Paternal psychosocial work conditions and mental health outcomes: A case-control study

The etiology and contributing factors of mental health problems are complex and multifaceted. Researchers have investigated a broad range of factors that may contribute to the development of mental health problems such as a family history of mental health problems and socio-demographic factors (e.g., ethnicity and marital status).

There is growing evidence that ethnicity and other parental characteristics may impact on child mental health outcomes through socialization practices (for a review see Hughes et al. [1]). For example, increasingly research is documenting that positive ethnic identity among minority children and adolescents functions as a protective factor for mental health and school outcomes, and it has been hypothesized that such protective effect is a function of socialization processes occurring between parents and children [2‐4].

While research on how specific ethnic socialization processes impact on child and adolescent outcomes is still needed, the role of the social and family environments in the development of mental health problems among the non-minority children and youth has been widely investigated. Theoretical models of developmental psychopathology have highlighted the importance of environmental stressors in the etiology of different mental health outcomes [5‐8]. Some of these stressors include acute traumatic events, chronic strain and adversity, and accumulation of stressful life events and daily challenges [7]. Some of the most notable environmental stressors that have been found to profoundly impact children and youth mental health are exposure to neighbourhood violence [9]; parental chronic illness [10‐13]; and poverty and economic hardship [12]. In addition, temporary or prolonged parental unemployment may add further stress in the form of increased parental alcohol intake, home violence and child abuse [13].

Research on the impact of unemployment on children's development has identified changes in parenting and marital relationships as the primary factors linked to children's socio-emotional functioning [14‐16]. Several studies originating in the Great Depression of the 1930s indicated that fathers were more susceptible than mothers of emotional instability as a consequence to major income family losses [17, 18]. Specifically, fathers tended to have increased anger and be more punitive in disciplining their children [15, 19, 20].

Parental socioeconomic difficulties due to prolonged unemployment or loss of income are also associated with increased addictive behaviours such as alcohol dependence and alcoholism, and family violence [13] which in turn increase the risk of children living in such family environments to develop poor mental and physical health in adulthood [21‐23]. Several studies postulated that the way in which socioeconomic hardship affects parenting styles, especially in fathers, functions as an important determinant of children's mental health outcomes and school related problems [24‐28].

As the effect of socioeconomic hardship and unemployment can be mediated through changes in parenting styles, adverse psychosocial work conditions experienced by employed fathers can also play a critical role in children's outcomes.

In addition to the specific type of employment, the degree to which fathers experience stress at the workplace can also contribute significantly to the quality of the family environment which is acknowledged as a critical determinant of children's outcomes.

Two studies have been conducted to date on the impact of psychosocial work conditions of employed fathers on children's outcomes. Steward and Barling [25] conducted a study with 189 grade 4 and 5 Canadian students and found that paternal psychosocial work conditions were associated with parenting behaviours and children's behaviour. Ostry and colleagues [29] conducted a study with 19,833 Canadian children of sawmill workers and found significant associations between suicidal behaviours and several psychosocial work conditions of fathers when their children were young or in their early adolescence.

These findings, in conjunction with epidemiological trends indicating that the onset of many mental health disorders occurs in childhood and adolescence [30‐35], emphasize the importance of understanding how exposure to paternal psychosocial work conditions in childhood influence mental health outcomes throughout the lifespan.

This study focuses on the investigation of the components of the job strain model [36], also known as the demand/control model, as determinants of mental health outcomes across four broad age groups spanning from childhood to adulthood. The demand/control model postulates that job strain occurs when workers are overloaded psychologically and at the same time they have no control over their work environment. This combination of high psychological demand and low control is hypothesized to increase the risk of stress related illnesses amongst the workers [37].

Here we hypothesize that paternal psychosocial work conditions play an important role in the onset of mental health problems and that, consistent with the literature on developmental psychopathology, paternal mental health and socio-demographic characteristics can be significant determinants of mental health condition from childhood to adulthood.

Therefore, the present study investigates the impact of paternal psychosocial work conditions on a broad range of mental health conditions in a cohort of children whose fathers were employed in a selected group of sawmills in British Columbia, Canada. In recognition of the importance of addressing mental health outcomes from a developmental perspective, we investigate the onset of mental health conditions in four different age groups: childhood and early adolescence, adolescence, young adulthood, and adulthood. Because the influence of stressors on mental health can change considerably from childhood to adolescence and throughout adulthood [38‐40] conducting separate analysis for these four groups has allowed us to investigate the specific effects of paternal psychosocial work conditions on mental health outcomes from a life-course perspective.

