by Duncan Double
Openmind 158, July/ August 2009
A recent commentary on deep brain stimulation (DBS) discussed its potential as treatment for psychiatric disorders [1]. Despite this ‘sense of great expectancy’, it also recognized the importance of proceeding ‘with a combination of humility and hubris’. The lessons from past errors of psychosurgery, when large numbers of brain operations were performed based on very little clinical evidence, reinforce the need to recognise the placebo effect in psychiatric disorders. Apparent effects may be dependent more on fulfilling our wishes than reality. DBS is also not without risks, including intracranial bleeding, infection and behavioural effects induced by the electrical stimulation.
DBS involves placing one or two thin wires into specific locations deep within the brain and then connecting the wires to a battery situated just beneath the skin. The technique has been used for treatment–resistant movement disorders such as Parkinson’s disease. There are reports of its use in depression and obsessive-compulsive disorder, but no published clinical trial data.
Frontal lobotomy was introduced in the 1930s to separate the frontal lobes from the rest of the brain. The intention was to reduce disabling fear, taking the ‘sting’ out of mental disorder. Walter Freeman, an American psychiatrist, developed the operation by accessing the frontal lobes through the eye socket with an icepick. He regarded this as a minor procedure and could operate several times a day, sometimes in public.
Psychosurgery is still performed on selected patients, making fairly focal lesions guided by brain imaging. Unlike these brain lesioning techniques, DBS is reversible. The authors of the commentary argue that patients should be assessed by an interdisciplinary professional panel and followed up, ideally enrolled in a clinical trial, and the procedure only used when all other interventions have failed.
They also say that DBS should only be used ‘when there is a high likelihood that the lives of patients will be improved by its use’. The trouble is that there is uncertainty as to whether this will be the case. Psychiatry has always been motivated by enthusiasm for interventions in desperate situations. It has also tended to reduce people to ‘abnormal’ brains. We may all want a simple, quick, cheap, painless and complete cure. Even though we may realise this is not always possible, surely psychiatric services can offer more hope and effective interventions for people than DBS.
1. Kringelbach, M.L. and Aziz, T.Z. (2009) ‘Deep brain stimulation: Avoiding the errors of psychosurgery’, JAMA 301: 1705–7.