Comparing sense of coherence, depressive symptoms and anxiety, and their relationships with health in a population-based study

https://doi.org/10.1016/j.socscimed.2008.01.053Get rights and content

Abstract

The strong negative correlations observed between the sense of coherence (SOC) scale and measures of depression and anxiety raise the question of whether the SOC scale inversely measures the other constructs. The main aim of the present study was to examine the discriminant validity of the three measures by comparing their associations with health indicators and behaviours. The participants were 25 to 74-year-old Finnish men (n = 2351) and women (n = 2291) from the National Cardiovascular Risk Factor Survey conducted in 1997. The SOC scale had high inverse correlations with both depression (r = −0.62 among both men and women) and anxiety measures (r = −0.57 among the men and r = −0.54 among the women). Although confirmatory factor analyses suggested that it was possible to differentiate between SOC, cognitive depressive symptoms and anxiety, the estimated correlations were even higher than those mentioned above. Education was related only to SOC, but the associations of SOC, cognitive depressive symptoms and anxiety with self-reported and clinically measured health indicators (body mass index, blood pressure, cholesterol) and health behaviours were almost identical. The variation in the lowest SOC tertile was more strongly associated with health variables than in the highest tertile. To conclude, the size of the overlap between the SOC and depression scales was the same as between depression and anxiety measures. This indicates that future studies should examine the discriminant validity of different psychosocial scales more closely, and should compare them in health research in order to bring parallel concepts into the same scientific discussion.

Introduction

Personality and emotional factors have long been suggested to have an influence on physical health. Research efforts have been directed to the negative emotions (e.g., hostility, depression, anxiety) hypothesized to affect disease onset and development (Suls & Bunde, 2005), as well as, positive psychosocial variables (e.g., optimism, social support, sense of coherence) that are assumed to maintain and enhance health. The tendency among researchers has been to evaluate the independent effects of different psychosocial factors on physical health, while ignoring possible overlap among variables (Kaplan, 1995). Sense of coherence (SOC) attracted a lot of attention after the development of a quantitative scale to measure it. Nevertheless, researchers such as Geyer (1997) have criticized the ambiguity of the scale and its lack of discriminant validity in relation to the measures of depression and anxiety.

Antonovsky, 1979, Antonovsky, 1987, Antonovsky, 1993 proposed a salutogenic orientation focusing on factors that protected individuals' health. He defined the central concept, SOC, as an orientation towards life that characterises the extent to which an individual appraises internal and external environments as (1) comprehensible, (2) manageable and (3) meaningful. Antonovsky (1987) developed these three interrelated dimensions and the SOC questionnaire on the basis of interviews with persons who had experienced severe trauma. He maintained that SOC has much in common with the psychological constructs of hardiness (Kobasa, 1982), locus of control (Rotter, 1966) and self-efficacy (Bandura, 1977).

The SOC scale exists in two forms: the original 29-item questionnaire and the shortened version including 13 items from the full form. Antonovsky, 1987, Antonovsky, 1993 designed each item to represent one of the three dimensions, but he emphasized that the scale measured the SOC construct unidimensionally. The structure of the SOC measure has since been investigated using both exploratory and confirmatory factor analysis, but with inconsistent results. Some studies employing exploratory factor analyses have supported the one-factor structure proposed by Antonovsky (e.g., Frenz, Carey, & Jorgensen, 1993), but other results have also been obtained (e.g., Sandell, Blomberg, & Lazar, 1998). Furthermore, a confirmatory factor analysis study on the 13-item SOC questionnaire conducted among Finnish working-aged people found support for the three-factor model (Feldt et al., 2006). Klepp, Mastekaasa, Sorensen, Sandanger, and Kleiner (2007), on the other hand, preferred the one-factor solution for a brief nine-item SOC scale because the factors in the two- and three-factor models were very strongly correlated, and the factor scores had similar correlations with measures of psychological well-being, depression and anxiety.

The SOC theory hypothesizes that an individual with a strong SOC maintains and enhances health through effective and flexible coping with stressors, such as by adopting health-enhancing and avoiding unhealthy behaviours (Antonovsky, 1987). An individual with a strong SOC is also more likely to perceive internal and social environments as non-stressful. SOC reduces the health-damaging effects of stress by lowering the probability of adverse physiological reactions and negative emotions associated with stress perceptions. Antonovsky (1987) emphasized that the consequences of stressors may be negative, neutral or positive, depending on their nature and the adequacy of coping. It is also possible that persistent or serious health problems may influence the development of SOC.

