Humans can have bad or good memories. Good memories give us happiness whereas bad memories can torture sometime. Recent study has shown that a drug, used for treating for high blood pressure can be used to remove bad memories.

Animal studies have already shown that fear memories can be altered at the time they are recalled because at this crucial stage the memories are "reconsolidated" in the brain. In the recent study, Dutch researchers created a fearful memory in 60 study subjects using artificial means. Fearful memory was created by associating pictures of spiders with a mild electric shock delivered to the wrists of the study subjects. After 24 hours, when study subjects were shown spider pictures, they give "startle" response - a measure of fear. When they were given the beta-blocker drug propranolol, there was a marked reduction in the startle response. The spider fear seems to vanish permanently from mind of study subjects.

Lead researcher, Professor Merel Kindt and colleagues from the University of Amsterdam said: "Our findings may have important implications for the understanding and treatment of persistent and self-perpetuating memories in individuals suffering from emotional disorders."

Dr Daniel Sokol, a lecturer in medical ethics at St George's, University of London, added: "Removing bad memories is not like removing a wart. It will change our personal identity since who we are linked to our memories. We must reflect on the knock-on effects that this will have on individuals, society and our sense of humanity."