Work and mental health: the experience of the Quebec workforce between 1987 and 1998.

This study examines the distribution of psychological distress in twelve occupational groups over the decade 1987-1998 in the Quebec workforce. Cross-sectional data from the three phases of the Quebec Health and Social Survey are used with n = 9,450 in 1987, n = 10,947 in 1992 and n = 10,960 in 1998, totalling 31,357 workers aged 15 and over. Occupations are classified according to the Canadian Socio-economic Classification of Occupations. Prevalence estimates for occupational groups are computed and logistic regression analyses are conducted controlling for gender, age and marital status. The results show that the prevalence of workers with psychological distress increased sharply between 1987 and 1992 and declined back in 1998 but still increased compared to 1987. However, only non-qualified white collars, semi-qualified blue collars and male non-qualified blue collars show a significant increment in psychological distress over time. Analysis of the differentials in the prevalence of psychological distress gives greater odds of distress for supervisors, semi-qualified white and blue collar workers compared to upper managers. The odds for occupations are stable over time, gender, age and marital status. The odds of female workers significantly decreased in the three phases. It appears that the restructuring of the work environment and the perturbations in the larger society promoted an increase of psychological distress within definite segments of the workforce. The specific contribution of occupation is limited but supervisors and occupations requiring lower qualifications are more at risk regarding mental health at work.