Transcranial Infrared Laser Stimulation (TILS) of Prefrontal Cognition in Post-traumatic Stress Disorder (PTSD)

Not Applicable

Terminated

Brief Summary: This study evaluates the effects of transcranial infrared laser stimulation (TILS) on prefrontal metabolism and hemodynamics in veterans with post-traumatic stress disorder (PTSD). The subjects will receive six TILS interventions and one sham intervention in a course of seven weeks.

Detailed Description: Post-traumatic stress disorder (PTSD) is often associated with cognitive impairments. It has been indicated that hypoactivity of the prefrontal cortex plays a major role in the disrupted neural circuitry of mood and cognition.

Transcranial infrared laser stimulation (TILS) is a neural type of photobiomodulation that can elevate neuronal metabolism by exciting cytochrome c oxidase (CCO). Veterans with PTSD will receive prefrontal TILS interventions once-per-week for six weeks. They will also receive an additional sham intervention (laser power = 0) that will be randomly assigned into the first two sessions. Broadband near-infrared spectroscopy (bbNIRS) will be used to directly assess the CCO changes during every TILS/sham session.

Veterans' prefrontal functions will be evaluated with short-term memory tasks before and after each intervention. The prefrontal activities will also be imaged by functional near-infrared spectroscopy (fNIRS) to objectively assess the functional changes due to TILS/sham interventions.

Recruitment & Eligibility

Inclusion Criteria

War-zone and non-war-zone veterans
Ages 18-60 years old
Males and females
Able to read, speak, and understand English
Medical records showing prior diagnosis of PTSD (here it refers to the records prior to TILS, which will be assessed and obtained in Visit 1)
Medical records showing diagnosis of PTSD (here it refers to the CAPS-5 record prior to TILS, which will be assessed and obtained in Visit 1)
On stable doses of any psychotropic medications for at least 4 weeks

Exclusion Criteria

Significant physical disability to perform a computerized memory task
Past/current significant medical/neurological/mental health disorders known to affect cognitive functioning (e.g., stroke, dementia, schizophrenia, AIDS)
Presence of moderate/severe TBI, defined as having: alteration of consciousness/mental state >24 hours; posttraumatic amnesia >1 day; loss of consciousness >30 minutes; and/or abnormal structural neuroimaging. We will not exclude veterans with mild TBI, which is found in nearly 50% of veterans with PTSD
Alcohol abuse/dependence for the past 12- months, as determined by the Rapid Alcohol Problems Screen score >0
Drug abuse/dependence for the past 12- months, as determined by the Drug Abuse Screening Test-10 score >2
Severe depression (PHQ-9 total score >19), significant risk of suicide (SBQ-R >6), severe headache (PHQ-15, Item e =2), and/or severe dizziness (PHQ-15, Item g =2)
Opiate use in the month prior to study entry

Arm && Interventions

Group	Intervention	Description
One TILS, one sham, and then five TILS interventions	TILS	Participants first received a TILS intervention, followed by a sham session one week later. Then, participants received another five weekly TILS interventions.
One TILS, one sham, and then five TILS interventions	sham	Participants first received a TILS intervention, followed by a sham session one week later. Then, participants received another five weekly TILS interventions.
One sham, then six TILS interventions	sham	Participants first received a sham session, followed by six weekly TILS sessions.
One sham, then six TILS interventions	TILS	Participants first received a sham session, followed by six weekly TILS sessions.

Primary Outcome Measures

Name	Time	Method
Cerebral CCO Changes in Response to TILS and Sham	7 weeks	Cerebral CCO changes measured by broadband NIRS during six TILS interventions and one sham session.
Cerebral Hemodynamic Changes in Response to TILS and Sham	7 weeks	Cerebral hemodynamic changes measured by broadband NIRS during every TILS or sham session

Secondary Outcome Measures

Name	Time	Method
Prefrontal Activations in Short-term Memory Processing	8 weeks	Anterior prefrontal hemodynamic activations (HbO2 and Hb changes) measured by functional NIRS during the Digit Forward (DF) and Digit Backward (DB) tasks. The activations were recorded from initial baseline, and after the one sham and six TILS sessions. In post-experiment processing, the activations were averaged in the recall phase, which was a key component related to PTSD.
Short-term Memory Scores	8 weeks	The participant's recall time in Digit Forward (DF) task and Digit Backward (DB) task was recorded recorded during initial baseline, and after the one sham and six TILS sessions. The recall time indicates how fast the participants could recall that digital numbers 10 seconds after they vanished on computer screen.