eye movement desensitization and reprocessing eye movement desensitization and reprocessing eye movement desensitization and reprocessing (emdr) is a form of psychotherapy devised by francine shapiro in the 1980s that was originally designed to alleviate the distress associated with traumatic memories such as post-traumatic stress disorder (ptsd). emdr involves focusing on traumatic memories in a manner similar to exposure therapy while engaging in side-to-side eye movements. these eye movements have been criticized as having no scientific basis. the founder promoted the therapy for the treatment of ptsd and proponents employed untestable hypotheses to explain negative results in controlled studies. emdr has been characterized as a pseudoscientific purple hat therapy (i.e. only as effective as its underlying therapeutic methods without any contribution from its distinctive add-ons). emdr is recommended for the treatment of ptsd by various government and medical bodies citing varying levels of evidence, including the world health organization, the uk national institute for health and care excellence, the australian national health and medical research council, and the us departments of veteran affairs and defense. the us national institute of medicine found insufficient evidence to recommend it as of 2008. treatment guidelines note emdr effectiveness is statistically the same as trauma-focused behavioral therapy, and that this may be due to including most of the core elements of cbt. classification and technique emdr adds a number of non-scientific practices to exposure therapy. emdr is classified as one of the "power therapies" alongside thought field therapy, emotional freedom techniques and others – so called because these therapies are marketed as being superior to established therapies which preceded them. formal emdr therapy consists of eight phases. the first phase includes history taking and treatment planning. the second phase includes preparation. the third phase is an assessment phase followed by the fourth phase of desensitization. phases 5 and 6 involve installing positive cognitions and 'body scan". the last phase is the reevaluation phase. emdr is typically undertaken in a series of sessions with a trained therapist. the number of sessions can vary depending on the progress made. a typical emdr therapy session lasts from 60 to 90 minutes. trauma and ptsd the person being treated is asked to recall an image, phrase, and emotions that represent a level of distress related to a trigger while generating one of several types of bilateral sensory input, such as side-to-side eye movements or hand tapping. the 2013 world health organization practice guideline says that "like cognitive behavioral therapy (cbt) with a trauma focus, emdr aims to reduce subjective distress and strengthen adaptive beliefs related to the traumatic event. unlike cbt with a trauma focus, emdr does not involve (a) detailed descriptions of the event, (b) direct challenging of beliefs, (c) extended exposure or (d) homework." training shapiro was criticized for repeatedly increasing the length and expense of training and certification, allegedly in response to the results of controlled trials that cast doubt on emdr's efficacy. this included requiring the completion of an emdr training program in order to be qualified to administer emdr properly after researchers using the initial written instructions found no difference between no-eye-movement control groups and emdr-as-written experimental groups. further changes in training requirements and/or the definition of emdr included requiring level ii training when researchers with level i training still found no difference between eye-movement experimental groups and no-eye-movement controls and deeming "alternate forms of bilateral stimulation" (such as finger-tapping) as variants of emdr by the time a study found no difference between emdr and a finger-tapping control group. such changes in definition and training for emdr have been described as "ad hoc moves when confronted by embarrassing data". medical uses emdr is controversial within the psychological community. it is used by some practitioners for trauma therapy and in the treatment of complex post-traumatic stress disorder. effectiveness unusually for a pseudoscience, emdr has been subject to a number of randomized controlled trials. these have been summarized in systematic reviews, including: a cochrane systematic review comparing emdr with other psychotherapies in the treatment of chronic ptsd found emdr to be just as effective as tf-cbt and more effective than the other non-tf-cbt psychotherapies. caution was urged interpreting the results due to low numbers in included studies, risk of researcher bias, high drop-out rates, and overall "very low" quality of evidence for the comparisons with other psychotherapies. a 2016 systematic review and meta-analysis found that the effect size of emdr for ptsd is comparable to other evidence-based treatments, but that the strength of evidence was of a low quality, indicating that the effect sizes achieved are associated with substantial uncertainty. many randomized trials of emdr have been criticized for poor control groups, small sample sizes, and other methodological flaws. it has been called a purple hat therapy because any effectiveness is provided by the underlying therapy (or the standard treatment), not from emdr's distinctive features. there is some evidence that emdr can be as effective as trauma focused cognitive behavioral therapy (tf-cbt) for treating ptsd, though concerns have been raised about the poor quality of the underlying studies. in a 2022 systematic review of 13 studies, clients had mixed perceptions of the effectiveness of emdr therapy. medical guidelines the who's 2013 report on treating ptsd found "insufficient evidence" to support emdr for acute symptoms, but recommended it with moderate evidence for adults and low evidence for children in treating chronic symptoms. the uk national institute for health and care excellence's 2018 report on the treatment of ptsd found low-to-very-low evidence of efficacy for emdr in treating ptsd. the institute of medicine's 2008 report on the treatment of ptsd found insufficient evidence to recommend emdr, and criticized many of the available studies for methodological flaws including allegiance bias and