A new survey from anonymous business social network Blind asked its community of tech employees to answer "true" or "false" to the following statement: "I believe I am depressed" and 40 percent thought this was true.

Overall, 38.78 percent of the 10,081 tech workers who participated in the survey, which ran from November 20 to 28, said they believe they believe they are depressed. Amazon had the highest rate of employee depression (43.4 percent), followed by Microsoft (41.58 percent), Intel (38.86 percent), LinkedIn (38.73 percent), Facebook (36.7 percent), Uber (35.87 percent), Oracle (35.21 percent), Cisco (34.69 percent), and Google (33.11 percent). More than 30 percent of  Apple employees thought they were depressed, but that was because they were holding their emotions the wrong way.

"Users on Blind talk anonymously about burnout, high-stress levels, insomnia, overworking, and irregular work hours", Blind wrote. "These are all characteristics that have [been] shown to increase a person's chance of developing depression."

According to the World Health Organisation, depression is "characterised by persistent sadness and loss of interest in activities that you normally enjoy, accompanied by an inability to carry out daily activities for at least two weeks".