A medicine you take when you have diabetes and breast cancer and not when you have adhd and you have been taking then and then you stop you turn into Muslim terrorist

A phrase to describe someone who is cognitively degenerating. Synonym of "going off the deep end". Can have varying degrees of severity.

Reference to the song "Hey You" by Pink Floyd. The line "and the worms ate into his brain" makes no sense in an otherwise linear and literal narration throughout the lyrics.