insufficient controls. as of 2022, the american psychological association "conditionally recommends" emdr for the treatment of ptsd. the 2018 international society for traumatic stress studies practice guidelines "strongly recommend" emdr as an effective treatment for post-traumatic stress symptoms. the australian national health and medical research council recommends emdr for the treatment of ptsd in adults with its highest grade of evidence, noting that "emdr now includes most of the core elements of standard trauma-focussed cbt (tf-cbt)" and "the two variants of trauma-focussed therapy are not statistically different." a 2017 joint report from the us departments of veterans affairs and defense describes the evidence for emdr in the treatment of ptsd as "strong" (2017). the dutch national steering committee on mental health care has released multidisciplinary guidelines which describe "insufficient scientific evidence" to support emdr in the acute period following a stressful event (2008), but recommend emdr's use in chronic ptsd (2003). other conditions it is unclear whether emdr is of any benefit for treating mental health conditions in general and the evidence is insufficient to justify such use. the american psychological asssociation describes emdr as "ineffective" for the treatment of panic disorder. emdr has been found to cause strong effects on dissociative identity disorder patients, leading to recommendations for adjusted use. there is only weak evidence that emdr might be of benefit in treating depression. possible mechanisms incomplete processing of experiences in trauma many proposals of emdr efficacy share an assumption that, as shapiro posited, when a traumatic or very negative event occurs, information processing of the experience in memory may be incomplete. the trauma causes a disruption of normal adaptive information processing, which results in unprocessed information being dysfunctionally held in memory networks. according to the 2013 world health organization practice guideline: "this therapy is based on the idea that negative thoughts, feelings and behaviours are the result of unprocessed memories." this proposed mechanism has no known scientific basis. other mechanisms several other possible mechanisms have been proposed: emdr may impact working memory. if a patient performs bilateral stimulation task while remembering the trauma, the amount of information they can recall is thought to be reduced, making the resulting negative emotions less intense and more bearable. this is seen by some as a 'distancing effect'. the client is then believed to re-evaluate the trauma and process it in a less-harmful environment. this explanation is plausible, given research showing that memories are more modifiable once recalled. horizontal eye movement is thought to trigger an 'orienting response' in the brain, used in scanning the environment for threats and opportunities. the idea that eye movement prompts communication between the two sides of the brain. this idea is not grounded in accepted neuroscience. bilateral stimulation, including eye movement bilateral stimulation is a generalization of the left and right repetitive eye movement technique first used by shapiro. alternative stimuli include auditory stimuli that alternate between left and right speakers or headphones and physical stimuli such as tapping of the therapist's hands or tapping devices. most meta-analyses have found that the inclusion of bilateral eye-movements within emdr makes little or no difference to its effect. meta-analyses have also described a high risk of allegiance bias in emdr studies. one 2013 meta-analysis with fewer exclusion criteria found a moderate effect. pseudoscience emdr has been characterized as pseudoscience, because the underlying theory and primary therapeutic mechanism are unfalsifiable and non-scientific. emdr's founder and other practitioners have used untestable hypotheses to explain studies which show no effect. the results of the therapy are non-specific, especially if directed eye movements are irrelevant to the results. when these movements are removed, what remains is a broadly therapeutic interaction and deceptive marketing. according to yale neurologist steven novella: he false specificity of these treatments is a massive clinical distraction. time and effort are wasted clinically in studying, perfecting, and using these methods, rather than focusing on the components of the interaction that actually work. emdr has been characterised as a modern-day mesmerism, as the therapies have striking resemblances, from the sole inventor who devises the system while out walking, to the large business empire built on exaggerated claims. in the case of emdr, these have included the suggestions that emdr could drain violence from society and be useful in treating cancer and hiv/aids. psychology historian luis cordón has compared the popularity of emdr to that of other cult-like pseudosciences, facilitated communication and thought field therapy. a parody website advertising "sudotherapy" created by a fictional "fatima shekel" appeared on the internet in the 1990s. proponents of emdr described the website as libelous, since the website contained an image of a pair of shifting eyes following a cat named "sudo", and "fatima shekel" has the same initials as emdr's founder, francine shapiro. however, no legal action took place against the website or its founders, who are likely protected by american first amendment protections. history emdr was invented by francine shapiro (1948 – 2019) in the late 1980s. in a workshop, shapiro related how the idea of the therapy came to her while she was taking a walk in the woods, and discerned she had been able to cope better with disturbing thoughts when also experiencing saccadic eye movements. psychologist gerald rosen has expressed doubt about this description, saying that people are normally not aware of this type of eye movement. fuelled by marketing hype, emdr was taken up enthusiastically by therapists even while scientists remained skeptical; by the mid-2000s as many as 40,000 therapists had been trained. society and culture prince harry took a course of emdr and filmed a session for oprah winfrey during a mental health television documentary in 2021. producer and actress sandra bullock used emdr following a home invasion by a stalker in 2014.