Why antidepressants can blunt both negative and positive emotions

Escitalopram, a generally prescribed antidepressant, lowered individuals’s sensitivity to rewarding experiences in a small trial

By Clare Wilson

An undesirable flattening of all feelings is without doubt one of the most frequent uncomfortable side effects of antidepressants – and now we all know extra about why it may occur.

The mostly used forms of antidepressant belong to a category known as selective serotonin reuptake inhibitors (SSRIs). These are thought to work by rising ranges of the mind chemical serotonin, though why this could enhance our temper is unclear.

Up to half of individuals taking antidepressants expertise an undesirable dampening of each optimistic and damaging feelings. “They talk about not feeling much,” says Barbara Sahakian on the University of Cambridge.

Depression itself additionally typically causes a scarcity of delight in actions an individual as soon as loved. Sahakian and her colleagues due to this fact investigated an SSRI’s emotion-dampening impact in individuals with out the psychological well being situation.

The researchers gave both a generally prescribed SSRI known as escitalopram or placebo drugs to 66 individuals with out depression. After three weeks, the contributors carried out a variety of duties involving reminiscence and studying.

One process measured how effectively they realized from rewards, with individuals having to repeatedly select between two stimuli. Through trial and error, they typically realized that one stimulus led to a reward extra typically than the opposite. Then the possibilities of a reward for every stimulus would swap and the contributors needed to be taught this new system.

The contributors who took the antidepressant have been 23 per cent much less delicate to the stimuli swap than these taking the placebo, as measured by how shortly they modified their stimulus choices. Other checks confirmed that the drugs didn’t scale back their cognitive skills in different methods.

The discovering means that SSRIs scale back individuals’s sensitivity to rewards or different pleasurable experiences, says Sahakian. But the medicines also can blunt the depth of damaging emotions, which will be useful, she provides.

“I hope this doesn’t make doctors more cautious about prescribing antidepressants as they’re extremely important drugs,” she says. “I hope it would make doctors have a discussion with patients about potential side effects.”

“Why antidepressants cause emotional blunting in a subset of people is a really important question,” says Catherine Harmer on the University of Oxford. “I don’t think this result explains why people have this effect, but it may be a marker of it, which could be useful when we come to develop new treatments that don’t have it.”

Harmer says the research would have been extra helpful if the contributors had additionally been requested in the event that they skilled blunted feelings whereas taking the antidepressant.