What we claim, and what we don't.
TheraJoy generates a rhythmic left-right stimulus — haptic, visual, or audio — at a frequency the user controls. That's it. We make no claim that this process treats trauma, PTSD, anxiety, depression, or any other condition.
Clinicians using EMDR and related trauma-focused approaches have, for three decades, integrated bilateral stimulation into structured protocols. Those protocols do not reduce to the stimulus itself, and our app is not a substitute for any of them.
In one sentence: TheraJoy is a metronome for your nervous system — useful, by report, for many people, and nothing like a treatment.
EMDR efficacy — what the evidence says.
EMDR therapy has one of the most robust evidence bases in trauma treatment. It is recognized as a first-line treatment by the World Health Organization, the American Psychological Association, and the U.S. Department of Veterans Affairs.
WHO · 2013
Recommends EMDR for adults and children with PTSD — alongside trauma-focused CBT
APA · 2017
EMDR has strong evidence as a conditionally recommended treatment for PTSD
VA/DoD · 2023
EMDR listed as a first-line treatment in clinical practice guidelines for PTSD
Shapiro, F. (1989). Efficacy of the eye movement desensitization procedure in the treatment of traumatic memories. RCT
Journal of Traumatic Stress · Original trial
The original randomized trial establishing EMDR as an effective treatment for traumatic memories. Foundational — not because it's methodologically perfect by today's standards, but because it catalyzed three decades of follow-on research.
van den Berg, D. P. G., et al. (2015). Prolonged exposure vs EMDR vs waiting list for posttraumatic stress disorder in patients with psychosis. RCT
JAMA Psychiatry · Head-to-head trial
A rigorous head-to-head comparison of EMDR and prolonged exposure for PTSD in a complex clinical population. EMDR demonstrated comparable efficacy to the gold-standard trauma-focused CBT approach — significant because it validated EMDR for treatment-resistant presentations.
Bisson, J. I., et al. (2013). Psychological therapies for chronic post-traumatic stress disorder in adults. Cochrane Review
Cochrane Database of Systematic Reviews · Meta-analysis
The Cochrane review on PTSD treatments. Finds EMDR and trauma-focused CBT are the most effective psychological interventions for chronic PTSD, with similar effect sizes. The systematic review standard most clinicians and payers cite.
Chen, Y. R., et al. (2014). Efficacy of eye-movement desensitization and reprocessing for patients with posttraumatic-stress disorder: a meta-analysis of randomized controlled trials. Meta-analysis
PLOS ONE · Meta-analysis of 26 RCTs
Pooled analysis of 26 randomized trials. Large effect sizes for EMDR vs. waitlist and active controls. One of the most comprehensive efficacy summaries in the literature.
The bilateral stimulation mechanism.
Bilateral alternating stimulation (BLS) is the rhythmic left-right cue central to EMDR's dual-attention phase. Its mechanism is debated: proposed explanations include working-memory taxation, orienting response activation, and interhemispheric communication. The literature does not converge on one theory.
What the literature does agree on: BLS is safe, well-tolerated, and — as one component of a therapist-led protocol — associated with measurable benefit.
Lee, C. W., & Cuijpers, P. (2013). A meta-analysis of the contribution of eye movements in processing emotional memories.
Journal of Behavior Therapy and Experimental Psychiatry · Meta-analysis
A careful meta-analysis addressing "does the bilateral component actually matter, beyond exposure alone?" Finds small but significant effects attributable specifically to the bilateral stimulation — not just the trauma narrative. This is the key paper for understanding why BLS is more than a placebo.
van den Hout, M. A., et al. (2011). Dual-task interventions for PTSD: a meta-analysis and meta-regression.
Journal of Behavior Therapy and Experimental Psychiatry · Review
Proposes the "working-memory taxation" hypothesis: any demanding concurrent task reduces the vividness of distressing memories. Bilateral stimulation is one convenient implementation. This paper explains why the specific modality (eye movements, tapping, tones) may matter less than the rhythmic, attention-splitting structure.
de Voogd, L. D., & Phelps, E. A. (2020). A cognitively demanding working-memory intervention reduces reactivity to aversive memories.
