Nervous breakdown

From Memory Alpha, the free Star Trek reference.

A nervous breakdown was a term used to describe a sudden attack of mental illness such as depression or anxiety.

In 2270, the USS Enterprise's entry into an unidentified energy field placed subatomic particles into their ship's main computer. Once the crew members began to experience practical jokes, Spock identified what the computer was experiencing was the electronic equivalent of a "nervous breakdown." (TAS: "The Practical Joker")