This study is based on a cohort of male sawmill workers (N = 28,794) for whom data on employment history, job mobility, and physical and psychosocial work conditions were obtained. The original cohort of sawmill workers was gathered in the mid 1990s in order to conduct an occupational study on the effects of chlorophenol anti-sapstain exposure among British Columbian sawmill workers. Fourteen sawmills located in British Columbia were identified and personnel records for workers who had worked in one of these mills for at least one year in the period between1950 and 1998 were accessed and reviewed. Personal identifying information for eligible workers and complete job history records were abstracted from personnel records (see Hertzman et al. [41] for a complete description of methods used to assemble the sawmill workers' cohort).

Using birth files from the British Columbia provincial vital statistics registry and BC Linked Health Data Base we identified the children born between 1952 and 2000 to the cohort of sawmill workers. Through these two linkages 37,827 children of sawmill workers were identified, forming an offspring cohort. This study focuses on the developmental psychopathology among the offspring cohort and its association with paternal psychosocial work conditions.

Figure 1 indicates that 67% of cases were identified by the age of 30, with young adulthood representing the developmental period with the greatest number of first time mental health diagnoses. The most prevalent diagnoses assigned to all age groups are depression (children/early adolescents – 33%; adolescents – 37%; young adults – 33%; adults – 31%), and neurotic disorders (children/early adolescents – 21%; adolescents – 20%; young adults – 20%; adults – 21%). Adjustment reaction was the third most prevalent diagnosis among children/early adolescents (20%) and adolescents (11%); and acute reaction to stress was the third most prevalent diagnosis among young adults (13%) and adults (13%).

Table 2 and Additional file 1, 2 and 3 show the results of the multivariate analyses for children/early adolescents, adolescents, young adults, and adults respectively.

Ethnicity of the father was often associated with mental health conditions from childhood through adulthood. Children of fathers of Sikh or Chinese origin were consistently at lower risk of being diagnosed with mental health conditions such as depression, neurotic disorders, adjustment reaction, acute reaction to stress, and non-dependent drug abuse. Ethnic origin was associated with different age groups depending on the specific mental health condition. For example, being of Sikh origin functioned as a protective factor against depression and neurotic disorders among children (neurotic disorder: OR = .193, p = .001, 95% IC = .075–.495; depression: OR = .184, p < .001, 95%CI = .090–.379) and adolescents (neurotic disorder: OR = .288, p < .001, 95% IC = .185–.447; depression: OR = .439, p < .001, 95%CI = .331–.581), but not among young adults (neurotic disorder: OR = .830, p > .05, 95% IC = .663–1.04; depression: OR = .870, p > .05, 95%CI = .731–1.04) and adults (neurotic disorder: OR = .1.05, p > .05, 95% IC = .657–1.68; depression: OR = .953, p > .05, 95%CI = .652–1.39); and being of Chinese origin functioned as a protective factor for depression (OR = .211, p < .001, 95%CI = .114–.393) and neurotic disorders among young adults (OR = .357, p = .001, 95%CI = .193–.661), and for adjustment reaction among adolescents (OR = .187, p < .05, 95%CI = .038–.930) and young adults (OR = .186, p < .05, 95%CI = .043–.807).

Worth of noting is that while the proportion of Chinese participants in our sample (approximately 1% or less of the general population) is representative of the British Columbia population the Sikh participants are overrepresented in our sample with approximately 13% of the participants versus the expected 3% in the general BC population [45].

Duration of employment was associated with depression among adolescents (OR = .964, p < .05, 95%CI = .937–.991), alcohol dependence among adults (OR = .931, p < .05, 95%CI = .883–.982), and non-dependent drug abuse among adults (OR = .924, p < .05, 95%CI = .871–.979): the longer the fathers were employed at one sawmill the less the risk of being diagnosed with each of these conditions.

Paternal psychosocial work conditions were also significant factors associated with all mental health conditions investigated. However, different sub-dimensions of psychosocial work conditions were associated with specific diagnoses across the different age groups (see Table 2 and Additional files 1, 2, 3): control was associated with adjustment reaction among adolescents (OR = .866, p < .05, 95%CI = .775–.967) and alcohol dependence among adolescents (OR = .770, p < .05, 95%CI = .536–.994); psychological demand was associated with neurotic disorders among young adult (OR = .702, p < .001, 95%CI = .568–.868); noise was associated with acute reaction to stress among adults (OR = 1.42, p < .05, 95%CI = 1.06–1.91); and social support was associated with non-dependent drug abuse among adults (OR = 1.95, p < .05, 95%CI = 1.12–3.42).