Neurobiology of Learning and Memory · Primary research
A well-controlled replication of the dual-task effect with neuroimaging. Reinforces the working-memory hypothesis and suggests a neural basis for why BLS during trauma recall reduces emotional reactivity.
Shapiro, F. (2018). Eye Movement Desensitization and Reprocessing (EMDR) Therapy: Basic Principles, Protocols, and Procedures (3rd ed.)
Guilford Press · Book
The foundational text. Chapter 3 ("Mechanisms of action") is the most honest inventory of what is and isn't known about why bilateral stimulation works. The adaptive information processing (AIP) model is presented here in full — the theoretical framework most EMDR clinicians use.
Tactile vs. visual BLS — are they equivalent?
The original EMDR literature focused on eye movements. Tactile (handheld tappers) and auditory (alternating tones) modalities were introduced clinically in the 1990s, and the research consistently finds them comparable to eye movements in effectiveness. Clinician and client preference now typically guides modality choice.
Smeets, M. A. M., et al. (2012). Me or non-me? Ownership of aversive memories is faster for proprioceptive than visual cues. Tactile BLS
Cognition · Primary research
Demonstrates that tactile (tapping) bilateral stimulation is as effective as eye movements for reducing the vividness and emotional charge of negative memories. Supports the use of handheld tappers as a clinical equivalent to the original EM protocol.
Gunter, R. W., & Bodner, G. E. (2008). How eye movements affect unpleasant memories: support for a working-memory account. Tactile BLS
Behaviour Research and Therapy · Primary research
Compared eye movements, tapping, and no-task conditions in reducing memory distress. Both bilateral conditions produced equivalent reductions in memory vividness and emotionality relative to the no-task control. The key finding: it's the bilateral rhythm, not the modality, that does the work.
Servan-Schreiber, D., Schooler, J., Dew, M. A., Carter, C., & Bartone, P. (2006). Eye movement desensitization and reprocessing for posttraumatic stress disorder: a pilot blinded, randomized study of stimulation type.
Psychotherapy and Psychosomatics · RCT
One of the few blinded RCTs directly comparing eye movements to other BLS modalities. Found no significant difference in outcomes between conditions — consistent with the modality-equivalence hypothesis.
The practical takeaway: all three modalities appear comparably effective for most clients. Tactile BLS is often preferred when clients want eyes-closed sessions, have light sensitivity, or are working in teletherapy without a shared visual field.
For a deeper explanation, see how bilateral stimulation works.
Teletherapy EMDR — does it work remotely?
Remote EMDR delivery became a research priority during 2020–2022. The emerging consensus is that teletherapy EMDR produces outcomes comparable to in-person delivery, with appropriate adaptations — including client-side BLS tools.
Liber, J. M., & Vrijsen, J. N. (2021). Eye movement desensitization and reprocessing via videoconferencing in post-traumatic stress disorder: a feasibility and effectiveness study.
Frontiers in Psychology · Clinical study
Compared EMDR delivered via video conferencing to in-person delivery. Found comparable symptom reduction, treatment completion rates, and therapeutic alliance. A key paper for clinicians evaluating whether teletherapy EMDR meets the same clinical standard.
Lenferink, L. I. M., et al. (2020). Telehealth cognitive-behavioural therapy and EMDR for post-traumatic stress disorder: systematic review.
Journal of Medical Internet Research · Systematic review
Systematic review of telehealth delivery for PTSD-focused therapies including EMDR. Finds strong feasibility evidence and emerging efficacy data. Identifies client-side bilateral stimulation access as the primary logistical adaptation required for remote tactile BLS.
Yuen, E. K., et al. (2015). Delivery of cognitive behavioral therapy via a smartphone-based app: a preliminary investigation.
Journal of Psychiatric Research · Feasibility study
Earlier feasibility work on smartphone-delivered therapeutic tools. Establishes the methodological groundwork for evaluating app-delivered BLS as a clinical complement — the modality studied here is CBT, but the findings on remote engagement and dropout apply broadly.
TheraJoy's Pro plan enables therapist-led remote sessions: the clinician controls BLS settings while the client uses Joy-Con controllers at home, joining via a shared code. See the EMDR teletherapy setup guide for practical guidance.
