Star Trek: The Next Generation – Dark Page [7.7]

During a diplomatic mission on the Enterprise, Lwaxana Troi behaves erratically and eventually collapses when her own telepathy turns in on herself.  With the help of another telepathic species, Deanna is able to visit her mother’s nightmares, and eventually discover that she is repressing a terrible trauma from her years ago

Star Trek: The Next Generation – The Loss [4.10]

Troi suddenly loses her empathic sense as the Enterprise finds itself being towed to its potential destruction by a swarm of two dimensional beings.