BACKGROUND: Depression is reported to be a major cause of illness-related 
sub-optimal work performance (presenteeism). However, the majority of studies 
examining presenteeism have relied on self-report measures of work performance. 
Furthermore, employers currently face a number of practical challenges in 
attempting to facilitate early identification of depression.
AIMS: To test whether a web-based screening tool for depression could be used 
successfully in the workplace and whether it was possible to detect an 
association between rates of depression and objective measures of impaired 
workgroup performance.
METHODS: All permanent employees of a telecommunications company with UK-based 
call centres were encouraged to complete a web-based psychological assessment 
using the Patient Health Questionnaire depression scale (PHQ-9). In addition to 
confidential individual level results, the tool was able to provide anonymized 
summary statistics for each workgroup. Four objective measures of work 
performance were collected for each workgroup.
RESULTS: During the study period, 1161 web-based PHQ-9 questionnaires were 
completed. There was a negative linear relationship between rates of depressive 
symptoms and the overall performance of a workgroup (P < 0.001). The linear 
relationship between depression and workgroup performance remained after 
controlling for gender balance, percent of temporary staff, employees' perceived 
level of engagement and satisfaction with their line manager (P < 0.01).
CONCLUSIONS: Workgroups with high levels of depressive symptoms tend to perform 
poorly. Computer-aided web-based screening for symptoms of depression is 
feasible in a work setting.