The study among permanently employed individuals in their early middle age showed, first, that there is a cross-sectional association between locked-in situation and poor mental health; second, that those who reported feeling locked-in at age 30 tended to have poor mental health even before entry into the labour market at age 16; third, that there is a gradient in the level of mental health in relation to the locked-in history during the life course from age 30 to age 43; fourth, that getting out of a locked-in situation is associated with improving and becoming locked-in is associated with worsening mental health; fifth, that these associations are gender-independent; and sixth, that the worsening is more pronounced and the improvement less pronounced in white-collar employees.
As regards the first finding, the study confirmed the hypothesis and also was in line with earlier knowledge (10, 14) of the association between feeling locked-in and poor mental health. It is noteworthy that the magnitude of the differences is quite uniform: irrespective of the age and the outcome, the scores of the locked-in are about a third higher. Table 1 also demonstrates the ‘natural’ phenomenon that somatic symptoms tend to become more common with age.
The second finding adds a novel life-course approach to the body of research. It demonstrates the importance of prior poor mental health for getting into a locked-in situation, and similar results with DSS and FSS indicate that this is due to selection rather than due to locked-in perception as a symptom of depression (i.e. the common methods bias). The finding of relatively steeply worsened mental health among the locked-in at age 30 suggests, however, that there might be a causal association from locked-in situation to poor mental health.
In line with earlier research (4, 15), the third and the fourth finding support the interpretation of such causality. Notably, however, the higher symptom scores at age 30 of the late group compared to the never group may indicate that there is health-related selection into a locked-in situation also in early middle age.
The fifth finding does not support our hypothesis of stronger associations among men. In line with corresponding finding of the association between unemployment and health (25), the present study adds to the evidence on gender independent stressfulness of the Swedish work life.
The sixth finding of a socioeconomic difference in the effects may reveal that in blue-collar employees the prospects for getting out of their current situation are imaginary, whereas in the white-collar employees the discrepancy between being locked-in and career ambitions is more concrete.
Locked-in is basically a theoretically constructed concept, and in order to study it empirically, the ‘latent variable’ needs to be worded into questions. Different questions have been developed. Stengård et al. (4), for instance, use the question about perceived employability (‘How easy would it be for you to get another similar job without having to change residence?’) and about workplace non-preference (‘Is the company/workplace where you work today the place you wish to work at in the future?’) to create the measure. The question used by Furåker et al. (17) (‘In general, what do you think of your chances at present of finding another job which is equal to or better than your current job?’) also refers to employability. In the study by Canivet et al. (15), in contrast, the focus is on non-desired occupation (‘Is your current occupation the occupation you would like to work at in the future’). The wording of our question (‘Are you doing what you preferably would like to do?’) is quite generic, and also the variable embraces all aspects of work life, i.e. current labour market status as an employee, current workplace (employer, job contents), current occupation and current career status. The overarching question is a strength; on the other hand it gives us reason to recommend that the contents of the locked-in concept as well as the questions should be elaborated further.
To be permanently employed at age 30 in 1995 when – in the wake of the deep recession at the beginning of the decade – the unemployment rate continued to be high (26), is evidence of good employability, and also relatively good (mental) health. On the other hand, the tough competition in the labour market may have forced several employees to accept ‘locked-in jobs’. Nevertheless, although the proportion of those feeling locked-in was smaller in 2007, in the last year of the decade-long macroeconomic growth with remarkably lower unemployment, the associations of feeling locked-in with poor mental health were equally strong as in 1995. In the other words, the association seems to be quite context-insensitive, both in terms of the life course and in terms of the historical time as indicated by the macroeconomic fluctuations.
The long follow-up, associated with high response rates, is a definite strength of this study. Regarding labour market attachment, the life course from age 16 to 21 is inherently unstable, and also being locked-in, elicited as we did here, may refer to diverse situations (student, temporary employment, unemployment, military service etc.), whereas by age 30 the labour market status is commonly established (63% of the total of 1001 respondents were permanent employees and 5% were entrepreneurs). By age 43 the corresponding figures had risen to 72% and 12%. Thus, we can argue that, in addition to answering the locked-in questions with reference to a homogeneously stable contractual status, our sample represents the core of the labour force. Due to the high response rate, the sample also includes the individuals with poor mental health who tend to be overrepresented among the non-respondents. In general, the Northern Swedish Cohort has been shown to be representative of Sweden as a whole in relation to demographics, socio-economic status and health complaints (21).
Although poor health could be assumed to cause job insecurity (27) more often than leading to a locked-in situation, the present study suggests that health-related selection also could exist. This topic should be studied in more detail. Another topic requiring further research, perhaps with qualitative data, is the class hypothesis that received support in this study.