Origin of 'Nerverein'

[tigger4537]

Hallo allerseits!

I've been listening to Udo Lindenburg's 'Mädchen aus Ost berlin' and came across 'sonst gibt's die größten nerverein' which, from the context, implies 'trouble' but I can't find this word in any dictionary. Is it slang German and where does it come from?

Many thanks

Richard