basket cases

“Basket case” has multiple meanings nowadays. Referring to a person it often means someone unable to cope with mental or emotional stress, especially due to anxiety. It can be temporary. Someone who is very nervous, tired, and unable to think or act normally. "By the end of the day, he was a complete basket case".

Used to describe a non-person, it can be anything that is impaired or incapable of functioning ot is beyond repair. For example, "The company was in such financial trouble, it was considered a basket case".

Simply defined, it means stressed out, or unable to cope

But why basket? 

WWI wounded arriving at triage station, Suippes, France

In World War I, soldiers who had lost all of their limbs and could not be safely carried on stretchers were put into makeshift baskets. The term is considered insulting and dates back to around 1919. 

The Oxford English Dictionary says the colloquial term “basket case” originated in the United States shortly after World War I, and meant “a person, esp. a soldier, who has lost all four limbs.”

But there is some evidence that is a mythic origin.

"However, the phrase, which initially referred to American soldiers supposedly left limbless by the war, was a product of the postwar rumor mill in the US. No quadruple-amputee American soldiers existed, and there’s no evidence that any head-and-torso survivors from any country were carried around in baskets."