Concerns have been raised that people are becoming “numb” to mental health incidents on the Tay Road Bridge.
The claim follows an incident on the bridge in the early hours of Sunday.
Charlotte Liddell was a passenger on a bus heading to Fife after enjoying an evening out in Dundee city centre.
The service came to a stop at the bridge which had been closed to traffic.
It is understood a man was in distress after leaving the pedestrian walkway.
The bridge was closed for about 45 minutes as emergency services tried to talk the man down.
Charlotte said that while emergency crews dealt with the situation, other passengers were speaking negatively about the man because he was delaying their journey home.
The 22-year-old said she was disgusted when passengers cheered after the bridge reopened.
Charlotte is a volunteer with Fife lone parent and family charity Gingerbread.
She said until her troubling bus journey, she had not encountered people who spoke so disparagingly about those with serious mental health difficulties.
She said: “Sitting on that bus I felt absolutely helpless – it was horrific.
“I couldn’t stop thinking of the person on the bridge.
“Even though the person on the bridge may never know what people on the bus were saying, I knew.
“It’s sad to see that it happens so often that people have become used to it, numb to it.
“It’s not an individual with unspeakable pain.”
She added: “People had the nerve to cheer when the bridge reopened – not because the person was taken to safety but because they could get home.
“I’ve never had an encounter before with people who don’t understand.
“I thought it was just common sense to show empathy in situations like that.”
Police Scotland confirmed the incident was resolved safely.