The Chelsea goalkeeper was at the centre of newspaper claims at the weekend that he had failed a drugs test.
Players' union leader Gordon Taylor believes Mark Bosnich has done the right thing by admitting himself to a depression unit.
Taylor, chief executive of the Professional Footballers' Association, said: "It's not always easy for an individual. Mark Bosnich has problems and has accepted that."
He told Sky Sports News: "It's up to everyone to understand that, and accept he's been big enough to admit himself into a clinic."
A statement released to the Press Association from the player's management company, SEM, read: "Mark Bosnich has been diagnosed as suffering from severe clinical depression.
"On medical advice he was today admitted to a depression unit of a medical facility to obtain treatment for that depression.
"It would not usually be appropriate to release this type of information, which is private in nature, but it has been decided to do so on this occasion to prevent speculation.
"Mark thanks the press for their support at this difficult time and asks in the circumstances that further information as to his treatment and whereabouts should remain private."
Chelsea Mad would like point out that since this is the first official statement that has been released with regard to the recent “allegations/stories”, we feel it only appropriate to report this matter, at this point. Chelsea Mad will not “speculate” or report on such a personal, serious issue until we are party to all the facts.
Considering today’s press statement, Chelsea Mad would like to send their best wishes to Mark.