ is used for both new onset and recurrence of depressive and/or anxiety disorders) anytime between baseline and the 4-year follow-up was used for our second and forth hypotheses (longitudinal analysis).

    Sociodemographic characteristics

    Sociodemographic characteristics included were: age, gender, number of years of education, partner status (yes/no) and employment status.

    Statistical analyses

    Baseline characteristics were compared across baseline psychiatric status using χ2 statistics and analyses of variance.

    We used multinomial logistic regression analysis to assess the associations between financial strain, income and the presence of a depressive and/or anxiety disorder at baseline (analysis 1: cross-sectional). Participants who had never had a depressive and/or anxiety disorder were used as reference group and were compared with participants who were remitted and with participants who had a current depressive and/or anxiety disorder at baseline. Logistic regression analysis was used to examine the effect of financial strain and income on the onset/recurrence of depressive and/or anxiety disorders during the 4-year follow-up (analysis 2: longitudinal).

    All analyses comprised three steps. Model 1 assessed the univariate associations of income and financial strain with depressive and/or anxiety disorders. In model 2, income and financial strain were included as main predictors. In model 3, we adjusted for sociodemographic characteristics (ie, age, gender, education level and partner status). Also, we checked if the presence of a lifetime diagnosis of depressive and/or anxiety disorder modified the association between financial strain and the onset/recurrence of depressive and/or anxiety disorders. This interaction was not significant (p>0.10) so results were not stratified. Furthermore, no significant interaction effect was found for financial strain and income in analysis 1 and analysis 2.

    Results

    Cross-sectional analysis

    Baseline characteristics

    At baseline of the sample of 2937 participants with all relevant data, 308 participants (10.5%) had a current depressive disorder, 553 participants (18.8%) had an anxiety disorder and 571 participants (19.4%) had both a depressive and anxiety disorder. Sociodemographic and financial characteristics of participants at baseline are shown in table 1. Mean age was 41.9 (SD=13.0) years and 66% of the participants were female.

    View this table:
    Table 1

    Baseline characteristics of participants according to psychiatric status at baseline (n=2937)

    Financial strain and income at baseline were negatively but not strongly correlated (r=−0.41, p<0.001). Correlations between financial strain and income were not different for participants with a current depressive and/or anxiety disorder compared with participants without a depressive and/or anxiety disorder at baseline. Participants with mild financial strain or severe financial strain reported lower income (median €1700 and €1300 /month, respectively) than participants with no financial strain (median €2700/month).

    Associations between financial strain and prevalence of depressive and/or anxiety disorders

    Participants with financial strain were more likely (table 2) to have a depressive and/or anxiety disorder at baseline, compared with participants with no financial strain (mild financial strain: OR=1.68, 95% CI 1.35 to 2.09; severe financial strain: OR=3.88, 95% CI 2.58 to 5.81). Also, compared with healthy controls, participants with mild or severe financial strain had higher odds of being remitted at baseline than participants with no financial strain (table 3: OR=1.56, 95% CI 1.24 to 1.97; OR=1.96, 95% CI 1.25 to 3.07, respectively).

    View this table:
    Table 2

    Association between depressive and/or anxiety disorders, financial strain and income at baseline for current patients versus healthy controls (N=2937)

    View this table:
    Table 3

    Association between depressive and/or anxiety disorders, financial strain and income at baseline for remitted patients versus healthy controls (N=2937)

    Associations of financial strain with depressive and/or anxiety disorders remained while taking income into account. Furthermore, post hoc subgroup analyses in which associations between financial strain and depressive and/or anxiety disorders were stratified according to income showed positive associations in all three income groups. Regardless of income level, participants with mild or severe financial strain were more likely to have a depressive and/or anxiety disorder at baseline compared with participants with no financial strain.

