People recently prescribed an antidepressant are more likely to commit suicide than those given a prescription more than 30 days earlier, researchers have discovered.
A new Boston study found that the newer style of antidepressants the serotonin reuptake inhibitors were no safer than their earlier counterparts, the tricyclics. Fluoxetine (Prozac) was the only one of the new breed linked to higher suicide levels, although researchers at the Boston University Medical Center say that figures may have been skewed.
Psychiatrists and doctors have favoured inhibitors because they were considered safer if there was an overdose, but the Boston study showed suicide rates were similar across both types of antidepressants. Overdose accounted for just 14 per cent of suicides.
The problem may be that serotonin is a chemical in the central nervous system which suppresses harmful behavioural impulses. It is thought that people become suicidal, aggressive or violent when it is lowered, as has been seen with cholesterol-lowering drugs. The inhibitors are also found in some new migraine drugs and treatments for pre-menstrual tension (PMS).
The safest antidepressants, the Boston team discovered, were maprotiline and desipramine, as they had no suicides connected to their use, although researchers warn that their usage was far lower than the other drugs monitored and so may not have been representative.