The psychologist is a co-worker. The woman becomes ill, has an emergency hysterectomy and no longer can have children. Her husband is leaving her due to no more children. Psychologist approaches boss and tells boss that woman is suicidal and not fit to come to work. The boss does not allow woman to return to work until psychologist feels she is fit to return.
If the information did not come about because of a patient-doctor relationship, then there is no confidentiality. However:
What business does the doctor have telling the employer? If he's a doctor (co-worker) doing doctor work for her employer, then it would be odd if he wasn't in some way her doctor, and therefore obliged to treat her information with confidence.
If he was in some way her doctor, then he would be combining what he knew from doctor visits with what he know from the bar, and so spilling some part of confidential information.
If he had not treated her, but just had a bar conversation once upon a time with her, how qualified is he to judge her mental state, to the point where he would have her suspended/fired?
OTOH, if you're sitting in a bar with someone, doctor or not, and they confess to you "sometimes I just feel like driving the loaded bus off the high point of the bridge, I'm so depressed", I would think you have an obligation to tell someone.
"...until the psychologist feels she is fit to return to work."??? Now suddenly he IS her doctor until she's better? Having stuck his nose into the case and being an employee of one party and snitched on the other, he's hardly qualified to give an impartial judgement of her condition later.
Besides, what happened to the Hippocratic oath of "...first, do no harm..." if he's getting her suspended?
I would say MYOB is the first rule of a professional involved in a non-professional social situation. Unless she was a real danger to others (and explicitly said so) it's not up to the psychologist to butt in.
OTOH, if someone said something that threatened the life or livelihood of others around her, ANYONE has an obligation to snitch unless there is a specific confidentiality in force.
If they simply threaten suicide themselves, you shouldn't tell anyone (except, say, her doctor who is obliged to keep it confidential) without their permission. telling the whole world will just make matters worse.