    Additional post hoc multinomial regression analysis (results not in table) indicated that the association with financial strain was stronger for having both a depressive and an anxiety disorder (mild financial strain: OR=1.40, 95% CI 1.11 to 1.77; severe financial strain: OR=3.59, 95% CI 2.60 to 4.96) than for depressive disorder only (mild financial strain: OR=1.17, 95% CI 0.88 to 1.56; severe financial strain: OR=2.11, 95% CI 1.39 to 3.20) or anxiety disorders only (mild financial strain: OR=1.29, 95% CI 1.03 to 1.61; severe financial strain: OR=1.83, 95% CI 1.28 to 2.62).

    Longitudinal analysis

    During the 4-year follow-up, 402 of the 1250 participants (32.2%) without a current depressive and/or anxiety disorder at baseline experienced a depressive and/or anxiety disorder: 13.5% experienced a depressive disorder, 7.9% experienced an anxiety disorder and 10.7% of participants experienced both a depressive and anxiety disorder.

    Associations of financial strain with the 4-year onset/recurrence of depressive and/or anxiety disorders

    Participants who reported mild or severe financial strain at baseline were not more likely to become depressed or anxious during follow-up, compared with participants without financial strain (table 4: OR=1.08, 95% CI 0.83 to 1.42; OR=1.05, 95% CI 0.64 to 1.73, respectively). Income was, however, negatively associated with the onset/recurrence of depressive and/or anxiety disorders (OR=0.87, 95% CI 0.78 to 0.97). After adjusting for sociodemographic characteristics, this association was no longer statistically significant (p=0.065). Post hoc analysis in which results were stratified according to three income levels showed comparable results: financial strain was not related with the onset/recurrence of depressive and/or anxiety disorders in either income category.

    View this table:
    Table 4

    Associations of financial strain and income with the onset/recurrence of depressive and/or anxiety disorders during the 4-year follow-up (n=1250)

    We reran the analyses for the 2-year outcomes and found comparable results: The final model showed that participants with mild or severe financial strain at baseline did not have higher odds of becoming depressed or anxious during the 2-year follow-up (OR=1.14, 95% CI 0.85 to 1.53; OR=1.13, 95% CI 0.66 to 1.93, respectively). Again, the association between income and the onset/recurrence of depressive and/or anxiety disorders was not significant (OR=0.90, 95% CI 0.79 to 1.03).

    Discussion

    Main findings

    We examined associations of financial strain and income with the prevalence and onset/recurrence of depressive and/or anxiety disorders in a large multisite cohort. The results indicated that financial strain and income were cross-sectionally associated with depressive and/or anxiety disorders (hypothesis 1). This is consistent with previous studies.2–4 ,6 ,9 ,13 However, financial strain and income were not related with the onset/recurrence of depressive and/or anxiety disorders during the 4-year follow-up. Hence, hypothesis 2 was not accepted. Previous research showed mixed results of the impact of financial strain on the onset of depressive and anxiety disorders. For example, Wang et al6 found that financial strain was associated with an increased risk of a depressive disorder for participants who worked in the past 12 months,i while Butterworth et al9 found no effect of financial strain after adjusting for depressive symptoms at baseline. Conversely, a cohort-study in the UK10 indicated that financial strain was independently associated with both onset and persistence of common mental disorders at 12-month follow-up. Moreover, post hoc sensitivity analyses, in which employment status at baseline was included in the model, showed that employment status at baseline had no effect on the association between financial strain and the presence and onset/recurrence of depressive and/or anxiety disorders (ie,<10% change in the regression coefficient of the effect of financial strain on depressive and/or anxiety disorders), although the employment status differed considerably according to psychiatric status at baseline.

