Do antidepressants cause emotional numbing?

George Dawson (mentioned eg. in a previous post) and Ronald Pies (also mentioned eg. in another previous post) argue in a Psychiatric Times article that antidepressants do not work by numbing emotions. They wrote the article to counter the claim by Joanna Moncrieff and Mark Horowitz, members of the Critical Psychiatry Network (CPN), that one of the pharmacological actions of antidepressants is emotional numbness and that is how they “work”. This hypothesis builds on Jo’s differentiation of a disease-centred and drug-centred understanding of the mechanism of drug action (see previous post). Psychiatric drugs do not necessarily work because they are correcting a disease process (disease-centred model) but because they have drug effects that may be useful in managing the illness (drug-centred model). Emotional numbing is hypothesised to be of benefit when using antidepressants for depression. 

Also being a member of CPN, I have some concerns about Jo and Mark’s claim. I accept that emotional numbing is a common side effect of antidepressants, particularly in long-term use. I don’t think it’s usually a very immediate consequence of taking antidepressants, for example within the short-term (often about 6 weeks) clinical trials that are used to make claims about the effectiveness of antidepressants. So, I don't quite see how emotional numbing can explain any significant difference between antidepressant and placebo demonstrated in these trials over the short-term. 

But over the longer-term, people often complain that antidepressants seem to have stopped them really dealing with their problems and complain of a flattening of emotional responses which includes feelings of being ‘dulled’, ‘numbed’, ‘flattened’ or completely ‘blocked’, as well as descriptions of feeling ‘blank’ and ‘flat’, affecting their relationships with others and how they see themselves (see previous post). If antidepressants have seemed to help, even if more because of a placebo effect than true antidepressant action, then it's not surprising that people may feel that a physical rather than psychosocial approach to their depression has not really helped. They may express that as emotional numbness and not being in touch with their feelings. They might even still have the same underlying personal and social reasons that led to their depression, which haven't really been dealt with, as such, by mere taking of an antidepressant.

The trouble is that there is only a limited literature about emotional numbing caused by antidepressants that does not allow proper assessment of its significance and mechanism. One study that is commonly quoted is Goodwin at al (2017). They found that emotional blunting is reported by about half of people on antidepressants and is correlated with their depression score ie. a poorer quality of remission is associated with more blunting. However, the screening method used a leading question ‘To what extent have you been experien­cing emotional effects of your antidepressant?’, and followed this up with an explanation that ‘emotional effects vary, but may include, for example, feeling emotionally "numbed" or "blunted" in some way; lacking positive emotions or negative emotions; feeling detached from the world around you; or "just not caring" about things that you used to care about’. Those that gave a positive response were asked to complete a fuller questionnaire about emotional blunting. 

As the paper admits, the data is very much affected by subjective factors. People were guided by the methods used in the study into essentially having a wide understanding of the meaning of emotional numbness or blunting. I tend to think what's meant by emotional numbing is more to do with people feeling antidepressants are masking the real problem and thereby preventing them having their full range of experiences, rather than a direct physiological effect of the drug. Jo and Mark disagree with me about this, but I'm not convinced they've got the evidence for their view. People commonly, at least initially and maybe over time if they can sustain having stopped the antidepressant despite withdrawal symptoms, say that they feel more alive and in touch with their feelings after stopping the drug. That may not be surprising, as there must be relief, at least, that they do not have to take the antidepressant. There must also be a sense that emotions are no longer being controlled by the antidepressant. Trouble is that it's not always very easy stopping antidepressants, perhaps particularly if they were started when there didn't seem to be much alternative and the person has been misled into thinking that there must have been something wrong with their brain. This means that they get stuck in a vicious cycle of wanting to stop antidepressants but fear relapse and withdrawal symptoms if they've previously experienced them. Withdrawal symptoms are very common (see eg. previous post).

It worries me how the notion that antidepressants work by emotional numbing seems to be catching on, perhaps particularly with patients. As I've said, I'm not convinced there's the evidence for the hypothesis. As I've commonly said, I tend to think antidepressants are no better than placebo (see eg. previous post). That doesn't mean that I think they're inert. In fact, the reason I think antidepressants are no better than placebo is because I think the significant difference between antidepressant and placebo found in short term trials may be a methodological artefact. This arises, for example, because trials are not as double-blind as is commonly assumed. Trial participants may well be able to break the blind in randomised controlled trials because of side effects, so I'm not saying antidepressants are inert.

But I do worry that critics of biomedical psychiatry may be creating another myth, like the serotonin hypothesis, that antidepressants work by emotional numbing. In fact, because I don't think antidepressants probably work any better than placebo, in a way I'm saying they don't "work". There's no need, therefore, to even have an explanation of how they "work"! That's not meant to undermine the people that feel that antidepressants have helped (see eg. another previous post) but the limitations of medication do need to be acknowledged. The trouble is that mainstream psychiatry is committed to supporting the use of antidepressants because they are seen as effective.