Two hundred and fifty years ago, a Scottish doctor named William Cullen noticed something strange. If he gave patients a bread pill or saline solution, with the same care and conviction as if he believed he was giving them an effective treatment, a patient’s condition often improved.
We now call such a response to an inert treatment the ‘placebo response’.
In Cullen’s case, we cannot know what was causing the patients to get better. We tend to seek treatment when we are at a low point, and most illnesses get better over time without intervention, so was the doctor mistakenly attributing the improvement to the treatment, when in fact it was just the natural expected recovery? Was the doctor or the patient biased by the knowledge that a ‘treatment’ had been given which led them to look for evidence of improvement, or to report improvement? Did the patient feel obliged to report they felt better to satisfy the doctor who was apparently trying his best to treat them? Or was there some direct psychological effect resulting from faith in treatment that led to improvement?
After World War II modern clinical trial methods were developed with the aim of finding specific biologically active treatments whose effects could be distinguished from these non-specific placebo responses.
In a typical, modern, placebo-controlled clinical trial, a ‘placebo group’ receives an inert medication or treatment instead of the active treatment given to the ‘test group’, but is otherwise treated identically to the test group. It is the whole therapeutic context - not just any inert medication - that forms the placebo condition. The outcome of the two groups is then compared, and the difference in outcomes between the two groups is the effect attributed to the active treatment.
If we subtract the outcome of the ‘placebo group’ from that of the ‘test group’, we should remove any apparent improvement that results from natural recovery from an illness, bias, trying to please an experimenter, and expectation of improvement, for example, as these effects should be the same in both groups.
It turns out that for treatments aimed at alleviating psychological diseases, such as depression, anxiety or chronic pain, placebos are as effective or almost as effective, as many conventional ‘real’ medications. Or in other words, well-established drugs that are prescribed with an apparently sound scientific rationale, are often no more effective than the modern equivalent of a bread pill delivered with care and intent.
How can this be? On the face of it, this finding appears to violate widely held views about medical treatments.
Notice that this does not mean that placebo treatment or drugs have no effect: it's just that whatever effect(s) they have, it is often of a similar size. Further studies suggest that the natural progression of a disease, reporting bias or trying to please, can account for a substantial proportion of the apparent improvement observed in both placebo and test groups. And in the test group, we might hypothesize that some effects might be accounted for by the biological action of the drug.
But the most interesting and surprising finding for us here is that the expectation of receiving an active treatment can itself directly activate processes that improve outcomes. This 'psychological healing' component of the overall response seen in a 'placebo group' (that additionally includes the effects driven by the natural regression of an illness, bias, perceived demands) is sometimes called the 'placebo effect'.
In a further twist, the placebo effect component is not limited to the placebo group. A belief about treatment is central to at least some of our treatment responses to drugs too. Irvine Kirsch, Professor of Psychology and lecturer in medicine at the Harvard Medical school, has argued that psychoactive drugs that perform better than a given placebo control group, may merely be ‘super-placebos’ - that is, particularly effective placebos. He suggests that the side effects associated with a real active drug increase a patient’s belief that they have in fact been given the active drug, thereby increasing the expectation of a positive effect - leading to an increased placebo effect. In accord with this, if inert placebo medications are given with substances that mimic the side effects of active drugs, the outcomes for the (placebo) medication is increased.
Unsurprisingly, these views are considered explosive by some. However, there is a growing acceptance that the biomedical model of mental illness and treatment does not adequately explain placebo or drug treatment effects.
We now know that there are in fact multiple ‘placebo effects’ that depend on different psychological, biological and social responses to aspects of the treatment context. The precise mechanisms activated depend on how well belief, expectation, conditioning, memory activation, somatic focusing, anxiety reduction and so on are activated by a therapeutic context, which varies from individual to individual.