    Although financial strain was cross-sectionally associated with depressive and/or anxiety disorders, according to our findings it does not predict the onset/recurrence of depressive and anxiety disorders. An explanation may be that a different type of relationship is involved, that is, instead of a causal effect of financial strain on depressive and/or anxiety disorders, there may be reverse causation which postulates that participants might experience more financial difficulties as a result of their depressive and/or anxiety disorder. For instance, participants with a depressive and/or anxiety disorder are a vulnerable group on the labour market; they might become unemployed more easily, might be discriminated in job interviews or might have had fewer career opportunities.16 ,17 This unfavourable position on the labour market also manifested in our study; participants with a depressive and/or anxiety disorder were more often unemployed than participants without a depressive and/or anxiety disorder. Furthermore, depressed or anxious participants could be more prone to worry about their financial status. Second, our findings might be explained by the large time interval in which the effect of baseline financial strain on depressive and/or anxiety disorders was assessed. The effect of financial difficulties on depression fades over time, unless the financial difficulties persist.9 ,18 The association between depression and financial strain will, therefore, decline as the interval between the measurements increases. It might also explain differences in findings between studies. Our study and studies by Butterworth et al8 and Wang et al6 used a follow-up of 4–6 years, while Weich and Lewis’ study10 used a 1-year follow-up. However, we checked the association between financial strain and the onset/recurrence of depressive and/or anxiety episodes for the 2-year data and found comparable results.

    Furthermore, this study examined whether the associations of financial strain with the prevalence and onset/recurrence of depressive and/or anxiety disorders were above the effect of income (hypotheses 2 and 4). Hypothesis 2 was confirmed: the association between financial strain and having a depressive and/or anxiety disorder held after adjusting for income. Additionally, financial strain and income were only moderately correlated. Financial strain and income appear to be separate constructs. Since financial strain and income were not related with onset/recurrence of depressive and/or anxiety disorders, no conclusions could be drawn about the effect of financial strain over and above the effect of income; therefore, hypothesis 4 could not be accepted.

    Strengths and limitations

    The first strength of this study is the large naturalistic cohort-study among almost 3000 participants (NESDA), on which data the current study reports. This sample consists of persons with a current depressive and/or anxiety disorder, a history of depressive and/or anxiety disorder or at risk because of a family history, and healthy controls. Participants were selected from general population, general practices and mental health organisations. It, therefore, reflects various settings and developmental stages of psychopathology. Furthermore, the attrition rate of NESDA was relatively low: 85% of eligible participants at baseline participated in the 4-year follow-up assessment, while 81% provided all required data.

    A second strength is that onset/recurrence of depressive and/or anxiety disorders were assessed during the whole 4-year follow-up period by combining data from the 2-year and 4-year follow-up assessments. It is, therefore, unlikely that cases of depressive and/or anxiety disorder were missed. Other studies6 ,9 ,10 did not cover the entire follow-up period, which may have caused biased results for cases of depressive and/or anxiety disorders may be missed. Also, the second analysis primarily focused on onset/recurrence of new depressive and/or anxiety disorders by excluding participants who were depressed at baseline. Third, subjective and objective indicators of participants’ socioeconomic status were used so that their associations with depressive and/or anxiety disorders could be compared.

    A limitation is that financial circumstances were only assessed at baseline. A change in financial strain or income during the 4-year follow-up could not be determined. According to Lorant et al,5 a change in socioeconomic status was associated with a change in depressive symptoms and depressive disorders. Butterworth et al9, for example, found that although participants who experienced financial strain at baseline did have elevated risk of depression after 4-year follow-up, participants who experienced financial strain more recently had greater risks of being depressed after follow-up. These findings might explain why we only found a cross-sectional association of financial strain with depressive and/or anxiety disorders and no association with onset/recurrence of depressive and/or anxiety disorders during the 4-year follow-up.

    Another point of consideration is the combining of onset and recurrence of depressive and/or anxiety disorders into one variable in the longitudinal analysis instead of treating these separately. Assessing onset and occurrence separately, however, would have decreased our sample size considerably and would have had a negative impact on the robustness of our analyses since, for instance, the number of participants with (severe) financial strain who became depressed or anxious during follow-up would be too small. Besides, we found that presence of a lifetime depressive or anxiety disorder did not significantly modify the association between financial strain and depressive and/or anxiety disorders.