Numerous cross-sectional studies have found SOC to be positively associated with physical and psychological health (Flannery and Flannery, 1990, Larsson and Kallenberg, 1996, Lundberg, 1997, Pallant and Lae, 2002, Suominen et al., 1999), and health behaviours (e.g., alcohol problems and physical activity) (Kuuppelomäki and Utriainen, 2003, Midanik et al., 1992). There have been a few longitudinal studies investigating whether SOC predicts health outcomes (e.g., all-cause mortality and subjective state of health). Most of these have supported its predictability (Suominen et al., 2001, Surtees et al., 2003), but inconsistent results have also been reported. Kivimäki, Feldt, Vahtera, and Nurmi (2000) found in their study of municipal employees that SOC predicted sickness absence only among the women. Other research among people with chronic illness reported reciprocal causation between SOC and domains of health (Veenstra, Moum, & Roysamb, 2005). Overall, the SOC relationship with psychological well-being seems to be stronger and more direct than that with physical health (Eriksson & Lindström, 2006).

The conceptual and empirical relationship between depression and anxiety has been studied extensively, and the evidence suggests that it is difficult to differentiate these two constructs empirically. The emotion of fear has a central role in anxiety, which involves feelings of worry, apprehension and dread (Watson & Kendall, 1989). The essential characteristic of depression is sadness, with associated feelings of sorrow, hopelessness and gloom. Self-reported depression and anxiety have been highly correlated (typically between 0.45 and 0.75) in both psychiatric and non-psychiatric samples (Clark & Watson, 1991). Considerable co-morbidity has also been observed (Mineka, Watson, & Clark, 1998).

The strong relationship between depression and anxiety may reflect problems with existing scales and constructs. There is an overlap in many of the symptoms that define both syndromes, and many self-report scales also contain items that actually measure the other construct (Gotlib & Cane, 1989). Thus, Clark and Watson (1991) proposed a tripartite model of depression and anxiety: general distress or negative affect is common to both, while manifestations of low positive affect are specific to depression, and symptoms of somatic arousal signify anxiety.

The two best-known theories of depression are perhaps Beck, 1967, Beck, 1987 cognitive theory and Abramson, Metalsky, and Alloy's (1989) hopelessness theory. They both posit that cognitive vulnerability and negative life stress together precipitate depression. According to Beck (1987), dysfunctional attitudes involving feelings of loss, inadequacy, failure and worthlessness constitute cognitive vulnerability to depression, whereas in the view of Abramson et al. (1989), cognitive depression diathesis encompasses the general tendency to attribute negative events to stable and global causes, to infer negative consequences, and/or to infer negative characteristics about the self. In addition, Beck (1987) postulates that all depressed people show a cognitive triad: automatic thoughts reflecting negative views of the self, the world and the future. It is suggested that the degree of this negative thinking is directly related to the severity of other depressive symptoms.

The SOC construct could be integrated as a protective/risk factor into vulnerability-stress models of depression. Individuals with a strong SOC should be better able to maintain their emotional well-being in stressful situations, whereas those with a weak SOC share some of the cognitive vulnerability factors mentioned in Abramson et al.'s (1989) and Beck's (1967) theories. All this raises a question concerning vulnerability and protective factors in general: do they form different dimensions or are they merely opposite ends of a continuum? Antonovsky (1987) considered risk and protective factors qualitatively different. The SOC construct also shares similarities with cognitive and emotional features of depression, which raises the question of whether a weak SOC represents depression. Overall, SOC describes individuals' cognitive and emotional functioning on a more general level than theories of depression. In addition, the SOC theory is more oriented towards societal determinants (e.g., education) of health than depression theories. There is evidence that people in higher socio-economic positions have a stronger SOC (Lundberg & Nyström Peck, 1994).

High negative associations have been consistently observed between the SOC scale and measures of depressive symptoms and anxiety. In studies published between 1992 and 2003, the correlation coefficients between the scale and different measures of anxiety and depression varied from −0.29 to −0.82 and from −0.34 to −0.90, respectively (Eriksson & Lindström, 2005). Gruszczyńska (2006) calculated the mean weighted SOC correlations on the basis of 17 studies: −0.70 for anxiety and −0.65 for depression. The size of these correlations raises doubts about the construct validity of the SOC questionnaire. Thus, it has been proposed that rather than being a measure of resilience, the scale measures inversely negative affectivity/neuroticism (Frenz et al., 1993, Strümpfer et al., 1998, Watson and Clark, 1984).

There are a few studies that have investigated the relationships between SOC, anxiety, and depression. When confirmatory factor analysis was used, the 29-item SOC scale loaded on the same latent variable as the measures of trait anxiety, neuroticism, optimism, depression and self-efficacy (Gruszczyńska, 2006), and also on both the health-proneness and negative-affect factors (Kravetz, Drory, & Florian, 1993). Feldt, Metsäpelto, Kinnunen, and Pulkkinen (2007) found that a high SOC (measured on the 13-item questionnaire) was strongly associated (r = −0.86) with reversed neuroticism in their confirmatory model. Korotkov (1993) concluded from his four-week prospective study that the 13-item SOC instrument lacked face, construct and predictive validity, and that most of the items measured emotionality (neuroticism) rather than SOC. Meanwhile, Breslin, Hepburn, Ibrahim, and Cole (2006) recently analysed the longitudinal relationship between psychological stress and the 13-item SOC scale, and found that the stable components of distress and SOC were strongly inter-correlated (r = 0.86). On the other hand, Strümpfer et al. (1998) conceptualised the low end of negative affectivity as emotional stability, and interpreted the strong negative associations between both versions of the SOC instrument and the negative-affectivity scales as supporting the validity of the instrument. However, the SOC measures were more strongly associated with negative than with positive emotionality.

