More than half of workers with depression do not seek treatment, according to a recent study.

Canadian researchers found that at as many as 40 percent of their study participants were experiencing significant depressive symptoms and, of that group, 52.8 percent did not recognize a need to seek help. Similar rates have also been observed in population studies in the United States and Australia.

"Our results suggest that a significant number of workers who are experiencing symptoms of depression do not recognize they could benefit from help, and so do not it," Dr. Carolyn Dewar, lead author of the study and head of CAMH's Centre for Research on Employment and Workplace Health, said in a statement. "This barrier has a significant impact on health and work productivity, and is an area where employers can focus efforts to reduce work productivity loss."

For the study, researchers collected and analyzed data from more than 2,000 Ontario adults who completed either a telephone questionnaire or a web-based survey. Participants were between 18-65 years old and had been in the workforce during the preceding 12 months.

As part of the study, researchers also developed a model to help employers identify key barriers to treatment.

"It's important for employers to know where to start when it comes to tackling productivity loss related to untreated depression," Dr. Dewar said. "Our study suggests that helping workers understand when they should be seeking help would significantly boost work productivity."

In addition to treatment need, researches also assessed attitudinal and structural barriers to accessing mental health services. Attitudinal barriers include stigma of mental illness and belief that treatment is ineffective. Structural barriers include financial limitations and difficulty accessing appropriate mental health care. When all three types of barriers were removed, researchers found that loss of work productivity was reduced by nearly 50 percent.

"Improving recognition for treatment is not the only opportunity for employers," Dr. Dewar said. "The most effective workplace mental health strategies will acknowledge the complexity of the problem and address all aspects in a comprehensive way."

The findings are detailed in the Journal of Occupational and Environmental Medicine.