    Implications and further research

    This study showed, not unexpectedly, that persons who experience financial strain have higher odds of being depressed or anxious. This may have implications for mental healthcare services and social services. Perhaps even more attention should be paid to this association so that depressed or anxious patients who experience financial strain, regardless of their income level, can get more support. A treatment programme to target specific high-risk groups for financial strain and depressive and/or anxiety disorder might be an important innovation.

    The current study did not find significant associations of financial strain and income with the onset/recurrence of depressive and/or anxiety disorders during the 4-year follow-up. However, a meta-analysis3 suggested that in persons with low socioeconomic position, persisting depression may be a bigger problem than new depression. Further research could, therefore, explore the impact of financial strain and income on the persistence of depressive and/or anxiety disorders. Also, more longitudinal cohort-studies that investigate financial characteristics and mental disorders repeatedly are needed to study the question of causality. It is not yet fully clear whether financial difficulties predict mental disorders, whether mental disorder predicts financial difficulties or whether there is a vicious cycle between financial difficulties and mental disorders.

    Conclusion

    Experiencing financial strain is associated with the presence of depressive and/or anxiety disorders, over and above the effect of income. This finding suggests that when a person experiences a depressive and/or anxiety disorder, a subjective indicator like financial strain should be taken into account besides an objective indicator like income. Financial strain and income, however, were not related with the onset/recurrence of depressive and/or anxiety disorders.

    What is already known on this subject?

    • Low socioeconomic status is associated with higher risk of mental health problems, such as depressive and anxiety disorders. Mostly objective indicators of socioeconomic status are used. Subjective indicators, like perceived financial strain, have been rarely used but might be a better predictor of depressive or anxiety disorders. The exact associations between perceived financial strain, objective indicators and depressive or anxiety disorders are, however, still not clear.

    What this study adds?

    • This study showed that perceiving financial strain is associated with having a depressive and/or anxiety disorder, regardless of income level. Both financial strain and household income were not related with the onset/recurrence of depressive and/or anxiety disorders.

    Acknowledgments

    SMAD-K drafted this paper which was added to and modified by KEMB-L, JCvdW, BWJHP and HWJvW. All authors read and approved the final manuscript.

