Job control has been a key concept in research on the psychosocial work environment and employee health for decades. A general hypothesis is that the more job control employees have, the lower their risk of stress-related diseases. 

However, the evidence to date has been inconclusive. The two components of job control, skill discretion and decision authority, may be differentially associated with health, which is a possible explanation for previous mixed findings. Therefore, this study examined the longitudinal associations of job control and its components separately, along with mental health and incident cardiovascular disease in large prospective cohorts with up to 20 years of follow-up. 

The analyses showed that skill discretion and decision authority had different, to some extent opposite and subgroup specific associations with mental and cardiovascular health. Furthermore, contrary to previous understanding, high decision authority was found in some circumstances to associate with an increased risk of mental disorders and cardiovascular mortality. Job control appears to be an equivocal concept in terms of health risk.