I love this. It's a massive poster in a tunnel at Euston and every time I walk past it during the commute home it makes me grin.
In related deliciously dark humour news, my manager now prefaces even minor criticism with "don't kill yourself, but..."
Not that I'm recommending this as a general policy for Handling Your Local Mental, but it's exactly the way I personally like people to deal with it. I might be losing my ever-tenuous grip on sanity, but you don't have to treat me like a bomb that could explode at any moment. Serious Voice and Sad Face will not fix the Broken Brain. Laughter may not be the best medicine - in my case, 40mg of citalopram per day is the best medicine - but taking the piss out out of mental illness (as distinct from taking the piss out of people with mental illnesses) is a lot less depressing than turning it into some all-powerful godbeast. It's not bloody Darth Vader.