Working the night shift may have different effects on male and female police officers’ mental health, new research shows.

While policewomen with depressive symptoms were more likely to have suicidal thoughts if they worked during the day than if they worked at night, policemen with symptoms of post-traumatic stress disorder (PTSD) thought of suicide more often when they worked more afternoon hours, Dr. John M. Violanti of the State University of New York at Buffalo and colleagues found.

Work schedules that disrupt normal sleep-wake cycles have been linked to depression, fatigue, and other health problems, Violanti and his team note in the American Journal of Industrial Medicine. Police officers must work in shifts and are known to be at greater risk of suicide and PTSD than the general population, they add.

To investigate whether shift work might influence the likelihood that a police officer would experience thoughts of suicide (suicidal ideation) and determine how pre-existing depression and PTSD might influence that relationship, Violanti and his team evaluated 70 male and 41 female police officers.

Most of the subjects were white (70 percent), had some college education (81 percent) and were married (64 percent). The average age was 44 years or younger. By reviewing 5 years of payroll records, the researchers noted how much of each officer’s time was spent working different shifts.

For policewomen with depressive symptoms, the researchers found the likelihood of suicidal ideation rose steadily with the percentage of total hours worked during the day. Specifically, the “prevalence of suicidal ideation increased by 116 percent for every 10-unit increase in percentage of hours worked on day shift, Violanti’s group reports.

The prevalence of suicidal ideation among the women also increased with age and time on the force.

Policemen with more PTSD symptoms were more likely to experience suicidal ideation if they worked more hours in the afternoon, but at a much lower rate compared with the women. For the men, the “prevalence of suicidal ideation increased by 13 percent with every 10-unit increase in the percentage of hours worked on afternoon shift.”

The investigators also found that suicidal ideation significantly decreased among the men as educational level increased. A similar trend was found among the women, but it was not statistically significant.

Overall, the prevalence of suicide for policemen and policewomen was 23 and 25 percent, respectively, about twice as high as that of the general population, at about 13.5 percent. Alcohol did not appear to influence suicidal ideation.

The male-dominated nature of police work could help explain the findings, Violanti noted in an interview. “There’s something about women being exposed to that organizational culture of policing, being exposed to the public in the daytime, it’s more difficult because it’s basically a male occupation,” he said. Women working day shifts who have children must find someone to look after them during the day, which can also be stressful.

On the other hand, he added, policemen may have a harder time when they are isolated from their male colleagues.

Disruptions due to shift work are likely to get worse, given that more and more police departments are moving toward 12-hour shifts, said Violanti, himself a retired New York State police officer. Officers prefer this type of schedule because it gives them more days off, he explained, and departments like them because they allow more efficient operation.

Officers who work nights often get just 4 to 5 hours of sleep, Violanti added, while those on day shifts average about 6 hours. Training police officers of both genders on how to get a better night’s - or day’s - sleep would help them cope better with the stresses of their work, he said. Also, police departments need to make it more acceptable for officers who are experiencing mental health problems to get help.

SOURCE: American Journal of Industrial Medicine, October 2008.