Keep but rewrite. chemically imbalanced is a fairly popular euphemism for mad or mentally ill, and there are some cites for chemical imbalance as a direct euphemism for madness. "An imbalance of chemicals" is SOP, "a mental illness" is not.
2009, Warden, Rob and Drizin, Steven, True Stories of False Confessions, ISBN 0810126036, page 28:
Anyone who knew him well would suspect he had a chemical imbalance. He had been unhappy recently. And there was a history of suicide in the family; his mother had tried to kill herself.
If this is kept, the context tag should be removed as use is not restricted to a medical context, as the citations show. There is probably a class of euphemisms that are derived from what ordinary folk view as social-science and medical excuses for bad behavior, along the lines of "He's depraved on accounta he's deprived" (West Side Story). DCDuringTALK 12:30, 3 April 2012 (UTC)
I'd imagine any imbalance of a chemical nature could be called a chemical imbalance, but I can see why someone would create this. I'll sit on the fence, for now, anyway. Mglovesfun (talk) 12:36, 3 April 2012 (UTC)
Funnily enough, in a psych textbook at some point I remember reading about a policewoman with trichotillomania whose comrades on the force knew she that she wore a wig, but whom she'd told that her baldness was due to a "chemical imbalance". She clearly felt that "chemical imbalance" did not imply "mental disorder", or else she would not have chosen that cover story! —RuakhTALK 13:44, 3 April 2012 (UTC)
Keep but rewrite per Smurrayinchester. His quotations suggest a euphemism. Ungoliant MMDCCLXIV 15:08, 3 April 2012 (UTC)
OK, I've removed the RFD tag, added an &lit as a first step towards accounting for the existence of literal and other senses (like the one Ruakh's policewoman used), and rewritten the other definition. - -sche(discuss) 17:54, 3 April 2012 (UTC)
Appears resolved. Striking.DAVilla 02:15, 8 April 2012 (UTC)