London, Dec 23 : Hold your nerves. It's possible to wipe out bad memories and overcome depression.

Targeted medical intervention can help reduce specific negative memories in depressed patients, according to new research.

The technique, called electro-convulsive (ECT) or electro-shock therapy, induces seizures by passing current into the brain through electrode pads placed on the scalp.

Marijn Kroes, a neuroscientist at Radboud University Nijmegen in the Netherlands, discovered that by strategically timing ECT bursts, they could target and erase patients' memory of a disturbing phase in his or her life.

"This is what we call memory reconsolidation, where memories are taken out of 'mental storage' each time they are accessed and 're-written' over time back onto the brain's circuits," Kroes was quoted as saying.

To achieve this, 42 patients who had been prescribed ECT for severe clinical depression were showed two videos -- one depicting a car accident and the other a physical assault.

Afterwards, the patients received electro-convulsive therapy.

One day later, when given a multiple-choice memory test, patients were significantly worse at remembering details.

But when researchers administered the memory test 90 minutes after ECT treatment, patients showed no difference in their ability to recall the two stories.

"This suggests that the therapy blocked the time-dependent process of reconsolidation, rather than causing sudden memory loss," the researchers added.

"This also provides evidence that memories in the human brain undergo reconsolidation and that a window of opportunity exists to treat bad memories," added Daniela Schiller, a neuroscientist at Mount Sinai Hospital in New York.

However, the researchers said, more work is needed to know whether the technique works as effectively on older or more complex memories from real-life experiences.

"The ability to permanently alter these types of memories might lead to novel, better treatments," added Kroes.

The findings of the study have been published in the journal Nature.(IANS)