MEASURING stress hormones could reveal which patients are likely to suffer
longer-lasting side effects after electroconvulsive therapy, say doctors in
California.
Shock therapy is still widely used to treat depression in the US, Canada and
Britain. Many people associate it with the infamous scene in One Flew Over
the Cuckoo鈥檚 Nest in which Jack Nicholson鈥檚 character, strapped to a table,
convulses in pain during shock treatment, and some ex-patients and doctors are
strongly opposed to its use.
Nowadays, however, patients are always given anaesthetics and muscle
relaxants to prevent pain and the violent convulsions that can cause injuries.
Most psychiatrists agree that the evidence shows that electroconvulsive therapy
(ECT) is safe and can help patients with certain forms of severe depression, at
least in the short term. It is also usually tried only when other treatments
fail, and patients are asked for consent in the vast majority of cases.
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Nevertheless, the treatment has unpleasant side effects. All patients have
memory blackouts for events close to the time of the treatments. For a while,
their ability to learn new things, like phone numbers, is impaired. 鈥淢ost
people, if not all, will have short-term cognitive side effects,鈥� says
psychiatrist Thomas Neylan of the University of California, San Francisco.
鈥淭hey鈥檙e more forgetful, less sharp.鈥�
In some people these effects can last much longer, up to a few months. This
can have serious consequences, Neylan says. But his team has now found that
levels of the stress hormone cortisol might indicate which patients will suffer
most from these side effects.
The team looked at 16 patients who had consented to ECT as a treatment for
major depression. The patients gave saliva samples before starting their course
of ECT, and took several tests to assess their mood, cognitive functioning and
memory on the day before ECT, and on the day after their sixth treatment.
As expected, the patients experienced a significant improvement in mood and
depressive symptoms after the treatments and also suffered from a decline in
memory and cognitive function. But Neylan found that the higher the base level
of cortisol for each patient, the higher the cognitive impairment after ECT. His
findings have been submitted to the journal Biological Psychiatry.
According to Bruce McEwen of Rockefeller University, the next step is to find
out more about the daily pattern of cortisol after the ECT. 鈥淭he prediction is
that it would be elevated more in those subjects with the pre-ECT elevation of
cortisol,鈥� he says.
The results are preliminary, because the study was so small, Neylan warns.
But if they are confirmed by further studies, measuring cortisol in patients
before ECT may become a way for doctors to pinpoint those people who are at risk
of memory loss.