In sum, the few previous studies focusing on the relationship between the SOC scale and measures of negative emotions have yielded inconclusive results. SOC, depressive symptoms and anxiety have all been related to various health indicators and behaviours, but to our knowledge their associations with health-related variables have not been compared in any previous study. The purpose of the present study therefore was to investigate the discriminant validity of the SOC, depression and anxiety scales in a population-based sample. In more specific terms: (1) first, we examined the strength of the correlations between the measures of SOC, depressive symptoms and anxiety, and confirmed these with a confirmatory model that takes measurement error into account. (2) Our main aim was to assess the discriminant validity between SOC, depression and anxiety scales by comparing their associations with subjective and objective (body mass index, blood pressure, total cholesterol) health indicators, health behaviours and sociodemographic factors. If the SOC scale and the measures of depressive symptoms and anxiety are distinct measures, they should also be differentially related to other variables. (3) Finally, we wished to find out whether variation in the SOC was more strongly related to health variables at the high or low end of the distribution. The questionnaire produces variation among individuals with a weak and a strong SOC. Most depression inventories, on the other hand, do not account for variation among the non-depressed as they assess only the intensity of depressive symptoms. Antonovsky specifically hypothesized that a strong SOC, and not just the absence of weak SOC, protected health. If variation at the high end were associated with health measures, then this would give the SOC scale an advantage over depression measures.

Section snippets

Participants

The participants comprised a random sub-sample of the national cardiovascular risk factor survey (FINRISK) conducted in Finland in 1997 (Vartiainen et al., 2000). FINRISK 97 covered a random sample of 11,500 people aged 25–74 drawn from the Finnish population registers in five areas, (1) North Karelia Province, (2) Kuopio Province, (3) South-Western Finland, (4) the cities of Helsinki and Vantaa in the capital area, and (5) the northern province of Oulu. The sample was stratified according to

Results

Table 1 presents the descriptive statistics for SOC, depressive symptoms, anxiety and sociodemographic factors, and the Pearson correlations between these variables separately for men and women. Correlation coefficients of less than 0.10 were not considered noteworthy, although they became statistically significant due to the large sample size.

The mean age was 51.3 years (SD = 13.8) for the 2065 men and 47.1 years (SD = 12.7) for the 2002 women (Table 1). The SOC mean score was 65.6 (SD = 11.8) among

Discussion

We found strong relationships between the SOC scale and measures of depressive symptoms and anxiety in a representative population sample of 25 to 74-year-old Finnish people. These associations became stronger when we applied structural equation modelling, which takes measurement error into account. The main aim of our study was to examine the discriminant validity between the SOC, depression and anxiety scales by comparing their relations with health-related and sociodemographic variables.

References (50)

  • L.Y. Abramson et al.

    Hopelessness depression: a theory-based subtype of depression

    Psychological Review

    (1989)
  • A. Antonovsky

    Health, stress and coping

    (1979)
  • A. Antonovsky

    Unraveling the mystery of health: How people manage stress and stay well

    (1987)
  • A. Bandura

    Self-efficacy: toward a unifying theory of behavioral change

    Psychological Review

    (1977)
  • A.T. Beck

    Depression: Causes and treatment

    (1967)
  • A.T. Beck

    Cognitive models of depression

    Journal of Cognitive Psychotherapy

    (1987)
  • A.T. Beck et al.

    An inventory for measuring depression

    Archives of General Psychiatry

    (1961)
  • F.C. Breslin et al.

    Understanding stability and change in psychological distress and sense of coherence

    Journal of Applied Social Psychology

    (2006)
  • L.A. Clark et al.

    Tripartite model of anxiety and depression: psychometric evidence and taxonomic implications

    Journal of Abnormal Psychology

    (1991)
  • J. Cohen et al.

    Applied multiple regression/correlation analysis for the behavioral sciences

    (1983)
  • S. Cohen et al.

    Pathways linking affective disturbances and physical disorders

    Health Psychology

    (1995)
  • M. Eriksson et al.

    Validity of Antonovsky's sense of coherence scale: a systematic review

    Journal of Epidemiology & Community Health

    (2005)
  • M. Eriksson et al.

    Antonovsky's sense of coherence scale and the relation with health: a systematic review

    Journal of Epidemiology & Community Health

    (2006)
  • T. Feldt et al.

    Structural validity and temporal stability of the 13-item sense of coherence scale: prospective evidence from the population-based HeSSup study

    Quality of Life Research

    (2006)
  • T. Feldt et al.

    Sense of coherence and five-factor approach to personality

    European Psychologist

    (2007)
  • Cited by (79)

    View all citing articles on Scopus

    Support to conduct this research was provided by the Signe and Ane Gyllenberg Foundation.

    View full text