issues cost Australian employers over $10 billion per year,13
which is consistent with international literature that recog-
nizes the significant indirect costs of workplace mental health
that are associated with reduced productivity, absenteeism,
and staff turnover.14,15 Further, Birnbaum and colleagues8
reported that disability costs for depressed workers were 4.5
times greater than those for nondepressed employees.
Previous studies have consistently demonstrated that
certain job factors, specifically those associated with high
demand and low control, greatly increase the risk of mental
illness, including anxiety and depression.16–18 For example,
Karasek16 and Siegrist19 developed a model showing that an
imbalance between the mental effort expended for work and
the recognition and rewards received was linked to a variety
of mental and physical problems. Further, Kelloway and