Bilateral Stimulation (BLS): An Innovative Approach in Psychotherapy


Psychotherapy has experienced a series of evolutions and developments over the years, resulting in an array of innovative therapeutic approaches. One such technique that has garnered significant attention in recent years is Bilateral Stimulation (BLS). This article provides an in-depth exploration of BLS, its applications, benefits, and more.

What is Bilateral Stimulation (BLS)?

Bilateral Stimulation, commonly abbreviated as BLS, is a therapeutic technique used in psychotherapy, specifically in Eye Movement Desensitization and Reprocessing (EMDR) therapy, to help patients process distressing memories or thoughts. The approach involves alternately stimulating the right and left sides of the brain, often through eye movements, sounds, or tactile sensations.

The theory behind BLS is that by stimulating both hemispheres of the brain, therapists can help patients process and integrate traumatic memories. The result is a decrease in the emotional distress tied to these memories, fostering a healthier mental state (Shapiro, 2001).

How Does Bilateral Stimulation Work?

The idea behind BLS draws from the inherent connection between the brain’s physical and psychological functioning. The process engages the brain’s natural adaptive information processing (AIP) model, which helps individuals cope with and heal from psychological trauma.

In the context of EMDR therapy, BLS is used while the patient focuses on a distressing memory. As the patient moves their eyes back and forth under the therapist’s guidance (or experiences other forms of bilateral stimulation), the traumatic memory begins to lose its emotional charge. As a result, it becomes less distressing and more manageable, enabling the individual to process it more effectively (Solomon & Shapiro, 2008).

Different Types of Bilateral Stimulation

  1. Visual Bilateral Stimulation: The most commonly used form of BLS involves the patient moving their eyes from side to side under the direction of the therapist.
  2. Auditory Bilateral Stimulation: This involves alternating sounds in each ear, either through headphones or speakers.
  3. Tactile Bilateral Stimulation: This technique uses alternating tactile stimulation, like tapping on the patient’s hands or using handheld buzzers that vibrate alternately.

The specific type of BLS used often depends on the therapist’s judgment and the patient’s comfort and preference.

Applications of Bilateral Stimulation

BLS, primarily used in EMDR therapy, has shown its effectiveness in treating a wide array of psychological disorders, including but not limited to:

  • Post-Traumatic Stress Disorder (PTSD)
  • Anxiety disorders
  • Depression
  • Phobias
  • Obsessive-Compulsive Disorder (OCD)
  • Grief and loss
  • Panic attacks
  • Eating disorders

While originally developed to treat PTSD, the applications of EMDR, and consequently BLS, have expanded considerably, providing relief to many individuals struggling with various mental health issues.

The Science Behind Bilateral Stimulation

Research into the effectiveness of BLS as part of EMDR therapy has shown promising results. According to the EMDR Institute, multiple controlled studies have demonstrated the efficacy of EMDR therapy in treating PTSD (EMDR Institute, Inc., n.d.).

A study published in the Journal of Clinical Psychology found that 84-90% of single-trauma victims no longer had PTSD after only three 90-minute sessions of EMDR therapy (Marcus et al., 1997).

Another study from the Journal of Traumatic Stress showed that EMDR therapy was effective in reducing symptoms of PTSD and depression in adult survivors of childhood sexual abuse (Edmond et al., 2004).

While these studies show the efficacy of EMDR therapy as a whole, it’s important to note that BLS is a key component of this therapy.

Potential Side Effects and Risks of Bilateral Stimulation

Like any therapeutic technique, BLS is not without its potential side effects. Some individuals may experience light-headedness, nausea, or discomfort during the eye movement process. Others may find that disturbing memories surface outside of therapy sessions. It’s essential to have a skilled therapist who can guide the patient through these experiences and ensure they have appropriate coping mechanisms in place.

Final Thoughts

Bilateral Stimulation, a core component of EMDR therapy, offers an innovative approach to treat a range of psychological disorders. It capitalizes on the brain’s inherent ability to heal, providing a promising tool for those struggling with trauma and other distressing experiences.

If you are considering psychotherapy that employs BLS, it’s important to consult with a mental health professional who can provide guidance based on your unique needs and circumstances.


  • Shapiro, F. (2001). Eye Movement Desensitization and Reprocessing (EMDR): Basic Principles, Protocols, and Procedures (2nd ed.). Guilford Press.
  • Solomon, R. M., & Shapiro, F. (2008). EMDR and the Adaptive Information Processing Model. Journal of EMDR Practice and Research, 2(4), 315-325.
  • EMDR Institute, Inc. (n.d.). Research Overview.
  • Marcus, S., Marquis, P., & Sakai, C. (1997). Controlled study of treatment of PTSD using EMDR in an HMO setting. Psychotherapy: Theory, Research, Practice, Training, 34(3), 307-315.
  • Edmond, T., Sloan, L., & McCarty, D. (2004). Sexual abuse survivors’ perceptions of the effectiveness of EMDR and eclectic therapy: A mixed-methods study. Research on Social Work Practice, 14(4), 259-272.