In this study we investigated whether paternal psychosocial work conditions played a role in developmental psychopathology among the children of a cohort of sawmill workers from British Columbia, Canada. The present study has generated some important findings that contribute to the literature on mental health and developmental psychopathology in different ways.

First, we found that ethnicity of the father was a significant predictor where the risk of being diagnosed with one of several mental health outcomes from childhood to adulthood was lower for children of Chinese of Sikh fathers. This finding is consistent with what we found among adult sawmill workers where mental health diagnoses were less likely to be observed among Sikh and Chinese workers [46]. This finding is also consistent with findings from studies on the role of ethnicity on child development indicating that positive ethnic identity among minority children and adolescents functions as a protective factor for mental health and school outcomes [2‐4].

Second, we found that the longer the fathers were employed at one sawmill the less the risk of being diagnosed with depression, alcohol dependence, and non-dependent drug abuse. This finding is consistent with the literature on unemployment and health in that is suggests that children may be affected by paternal unemployment and loss of income in important ways [24‐28].

Third, we found that the association between paternal psychosocial work conditions (that in most cases were measured years prior to the mental health diagnosis) and mental health outcomes could be different depending on the age cohort (e.g., whether it was the children's or the adult's cohort). For example, with the exception of adjustment reaction, parental psychosocial work conditions played a more important role in adolescence and adulthood than it did during childhood. In some cases, paternal psychosocial work conditions were associated with mental health diagnoses in adulthood and not in other age groups such as in acute reaction to stress and non-dependent drug abuse. These findings suggest that while paternal psychosocial work conditions are significantly associated with a number of different mental health diagnoses, their effects are generally more noticeable over the long term than in the immediate future.

To a certain extent the results reported in this study are consistent with findings of the developmental literature in that they provide further evidence of the significant impact of early influences on health and development from childhood throughout adulthood. However, these findings have some important elements of novelty, most notably the original evidence of the critical role that exposure to adverse paternal psychosocial work conditions play in the first sixteen years of life contributing to the onset of mental health outcomes in different age cohorts.

While this study used rigorous design and analytical strategies, there are some limitations that need to be mentioned. One limitation is related to the use of an administrative database instead of complete clinical records to infer diagnosis which can lead to misclassification bias. However, this potential bias may be minimized because we used a large number of participants. Another important limitation of the study is the possible bias linked to the expected co-morbidity in mental health and the fact that the same participants may have appeared twice or more in the analysis.

At the conceptual level, a greater issue that constitutes a potentially important limitation is linked to the historical challenge of defining mental health and the ways in which mental health manifests in minority cultures. In the present study mental health was implicitly defined according to the parameters of psychiatry and clinical psychology traditions embodied in the DSM IV (and reflected in the ICD9 codes) where 'mental disease' rather than 'mental health' is identified. This is a very important issue especially in light of fact that important associations between ethnic origin and several mental health diagnoses were here identified. Vega and Rumbaut [47] eloquently describe the important issues that influence the way minority mental health is investigated in North American societies. Specifically, they argue that one of the greatest challenges of contemporary researchers lies in their ability to disentangle cultural influences from more accurate measurement and understanding of psychiatric problems in minority cultures.

Despite the potential limitations of this study, the findings reported here are overall important in many respects. First, they contribute to the advancement of theories of developmental psychopathology by incorporating concepts from the occupational health literature (i.e., psychosocial work conditions) and generating discussion on ways in which these can be 'brought home' and turned into 'adverse childhood experiences'. Second, results of this study also add to the literature of the effect of parental unemployment on child development and specifically identify what sub-dimensions of psychosocial work conditions are the most probable to increase the risk for developmental psychopathology from childhood to adulthood. Third, findings from this study may also have important clinical implications by informing age specific intervention strategies and family therapy approaches where parents are offered support to cope with work stress and related occupational challenges.

By investigating several mental health outcomes of 19,833 children of sawmill workers from British Columbia, Canada we found that the degree to which children are exposed to adverse paternal psychosocial work conditions during childhood is associated with their mental health outcomes throughout adulthood. his study provides support to the tenet that being exposed to paternal work stress during childhood can have long lasting effects on the mental health of individuals.