Synonyms for Unbalance (same or very similar meaning)
WordNet sense 1 (a state of mental disturbance and disorientation):
derangement, mental unsoundnessWordNet sense 2 (a lack of balance or state of disequilibrium):
imbalance, instabilityWordNet sense 3 (derange mentally, throw out of mental balance; make insane):
derangeFrom the ODE community, based on WordNetadd/edit