40 Hz Visual Stimulation as an Intervention in Schizophrenia

Condition(s) studied

Investigational drug(s) / intervention(s)

Visual stimulation: 40 Hz visual stimulation will be delivered at the same time of day over 5 consecutive days. Participants will lay down while wearing the customized sleep mask with inbuilt red LEDs flickering at 40 Hz linked to a microcontroller. Participants will be asked to keep their eyes closed and encouraged to fall asleep for the full stimulation duration of 60 minutes.

Study summary

In schizophrenia, an abnormal reduction in neuronal gamma oscillations (30-100 Hz) is associated with negative symptoms such as cognitive dysfunction. The literature suggests that rescuing gamma oscillations through non-invasive brain stimulation may be an accessible and safe add-on strategy to mitigate negative symptoms. Here, a stimulation protocol based on gamma visual stimulation will be tested. This pilot study will follow an uncontrolled clinical trial design: A minimum of ten patients diagnosed with schizophrenia or a schizoaffective disorder and predominant negative symptoms will be recruited at Klinikum rechts der Isar. They will undergo a multisession stimulation protocol, consisting of one hour of 40 Hz visual stimulation per day over five consecutive days, during which they will be encouraged to fall asleep. An equal number of patients will be recruited for a treatment-as-usual group without intervention. Pre- and post-assessments will include EEG, a cognitive test battery (THINC-IT), a mood scale (PANAS), and a schizophrenia symptom scale (PANSS). This study's results will inform on the feasibility of gamma visual stimulation as a potential add-on intervention in schizophrenia.

Eligibility

Primary outcome measure(s)

• Visually evoked neuronal 40 Hz activity represented in the frequency domain — Sessions 1 and 5 (first and last of the five stimulation days)
  Steady-State Visually Evoked Potentials (SSVEP) at 40 Hz as an electrophysiological measure of neuronal responses to 40 Hz visual stimulation, represented in the frequency domain. A higher signal-to-noise ratio value at 40 Hz (unit-free), ranging from zero to infinite, represents a larger neuronal response.
• Visually evoked neuronal 40 Hz activity represented in the time domain — Sessions 1 and 5 (first and last of the five stimulation days)
  Steady-State Visually Evoked Potentials (SSVEP) at 40 Hz as an electrophysiological measure of neuronal responses to 40 Hz visual stimulation, represented in the time domain. A larger peak-to-peak amplitude of the segment average in microvolts, ranging from zero to infinite, represents a larger neuronal response.

Trial sites (1)

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