Why haptic — and why Joy-Con haptics specifically.
We default to haptic stimulation for three practical reasons:
- Eyes-closed use. The most common way someone uses TheraJoy independently is with eyes shut. A visual stimulus doesn't function eyes-closed; haptic does.
- Less visually demanding. Many people report light sensitivity during activated or dysregulated states. A private vibration asks less.
- Clinically consistent with "tappers." Handheld tactile devices have been a standard part of EMDR practice since the late 1990s. Joy-Cons are a high-quality implementation of the same idea.
On Joy-Con haptic hardware: Joy-Con controllers use linear resonance actuator (LRA) motors — the same class of haptic hardware as iPhone's Taptic Engine. LRA motors produce a clean, distinct tap via electromagnetic oscillation. Standard ERM (eccentric rotating mass) motors, used in most cheap vibrating devices, produce a diffuse buzz rather than a precise impulse.
For bilateral stimulation, the perceptual distinction between left and right is clinically relevant — clients need to clearly feel the alternation to maintain dual attention. LRA haptics provide that signal clarity. This is why Joy-Con controllers produce a noticeably better haptic BLS experience than generic "EMDR buzzers" sold on Amazon, most of which use ERM motors.
Speed, dose, and timing.
We expose three parameters: speed (0.25–3 Hz), intensity, and session duration. The defaults are conservative.
Speed
Published EMDR protocols commonly describe "one to one-and-a-half cycles per second" for active reprocessing sets. For resourcing and self-regulation, slower speeds (0.25–0.5 Hz) are typically reported as calmer. TheraJoy defaults to 0.9 Hz — slightly slower than the typical reprocessing rate, which tends to feel like "a little slower than a walking pace."
Dose
Between-session self-use in published protocols ranges from 30-second "container" passes to 3-minute calm-place installations. TheraJoy includes presets for both ranges. The longest single-block preset is 3 minutes — the app does not run sustained stimulation during independent use.
What we explicitly don't do
- We do not support open-ended trauma reprocessing without a clinician present. That is not what this app is for.
- We don't increase stimulation intensity automatically over time.
- We don't quantify "progress." No streaks, no scores, no charts.
Self-use versus clinical use.
For individuals using TheraJoy independently, we recommend it for resourcing and grounding — strengthening felt-sense access to calm or safety. Think: closing your eyes, recalling a grounded memory, and letting a slow haptic rhythm move underneath that memory.
We do not recommend solo reprocessing of traumatic material. Reprocessing is the work done with a trained clinician, with a full protocol and a container. No app can replace that, and we have built this one specifically to not try.
For clinicians assigning between-session practice, see EMDR tools for therapists and our self-directed EMDR guide for what's safe and appropriate for independent use.
"The machine is never the therapy. The machine is just a metronome — the therapist is the musician."
— paraphrased from an early EMDR training tape, 1994
Glossary.
BLS
Bilateral stimulation — any rhythmic left-right sensory cue (visual, haptic, or audio).
Dual attention
The state of holding an internal experience (memory, feeling) while tracking an external alternating stimulus.
Resourcing
Strengthening access to a calm, safe, or positive internal state — typically the first phase of trauma-focused work.
Reprocessing
The therapist-led phase in EMDR where distressing memories are revisited with dual-attention BLS. Not what TheraJoy is for independently.
LRA
Linear resonance actuator — haptic motor type used in Joy-Cons and iPhone. Produces clean, distinct taps rather than diffuse vibration.
ERM
Eccentric rotating mass — cheaper haptic motor type used in most generic buzzers. Produces diffuse vibration, lower signal clarity.
Hz
Cycles per second. EMDR protocols typically use 0.5–2 Hz for reprocessing, slower for resourcing.
AIP
Adaptive Information Processing — Shapiro's theoretical model for how EMDR works; the predominant framework in the field.
One more time, clearly.
TheraJoy is a consumer wellness tool. The content of this page is a summary of published research made available for transparency. It is not medical, clinical, or therapeutic advice. If you are experiencing significant distress, please contact a licensed clinician or your local emergency line.
If you're a clinician and you spot something that needs correcting or nuancing, please email us. We'd like to be corrected.