“You have a biochemical imbalance in your brain. This medication will help correct that imbalance.” This is what most people diagnosed with a “mental disorder” will hear in the USA. Yet, there is no solid evidence of any such imbalance, no brain test, and most of the theories about particular imbalances have been actually disproven. Nevertheless, the mantra about imbalances is still chanted – because even though it is wrong and even though it robs people of hope of ever recoverying without drugs, it does help get people to “take their meds” and that is what our current mental health system is designed to do.
While there is no specific “chemical imbalance” that can be reliably found in people with a particular diagnosis, and no medication that restores a particular balance, there is lots of evidence that brain differences of various sorts play a role in mental problems. Does this mean that mental and emotional problems are sometimes “hard wired in” and full recovery is impossible? No, because modern science is showing how the brain itself is constantly being rewired, reorganizing itself, and this reorganization can lead to recovery. A very good and remarkably coherent summary of this reality is posted at http://bipolarblast.wordpress.com/2009/08/31/neuroplasticity-of-the-brain-2/