NCT04683640: LAMPS

Latent Aging Mechanisms in Pain and Sleep

Completed Phase 2 Results posted Last updated 18 July 2025

What this trial tests

Phase 2 trial testing GABA in Chronic Pain in 33 participants. Completed in 30 May 2024.

Timeline

2 April 2021

Primary endpoint
30 May 2024

30 May 2024

Quick facts

Lead sponsor	University of Florida
Phase	Phase 2
Status	Completed
Study type	INTERVENTIONAL
Allocation	randomized
Design	parallel
Masking	double
Primary purpose	basic science
Enrollment	33
Start date	2 April 2021
Primary completion	30 May 2024
Estimated completion	30 May 2024
Sites	1 location across United States

Drugs / interventions tested

• GABA (aminobutyric acid) — full drug profile →
• Placebo

Conditions studied

• Chronic Pain — all drugs for Chronic Pain →

Sponsor

University of Florida

Who can join

Adults 45 to 100, any sex, with Chronic Pain. Patients with the condition only — healthy volunteers not accepted.

Results — posted to ClinicalTrials.gov

Per-arm endpoint measurements with 95% confidence intervals where reported. Source: trial results section.

The Pittsburgh Sleep Quality Index (PSQI): PSQI Total Score at Baseline Primary · PSQI was administered at baseline

The Pittsburgh Sleep Quality Index (PSQI) is a self-report questionnaire that assesses sleep quality over the past month. It consists of 19 items grouped into seven components. Each component is scored from 0 to 3, and the component scores are summed to yield a global total score ranging from 0 to 21. Higher scores indicate worse sleep quality. A total score greater than 5 is typically used to distinguish poor sleepers from good sleepers.

Group	Value	95% CI
PLACEBO	11.20	± 4.18
GABA	9.78	± 3.02

The Pittsburgh Sleep Quality Index (PSQI): PSQI Total Score at Post-Intervention Primary · PSQI was administered immediately after completing the 4-week intervention

The Pittsburgh Sleep Quality Index (PSQI) is a self-report questionnaire that assesses sleep quality over the past month. It consists of 19 items grouped into seven components. Each component is scored from 0 to 3, and the component scores are summed to yield a global total score ranging from 0 to 21. Higher scores indicate worse sleep quality. A total score greater than 5 is typically used to distinguish poor sleepers from good sleepers.

Group	Value	95% CI
PLACEBO	8.08	± 3.59
GABA	7.89	± 3.23

Verbal Descriptor Scale (VDS) at Baseline Primary · VDS was administered at baseline

The Verbal Descriptor Scale (VDS) is a validated self-report measure of pain intensity, commonly used in older adults. Participants are asked to select the descriptor that best represents their current pain level from six options: No pain, Mild, Moderate, Severe, Very severe, and Worst possible pain. Each descriptor corresponds to a numeric value from 0 to 5, with higher scores indicating greater pain intensity.

Group	Value	95% CI
PLACEBO	2.00	1 – 2
GABA	1.50	1 – 2

Verbal Descriptor Scale (VDS) at Post-Intervention Primary · VDS was administered immediately after completing the 4-week intervention

The Verbal Descriptor Scale (VDS) is a validated self-report measure of pain intensity, commonly used in older adults. Participants are asked to select the descriptor that best represents their current pain level from six options: No pain, Mild, Moderate, Severe, Very severe, and Worst possible pain. Each descriptor corresponds to a numeric value from 0 to 5, with higher scores indicating greater pain intensity.

Group	Value	95% CI
PLACEBO	1	0.50 – 2
GABA	1	1 – 2

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at Baseline Primary · WOMAC was administered at baseline.

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a validated self-report questionnaire that assesses pain, stiffness, and physical function in individuals with musculoskeletal conditions. It includes 24 items scored on a 5-point Likert scale (0 = none to 4 = extreme), producing subscale scores and a total score. The total WOMAC score ranges from 0 to 96, with higher scores indicating worse symptoms and functional limitations.

Group	Value	95% CI
PLACEBO	33.83	± 18.98
GABA	34.77	± 18.61

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) at Post-Intervention Primary · WOMAC was administered after completing the 4-week intervention

The Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) is a validated self-report questionnaire that assesses pain, stiffness, and physical function in individuals with musculoskeletal conditions. It includes 24 items scored on a 5-point Likert scale (0 = none to 4 = extreme), producing subscale scores and a total score. The total WOMAC score ranges from 0 to 96, with higher scores indicating worse symptoms and functional limitations.

Group	Value	95% CI
PLACEBO	22.92	± 17.98
GABA	34.87	± 19.41

Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Total Score at Baseline Secondary · Baseline

The Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) is a validated 22-item self-report instrument that assesses the multidimensional experience of pain. Items are grouped into four subscales-continuous, intermittent, neuropathic, and affective pain-and each item is rated from 0 (no pain) to 10 (worst possible pain) based on pain intensity over the past week. The total score is calculated as the average of all 22 item scores, with higher scores indicating greater pain severity.

Group	Value	95% CI
PLACEBO	2.41	± 1.63
GABA	2.21	± 1.62

Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) Total Score at Post-Intervention Secondary · Immediately post-intervention (4 weeks)

The Short-Form McGill Pain Questionnaire-2 (SF-MPQ-2) is a validated 22-item self-report instrument that assesses the multidimensional experience of pain. Items are grouped into four subscales-continuous, intermittent, neuropathic, and affective pain-and each item is rated from 0 (no pain) to 10 (worst possible pain) based on pain intensity over the past week. The total score is calculated as the average of all 22 item scores, with higher scores indicating greater pain severity.

