Is women’s mental health more susceptible than men’s to the influence of surrounding stress? Inger Sandanger1, Jan F. Nygård1 Tom Sørensen2 and Torbjørn Moum1 1
Department of Behavioural Sciences in Medicine
University of Oslo 2
Institute group of psychiatry, University of Oslo
Correspondence and request for offprints to Inger Sandanger E-mail:
[email protected]
Keywords: Depression, Anxiety, Sex, Life event stress, Work stress
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Abstract Background Most epidemiological population studies have demonstrated that women suffer more anxiety and depression than men. A higher level of stress, greater vulnerability to stress, and a non-additive effect of private/domestic and occupational obligations on women have been suggested as an explanation. Objective The objective of this study was to examine if women’s mental health are more susceptible than men’s to the influence of surrounding stress. Material and method A cross-sectional, random sample of the population resulted in 651 men and 626 women, all of whom were employed, participating in the study. Participants were interviewed using face-to-face standardized questionnaires. Results Younger women experienced more stressful relationship events, illness events and network events than men of the same age. Relationship events were more important for men as they grew older, and interacted with other stress to increase anxiety and depression symptoms. Stressful illness events were stronger related to anxiety/depression symptoms in women over 40 than in men of the same age, and interacted with work stress to increase symptom scores. Conclusion Stress was more strongly related to symptoms in women, suggesting that they may have a greater susceptibility to surrounding stress, and to somatic illness stress. This might contribute to the sex difference in psychiatric illness.
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Introduction Most epidemiological population studies have demonstrated that women suffer more anxiety and depression than men [1-4]. Geographical differences in psychiatric symptoms have been mainly due to differences in the female part of the sample [5, 6]. Even seasonal variations in psychiatric symptoms have been found to be due to differences among the women [7]. These findings indicate that the relationship between psychiatric symptoms and the environment is most prominent in women. However, differences in mental health have been less prominent when comparing men and women who are employed, than between employed men and women homemakers [8]. Therefore, differences in mental health have also been attributed to role differences [9, 10]. An association between exposure to stressful life events and subsequent onset of depression has consistently been demonstrated, with the strength of this association illustrated by a dose – response relationship [11]. Negative relationship events might be more important to women’s health. In particular, the assumption that women are more involved in their social network and pay an emotional price for it has been supported [8]. In one large study, the female predominance of mental disorders was obvious only in the presence of physical illness [12] implying that physical illness might be the reason for sex differences in anxiety and depression symptoms. Chronic physical conditions have been found to lead to depression [13]. Supporting this, several studies have demonstrated that women visit doctors more frequently than men [14, 15] and have higher rates of somatic illness [16]. In the occupational sphere, women have been found to perceive more job demands [17]. Low control of work, as well as little autonomy in the working situation [18] and skewed negative balance between work effort and reward [19] have been found to result in health problems. In addition, factors from the physical environment have been shown to affect the psychological well-being of office workers [20]. Organisational and extraorganisational factors affect stress, employee well3
being, and absenteeism more among women than men [21]. Private and occupational stress can influence each other by altering the effect of each of them [22]. Given that women are more vulnerable to stress or to combinations of stress from different arenas, the associations between stress or certain stress combinations and symptoms should be stronger in women than in men. And if so, stress may be a contributor to the higher psychiatric illness in women. Objective The objective of this study was to examine if women’s mental health were more susceptible than men’s to the influence of surrounding stress. This was done by firstly comparing the levels of reported stressful life events and work stress in the sexes, secondly, by examining the sex differences in associations between these stresses, alone and in combinations, and symptoms of anxiety and depression, and if these association were different at different ages.
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Methods Design Data regarding anxiety and depression symptoms and stress were gathered by personal interviews in a random, cross-sectional, individual sample of the general population at two sites in Norway (Oslo and Lofoten) during 1989–1991. Study population Of 3656 individuals (aged ≥ 18 years) selected by the Central Bureau of Statistics, 929 persons were excluded from the study because they were deceased, had moved, or were impossible to locate after at least 12 attempts. Personal contact was established with 2727 individuals, of whom 2015 were personally interviewed, which resulted in a response rate of 74%. The sex and age composition of the sample was similar to the source population. From these 2015 persons, all persons who were employed for at least 10 hours per week were included, totalling 651 men and 626 women. Concepts and operationalizations The response variate anxiety and depression symptoms was conceived as a continuum of symptoms, present at some level in every individual, which is considered an illness when exceeding a certain level. It was operationalized using the 25 questions regarding anxiety and depression that had occurred the week before the interview in the Hopkins Symptoms Checklist 25 (HSCL-25), which the respondent completed as a pencil-and-paper scheme. Each item was scored for both its presence and intensity, which was assessed on a scale from 1 (not bothered at all) to 4 (extremely bothered). The sum score divided by number of items answered provided an overall score from 1.00 to 4.00 [23-25]. Stressful life events were reported retrospectively for the 12 months preceding the interview, and included both acute events and more enduring chronic strains [26]. They were assessed from a life event list of 40 negative events [27] not including those that were related to work environment. 5
Based on the theories mentioned in the introduction about sex differences in the meaning and significance of relationships, physical illness and social network, the events were separated into four indices, according to their content: relationship events, illness events, network events, and external events (see Table 1). Each of the four indices was made by adding the number of reported events over the preceding 12 months. Work stress was recorded as the current level of work stress, and three indices were constructed from 14 single items, covering: 1) psychological stress in the working situation, 2) organisational stress, and 3) physical stress at work. The 14 items were subjected to a factor analysis with oblimin rotation, which confirmed the indices. The standardized factor scores, plus 10, were used in the analyses. The item “high speed” loaded on both the psychological stress index and the physical stress index, whereby it was decided to load it onto the latter. Questions regarding stress were asked verbally. Difficulties with changing place of work (no, rather difficult, difficult) and why (the children, difficulties getting other work here, other) was recorded. Occupation was recorded with job title and classified according to Nordic classification of occupation [28]. Age was analysed as a dichotomous variate, dividing participants into those older than 40 years of age and participants who were 40 or younger. Age was also used as a continuous variate within the strata. Sex and being married/cohabitant were used as a dichotomy, with “1” representing a married woman. Years of education were categorized as