    References

    1. ↵
      Statistics Netherlands, The Netherlands institute for Social Research. Poverty Survey 2013. Den Haag CBS/SCP. 2013.
    2. ↵
      1. Fryers T,
      2. Melzer D,
      3. Jenkins R
      . Social inequalities and the common mental disorders: a systematic review of the evidence. Soc Psychiatry Psychiatr Epidemiol 2003;38:229–37. doi:10.1007/s00127-003-0627-2
      OpenUrlCrossRefPubMedWeb of Science
    3. ↵
      1. Lorant V,
      2. Deliege D,
      3. Eaton WW, et al
      . Socioeconomic inequalities in depression: a meta-analysis. Am J Epidemiol 2003;157:98–112. doi:10.1093/aje/kwf182
      OpenUrlAbstract/FREE Full Text
    4. ↵
      1. Jenkins R,
      2. Bhugra D,
      3. Bebbington P, et al
      . Debt, income and mental disorder in the general population. Psychol Med 2008;38:1485–93. doi:10.1017/S0033291707002516
      OpenUrlPubMedWeb of Science
    5. ↵
      1. Lorant V,
      2. Croux C,
      3. Weich S, et al
      . Depression and socio-economic risk factors: 7-year longitudinal population study. Br J Psychiatry 2007;190:293–8. doi:10.1192/bjp.bp.105.020040
      OpenUrlAbstract/FREE Full Text
    6. ↵
      1. Wang JL,
      2. Schmitz N,
      3. Dewa CS
      . Socioeconomic status and the risk of major depression: the Canadian National Population Health Survey. J Epidemiol Community Health 2010;64:447–52. doi:10.1136/jech.2009.090910
      OpenUrlAbstract/FREE Full Text
    7. ↵
      1. Kosidou K,
      2. Dalman C,
      3. Lundberg M, et al
      . Socioeconomic status and risk of psychological distress and depression in the Stockholm Public Health Cohort: a population-based study. J Affect Disord 2011;134:160–7. doi:10.1016/j.jad.2011.05.024
      OpenUrlCrossRefPubMed
    8. ↵
      1. Weich S,
      2. Lewis G
      . Material standard of living, social class, and the prevalence of the common mental disorders in Great Britain. J Epidemiol Community Health 1998;52:8–14. doi:10.1136/jech.52.1.8
      OpenUrlAbstract
    9. ↵
      1. Butterworth P,
      2. Rodgers B,
      3. Windsor TD
      . Financial hardship, socio-economic position and depression: results from the PATH Through Life Survey. Soc Sci Med 2009;69:229–37. doi:10.1016/j.socscimed.2009.05.008
      OpenUrlCrossRefPubMedWeb of Science
    10. ↵
      1. Weich S,
      2. Lewis G
      . Poverty, unemployment, and common mental disorders: population based cohort study. BMJ 1998;317:115–19. doi:10.1136/bmj.317.7151.115
      OpenUrlAbstract/FREE Full Text
    11. ↵
      1. Penninx BWJH,
      2. Beekman AT,
      3. Smit JH, et al
      . The Netherlands Study of Depression and Anxiety (NESDA): rationale, objectives and methods. Int J Methods Psychiatr Res 2008;17:121–40. doi:10.1002/mpr.256
      OpenUrlCrossRefPubMedWeb of Science
    12. ↵
      1. Dunn N,
      2. Inskip H,
      3. Kendrick T, et al
      . Does perceived financial strain predict depression among young women? Longitudinal findings from the Southampton Women's Survey. Ment Health Fam Med 2008;5:15–21.
      OpenUrlPubMed
    13. ↵
      1. Okechukwu CA,
      2. El Ayadi AM,
      3. Tamers SL, et al
      . Household food insufficiency, financial strain, work-family spillover, and depressive symptoms in the working class: the Work, Family, and Health Network study. Am J Public Health 2012;102:126–33. doi:10.2105/AJPH.2011.300323
      OpenUrlCrossRefPubMed
    14. ↵
      1. Wittchen HU
      . Reliability and validity studies of the WHO—Composite International Diagnostic Interview (CIDI): a critical review. J Psychiatr Res 1994;28:57–84. doi:10.1016/0022-3956(94)90036-1
      OpenUrlCrossRefPubMedWeb of Science
    15. ↵
      1. Lyketsos CG,
      2. Nestadt G,
      3. Cwi J, et al
      . The Life-chart method to describe the course of psychopathology. Int J Methods Psychiatr Res 1994;4:143–55.
      OpenUrlWeb of Science
    16. ↵
      1. Waghorn G,
      2. Chant D
      . Work performance among Australians with depression and anxiety disorders: a population level second order analysis. J Nerv Ment Dis 2006;194(12):898–904. doi:10.1097/01.nmd.0000243012.91668.a5
      OpenUrlCrossRefPubMed
    17. ↵
      1. Edward KL,
      2. Munro I
      . Depression and other mental illnesses in the context of workplace efficacy. J Psychiatr Ment Health Nurs 2008;15(7):605–11. doi:10.1111/j.1365-2850.2008.01253.x
      OpenUrlCrossRefPubMed
    18. ↵
      1. Mirowsky J,
      2. Ross CE
      . Age and the effect of economic hardship on depression. J Health Soc Behav 2001;42:132–50. doi:10.2307/3090174
      OpenUrlCrossRefPubMedWeb of Science

    Footnotes

    • Funding The infrastructure for the NESDA study (www.nesda.nl) has been funded through the Geestkracht program of the Netherlands Organisation for Health Research and Development (Zon-Mw, grant number 10-000-1002) and participating universities (VU University Medical Center, Leiden University Medical Center, University Medical Center Groningen).

    • Competing interests None.

    • Ethics approval The research protocol was approved by the Ethical Committee of participating universities.

    • Provenance and peer review Not commissioned; externally peer reviewed.

    • ↵i Additional analysis showed that employment status did not interact with financial strain in the longitudinal analysis.