
Police arrived at the bridge at about 9.40pm after Pithak Daengprasert, 35, was seen standing on the bridge beside his motorcycle.
Pithak had climbed over the guardrail and stood on the edge of the bridge, clinging to the rail.
While police tried to convince him to climb back, he plunged to his death.
Police said Pithak had regularly received drug treatment at Srithanya Hospital and had recently been admitted to a drug addict rehabilitation centre.