Indoor air quality may influence the health of inhabitants. Few studies have examined the role of air pollution in the etiology of depressive disorder. The purpose of this study is to further explore the relationship between the indoor air quality and depressive disorders. The mean CO2 concentration, relative humidity and temperature were 1414 ppm, 49.1%, 24.3 °C in indoor air, respectively. The complaints of sick building syndrome were reported in 75.4% of the participants. 32.1% of the participants who filled in the Beck Depression inventory (BDI) questionnaire form (n = 196) reported minor depressive symptoms, 8.7% of them reported moderate depressive symptoms and 5.8% of them reported severe depressive symptoms. Moderate positive correlation was found between the carbon dioxide levels and the depressive symptoms reported in the BDI, in addition a weak positive correlation between the reported poor quality of life and sick building syndrome complaints. These results indicate that the physical and mental health of the inhabitants of buildings with poor indoor air quality seems to be adversely affected as evidenced by increased depressive symptoms and reported poor quality of life.