Deep brain stimulation involves the implantation of electrodes within the brain which are connected with wires to a electronic impulse generator implanted in the chest. This "brain pacemaker" then emits a current which stimulates a specific area of the brain, in this case a location called the habenula.

The habenula, according to the report, is a location next to the brain stem responsible for control of three major neurotransmitter systems which are believed to be involved in depression.

The researchers received accidental confirmation of the operation's success when the device was switched off during preparation for a unrelated surgical procedure and then no one remembered to turn it back on for several days. The patient's depression immediately returned, but then abated once the brain stimulation was resumed.

Another larger study is planned with hopes that it will prove that stimulation of the habenula is both safe and more effective than stimulation of other brain locations in relieving treatment resistant depression. If it proves effective, this could be wonderful news for those who have struggled to find a treatment that helps them.