Group	Value	95% CI
PLACEBO	1.43	± 1.14
GABA	1.77	± 1.36

Pain Detect at Baseline Secondary · Baseline

The PainDETECT Questionnaire is a validated self-report instrument used to assess the likelihood of a neuropathic pain component in individuals with chronic pain. It includes 9 items that assess pain intensity, pain patterns, and sensory descriptors. The total score ranges from -1 to 38, with higher scores indicating a greater probability of neuropathic pain. A score ≥19 suggests likely neuropathic pain, 13-18 indicates possible neuropathic pain, and ≤12 suggests that neuropathic pain is unlikely.

Group	Value	95% CI
PLACEBO	9.23	± 5.70
GABA	9.39	± 6.89

Pain Detect at Post-Intervention Secondary · Immediately post-intervention (4 weeks)

The PainDETECT Questionnaire is a validated self-report instrument used to assess the likelihood of a neuropathic pain component in individuals with chronic pain. It includes 9 items that assess pain intensity, pain patterns, and sensory descriptors. The total score ranges from -1 to 38, with higher scores indicating a greater probability of neuropathic pain. A score ≥19 suggests likely neuropathic pain, 13-18 indicates possible neuropathic pain, and ≤12 suggests that neuropathic pain is unlikely.

Group	Value	95% CI
PLACEBO	6.54	± 5.17
GABA	8.33	± 6.27

Functional Outcomes of Sleep Questionnaire - 10 Items (FOSQ-10) at Baseline Secondary · Baseline

The Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10) is a 10-item self-report instrument that assesses the impact of excessive daytime sleepiness on daily functioning across five domains. Each item is rated on a 4-point Likert scale from 1 (extreme difficulty) to 4 (no difficulty). The total score is calculated by averaging items within each domain and summing the domain means. Total scores range from 5 to 20, with higher scores indicating better functional status and less impairment.

Group	Value	95% CI
PLACEBO	17.54	± 1.28
GABA	16.58	± 2.84

Functional Outcomes of Sleep Questionnaire - 10 Items (FOSQ-10) at Post-Intervention Secondary · Immediately post-intervention (4 weeks)

The Functional Outcomes of Sleep Questionnaire-10 (FOSQ-10) is a 10-item self-report instrument that assesses the impact of excessive daytime sleepiness on daily functioning across five domains. Each item is rated on a 4-point Likert scale from 1 (extreme difficulty) to 4 (no difficulty). The total score is calculated by averaging items within each domain and summing the domain means. Total scores range from 5 to 20, with higher scores indicating better functional status and less impairment.

Group	Value	95% CI
PLACEBO	12.60	± 2.70
GABA	12.48	± 2.65

Adverse events — posted to ClinicalTrials.gov

Time frame: From the start of the intervention through 3 months post-intervention. Adverse events were actively monitored weekly during the 4-week treatment phase and followed up for an additional 3 months after study completion. Reporting threshold: 0%. Adverse-event reports describe events observed during the trial — not all are caused by the drug.

PLACEBO

Serious: 0/15 (0%)

Deaths: 0/15

GABA

Serious: 0/18 (0%)

Deaths: 0/18

Other adverse events (24 terms — click to expand)

Reaction	System	PLACEBO	GABA
Fatigue	General disorders	—	—
Drowsiness/sleepiness	Nervous system disorders	—	—
Balance problems	Nervous system disorders	—	—
Dry throat	Respiratory, thoracic and mediastinal disorders	—	—
Feelings of stress or anxiety	Psychiatric disorders	—	—
Light-headedness/vertigo	Nervous system disorders	—	—
Constipation	Gastrointestinal disorders	—	—
Abdominal/stomach pain	Gastrointestinal disorders	—	—
Changes in mood	Psychiatric disorders	—	—
Blurred vision	Eye disorders	—	—
Heart rate changes/palpitations	Cardiac disorders	—	—
Skin rash/itching	Skin and subcutaneous tissue disorders	—	—
Change in appetite	Metabolism and nutrition disorders	—	—
Nausea/vomiting	Gastrointestinal disorders	—	—
Changes in blood pressure	Vascular disorders	—	—
Shortness of breath	Respiratory, thoracic and mediastinal disorders	—	—
Back pain	Musculoskeletal and connective tissue disorders	—	—
Causing difficulty sleeping longer	Social circumstances	—	—
Glucose high/ thirsty	Endocrine disorders	—	—
Left shoulder pain	Musculoskeletal and connective tissue disorders	—	—
Right leg cramps	Musculoskeletal and connective tissue disorders	—	—
Tinnitus	Ear and labyrinth disorders	—	—
Diarrhea	Gastrointestinal disorders	—	—
Tired	General disorders	—	—

Data from ClinicalTrials.gov NCT04683640 adverse events section.

Sponsor's own description

Chronic pain is a serious public health problem in older adults depending on the pain condition, and the capacity to sleep properly changes with age. Given the potential mechanistic role of GABA (gamma-aminobutyric acid) in both conditions, based on our preliminary data, this proposal will determine the effect of oral GABA administration in sleep quality and pain in older adults with chronic pain and sleep disorders as well as to characterize the potential neurobiological mechanisms involved in both illnesses.

Publications & conference data

1 peer-reviewed publication reference this trial (live from Europe PMC):

1. Protocol for a pilot and feasibility randomized-controlled trial of four weeks of oral γ-aminobutyric acid (GABA) intake and its effect on pain and sleep in middle-to-older aged adults.
   Montesino-Goicolea S, Nin O, Gonzalez BM, Sawczuk NJ, et al · · 2023 · cited 3× · PMID 36712186 · DOI 10.1016/j.conctc.2023.101066