Recent articles in the psychiatry literature http://www.physique.com/news199986110.html has reached the public at large demonstrating that iv ketamine can significantly improve the depressive symptoms of manic-depressive patients resistant to other treatment.
The significance of such research, I believe, is the demonstration that we live in an emotional bath of neurochemical transmitters. Our emotional equilibrium is directly connected to brain chemistry. We naively believe that we have control over our feelings/emotions. In many ways we do not.
It is clear that personal events, thoughts, worries can lead to feelings of sadness and that we can often "think" our way out of these states by utilizing techniques of meditation and cognitive/behavior therapy (CBT).
But for those unfortunate enough to suffer from major depressions and/or manic-depression, more radical efforts are necessary.
Talk therapy, even self-talk will not due.
The patient is suffering from a powerful disturbance in an otherwise self-regulating neurochemical state of being. Standard pharmacological approaches have failed. The potential for self-injury or even suicide is great.
The treatment much be aggressive and directed towards altering disturbed neurochemical processes. The powerful anesthetic ketamine seems to offer hope.
Let us hope that this observation will encourage even more research into the underlying neurochemical origin of emotions and potential life-saving treatments.