The scientists analyzed data from the bigger study conducted by the state of Ohio for the U.S. Bureau of Labor Statistics starting in 1979 that included information on job satisfaction. The scientists followed the job trajectories of study participants from the time they were 25 until age 39, dividing them into 4 groups: consistently lower job satisfaction, consistently high job satisfaction, people whose satisfaction started low but then trended higher, and people who started high but declined over the years.
The lead author of the study Jonathan Dirlam, a doctoral student in sociology, says: “We found that those with lower job satisfaction levels throughout their late 20s and 30s have worse mental health compared to those with high job satisfaction levels. Those who initially had high job satisfaction but downwardly decreased over time also had worse health.”
More detail here.