William Saffire's NYTimes piece, The Risk that Failed, highlights the growing interest and importance of neuroethics:

"the field of philosophy that discusses the rights and wrongs of the treatment of, or enhancement of, the human brain."

"Not just neurosurgeons but other brain scientists are thinking long and hard about the morality (right or wrong) and the ethics (fair or unfair) of what such breakthroughs as genomics, molecular imaging and pharmaceuticals will make it possible for them to do.

In the treatment or cure of brain disease or disability, the public tends to support neuroscience's needs for closely controlled and informed experimentation. But in the enhancement of the brain's ability to learn or remember, or to be cheerful at home or attentive in school, many of the scientists are not so quick to embrace mood-manipulating drugs or a mindless race to enhance the mind."

Throughout our evolutionary history, emotions, like fear or anger, have been easily able to bump rational thoughts out of our awareness.  Non-emotional events, like a thought, have not easily been able to displace emotions from the mental spotlight—wishing that anxiety, pain or depression would go away usually doesn’t work.  While conscious control over emotions is weak, emotions can flood consciousness.

Advancing neurotechnology has the potential to change this evolutionary fact. For the first time, neuroceuticals could allow our cognitive “thinking” self to a higher degree of control over our “emotional” self than ever before. 

Human emotions have been honed over millions of years by natural selection to be trigger-happy. Emotions like anger, anxiety and fear were highly selected for in our ancestors because they helped them survive in the harsh open savannahs of Africa.  However, in today's society many negative emotions no longer provide the selective value they once did.  Instead many emotions actually get in the way of cooperative efforts to solve problems.  Perhaps reducing some of our emotional responses and tendencies might help humanity organize more effectively and peacefully.

Clearly emotions like anger, anxiety and depression are useful evolutionarily mechanisms that alert us to the fact that something might be wrong and help us coordinate our responses. As appealing as it might sound to wipe out negative emotions, it would be as harmful as taking away someone’s ability to feel physical pain.  Without the physical feeling of pain we would walk across hot coals, burning our feet beyond recognition, without ever knowing it. However, as valuable as our ability to sense and react to physical pain is, there is no reason that a person in physical pain should not take an aspirin or a painkiller to modulate their pain.  Should the same follow suit with mental pain?

In other words, how much of a “bad” thing is good?  This is a critical question that neuroethicists will need to grapple with in the years to come.