It is easy to see how new beliefs (‘I am getting an active treatment’ ‘these people can help me’, ‘I can change’), hope and expectation (‘I will get better’) and conditioning (in the past medication has worked, so we are biologically primed to respond positively to it), and stress relief could affect how we feel. In general, a warm, caring treatment context and a plausible rationale for treatment lead to better outcomes, irrespective of other treatment factors.
Some researchers have suggested that whilst placebos may make us feel better subjectively, they do not, in fact, make us any better objectively. Leaving aside how much sense this objection makes when we are thinking about mental health, it is in fact increasingly clear that ‘placebo healing’ can activate the very same pathways that are implicated in accepted biochemical explanations of drug effects. Neurobiologically, placebo effects are correlated with wide-ranging biochemical changes in opioid and non-opioid signaling, in neurotransmitter and neuromodulators and neural metabolism; as are drug effects.
In Cullen's time as now, the idea of a ‘placebo treatment’ smacks of deception and placation, and modern medicine has generally treated placebo responses as something to be managed in order to develop 'better drugs'. However, placebo research is beginning to offer new ideas about what might really be important in treating mental illness.
What Does This Mean For Me?
Firstly, do not stop taking any medication you are already taking without first seeking professional help to discuss whether this makes sense for you at this time. Drugs have very real effects on our brain, and stopping them without care can sometimes cause severe difficulties. Psychologically-mediated placebo effects and drug effects may sometimes have a similar effect size, but that does not mean that drugs 'don't do anything' - they may have direct physiological and indirect psychological effects. For a given person at a particular point in time, medication may well be the best way to support mental health; and some people may always find medication to be necessary.
Having said that, exploring other avenues for improving your life and mental health is a good idea, even whilst taking medication. It is always worth making time for appropriate exercise, a good diet, adequate sleep and stress reduction, all of which are known to have a genuinely positive effect on brain function and mental health.
It’s also worth considering psychotherapy either alone or in association with medication. Research comparing placebo interventions to talking therapies suggest a similar short-term picture to that for drugs - that is, psychotherapy leads to outcomes that are similar or a little better than placebo treatments. However, crucially, in the long-term, talking therapies lead to more sustained remission, fewer relapses, and of course fewer physical side effects than psychoactive drugs.
Secondly, be very skeptical of unsubstantiated claims and personal anecdotes about treatments such as those in advertisements and social media. Broadly speaking, if someone believes a treatment might work, it may well make them feel better - though it may be no better for them than something else they believe in.
‘Feeling better’ is, of course, a positive outcome, when the aim is to improve how we feel, and appropriate alternative treatments can sometimes improve our quality of life and reduce stress. In fact, this is a major benefit of alternative therapies. Feeling in control, understood, listened to and cared for (all of which enhance the placebo effect) is sometimes easier to find with a paid-for alternative therapist than in a busy mainstream medical practice. And placebo effects can genuinely kick-start recovery and healing. However, we should be wary of feeling compelled to spend money we don’t have on treatments we don’t need.
Much more problematically, if we take something biochemically inert and feel better - for medical conditions that cannot be treated by placebos such as cancers, blood clots or infection - we put ourselves in serious danger if we believe ‘feeling better’ means that the underlying problem is improving and we delay seeking active treatments. Unfortunately, there are many charlatans trying to take advantage of our wish to be well and offering improbable snake-oil treatments for life-threatening conditions.
Many of us have some rituals of self-care that may include exercise, a good diet, sleep, positive social life or stress management. All of these activities are inherently positive in their own right and are also likely to trigger placebo effects to varying extents. We can enhance aspects of the placebo healing effect further, by bringing attention and awareness to the ways we look after ourselves and help ourselves, and focusing on what we need and how we can provide that. For some of us, focused meditation or prayer can be important for directing our attention and focus.
Placebo research also suggests that really understanding why self-care makes a difference to our mental health (e.g. how does exercise actually help? or why breathing exercises relieve stress) would further enhance the already positive effects of these activities on our health through increasing our expectation and 'buy-in'.
