Personal ViewOvert versus covert treatment for pain, anxiety, and Parkinson's disease
Section snippets
Informed consent
Informed consent is an important issue in open versus hidden treatment methods. Different approaches are used to obtain full, informed consent and there is no general rule. Most study participants are told that they could receive either an active drug, a placebo, or nothing, thus giving their informed consent to receive different treatments. When drag administration is hidden, participants believe that nothing is being given. For example, postoperative patients are told that they could receive
Open versus hidden injections of analgesic and antianxiety drugs
In the 1980s and 1990s, some studies were done in which analgesic drugs were delivered by machines through hidden infusions.8, 9, 10, 11 Infusion of a drug can be hidden by use of a computer-controlled infusion pump that is preprogrammed to deliver the drug at the desired time. Importantly, the patient does not know that any drug is being injected. This hidden procedure is done easily in the postoperative phase; the computer-controlled infusion pump delivers the painkiller automatically,
Open versus hidden deep brain stimulation in Parkinson's disease
We have applied the open—hidden method of study to the treatment of Parkinson's disease, specifically deep brain stimulation (DBS) of the subthalamic nucleus (STN). Two types of evidence suggest that hidden DBS is less effective than open treatment: study of stimulation with macroelectrodes in the postoperative phase13, 14 and study of autonomic and emotional responses to intraoperative stimulation with microelectrodes (figure 4).15
Firstly, we studied ten patients with idiopathic Parkinson's
Clinical implications
Although the evidence for differential effects of open and hidden treatments is limited to disorders involving the nervous system, and thus is not generalisable to all medical and surgical treatments, these provocative studies have two major findings. First, although many factors and variables may contribute to the differences between the outcomes of covert and overt treatments, certainly the awareness of the treatment, the presence of the therapist, and the expectation of the outcome are
Ethical considerations for clinical trials
The ethics of the open-hidden methods is relevant beyond routine medical practice and involves many parts of biomedical research. The use of placebos in clinical trials is still the focus of a hot debate and lively discussion. Critics of placebo-controlled trials have condemned the use of placebos because withholding proven, effective treatment results in suboptimum treatment. In other words, placebo groups do not receive the best treatment available. The World Medical Association (WMA)
Conclusions
We believe that the open-hidden approach can be used to address many unanswered questions, including nature of the placebo effect. When we measure the difference between open and hidden treatments, the term placebo effect is misleading because no placebo has been given. Therefore, the difference could be better described as the psychosocial component of treatment that comes from patient knowledge that they are receiving treatment. Our research shows that administration of drugs or brain
References (40)
- et al.
Response variability to analgesics: a role for non-specific activation of endogenous opioids
Pain
(2001) Assessing placebo effects without placebo groups: an untapped possibility?
Pain
(2001)- et al.
Analgesic responses to morphine and placebo in individuals with postoperative pain
Pain
(1981) - et al.
Potentiation of placebo analgesia by proglumide
Lancet
(1995) - et al.
Autonomic and emotional responses to open and hidden stimulations of the human subthalamic region
Brain Res Bull
(2004) - et al.
Clinicians' expectations influence placebo analgesia
Lancet
(1985) - et al.
Expectation and dopamine release: mechanism of the placebo effect in Parkinson's disease
Science
(2001) - et al.
Placebo-responsive Parkinson patients show decreased activity in single neurons of subthalamic nucleus
Nat Neurosci
(2004) - et al.
Neuropharmacological dissection of placebo analgesia: expectation-activated opioid systems versus conditioning-activated specific sub-systems
J Neurosci
(1999) - et al.
Placebo and opioid analgesia—imaging a shared neuronal network
Science
(2002)
Placebo-induced changes in fMRI in the anticipation and experience of pain
Science
Placebo and naloxone can alter postsurgical pain by separate mechanisms
Nature
Influence of the method of drug administration on analgesic response
Nature
Open versus hidden medical treatments: the patient's knowledge about a therapy affects the therapy outcome. Prevention & Treatment 2003
Expectation modulates the response to subthalamic nucleus stimulation in Parkinsonian patients
Neuroreport
Conscious expectation and unconscious conditioning in analgesic, motor and hormonal placebo/nocebo responses
J Neurosci
Parallel organization of functionally segregated circuits linking basal ganglia and cortex
Annu Rev Neurosci
Basal ganglia-thalamocortical circuits: parallel substrates for motor, oculomotor, "prefrontal" and "limbic" functions
Prog Brain Res
Changes in cerebral activity pattern due to subthalamic nucleus or internal pallidum stimulation in Parkinson's disease
Ann Neurol
Transient acute depression induced by high-frequency deep-brain stimulation
N Engl J Med
Cited by (438)
Creating Placebo Nonresponders in the Lab
2024, Journal of PainPlacebos in pediatrics: A cross-sectional survey investigating physicians' perspectives
2023, Journal of Psychosomatic ResearchThe placebo component of pain treatments, towards an optimization of the effectiveness
2023, Actualites PharmaceutiquesPlacebo response in Raynaud's Phenomenon clinical trials: The prominent role of regression towards the mean: Placebo response in Raynaud's Phenomenon
2022, Seminars in Arthritis and RheumatismClinical relevance of nocebo effects in anesthesia practice: a narrative review
2024, Acta Anaesthesiologica Belgica