Trial Outcomes & Findings for Buspirone for the Treatment of Traumatic Brain Injury (TBI) Irritability and Aggression (NCT NCT01821690)

NCT ID: NCT01821690

Last Updated: 2026-02-24

Results Overview

Neuropsychiatric Inventory (NPI) is a 40-item instrument evaluating 12 behavioral domains with prior use in TBI. NPI-Irritability domain (NPI-I) encompasses temper outbursts, mood fluctuations, abrupt anger, impatience, irritable disposition, and argumentative behavior. Assessment involves identifying if these behaviors are present and then scoring the most concerning manifestation on severity (1=mild to 3=severe) and frequency (1-4 scale, higher=greater occurrence). Domain totals (0-12 range) represent the product of severity and frequency ratings for the predominant symptom.

Recruitment status

COMPLETED

Study phase

PHASE4

Target enrollment

81 participants

Primary outcome timeframe

Day 91

Results posted on

2026-02-24

Participant Flow

Recruitment occurred from May 2013 through September 2025 via support groups, physician correspondence, clinical referrals, and newsletters.

Subject's observers were not enrolled.

Participant milestones

Participant milestones
Measure
Buspirone Treatment
Buspirone starting at 15 mg/day and titrated up to 60 mg/day as prescribed and tolerated. Buspirone used flexible-dose, response-guided titration starting at 15 mg daily, titrated up to 60 mg daily in divided doses. On Day 8, dose automatically increased to 30 mg daily. Dose increased by 15 mg increments at days 35 and 63 if observer-rated NPI-Irritability had not decreased by ≥80% from baseline; dose maintained if ≥80% decrease achieved.
Buspirone Placebo
Placebo tablets as prescribed. Buspirone and placebo were identically matched in container labeling, appearance, and sensory properties. Placebo participants underwent identical sham titration.
Overall Study
STARTED
41
40
Overall Study
COMPLETED
38
40
Overall Study
NOT COMPLETED
3
0

Reasons for withdrawal

Withdrawal data not reported

Baseline Characteristics

Buspirone for the Treatment of Traumatic Brain Injury (TBI) Irritability and Aggression

Baseline characteristics by cohort

Baseline characteristics by cohort
Measure
Buspirone Treatment
n=41 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Total
n=81 Participants
Total of all reporting groups
Age, Continuous
41.5 years
STANDARD_DEVIATION 14.0 • n=58 Participants
40.2 years
STANDARD_DEVIATION 14.3
40.9 years
STANDARD_DEVIATION 14.1 • n=1 Participants
Sex: Female, Male
Female
14 Participants
n=58 Participants
12 Participants
26 Participants
n=1 Participants
Sex: Female, Male
Male
27 Participants
n=58 Participants
28 Participants
55 Participants
n=1 Participants
Race/Ethnicity, Customized
White
39 Participants
n=58 Participants
35 Participants
74 Participants
n=1 Participants
Race/Ethnicity, Customized
Black
2 Participants
n=58 Participants
4 Participants
6 Participants
n=1 Participants
Race/Ethnicity, Customized
Other
0 Participants
n=58 Participants
1 Participants
1 Participants
n=1 Participants
Neuropsychiatric Inventory-Irritability (NPI-I) -- Observer-rated
8.1 Scores on a scale
STANDARD_DEVIATION 2.6 • n=58 Participants
7.6 Scores on a scale
STANDARD_DEVIATION 2.6
7.9 Scores on a scale
STANDARD_DEVIATION 2.6 • n=1 Participants
Neuropsychiatric Inventory-Aggression (NPI-A) -- Observer-rated
6.7 Score
STANDARD_DEVIATION 3.5 • n=58 Participants
6.0 Score
STANDARD_DEVIATION 3.2
6.3 Score
STANDARD_DEVIATION 3.3 • n=1 Participants
TBI-Quality of Life -- Participant-rated
59.9 T-score
STANDARD_DEVIATION 7.3 • n=58 Participants
58.8 T-score
STANDARD_DEVIATION 9.1
59.4 T-score
STANDARD_DEVIATION 8.2 • n=1 Participants
Personal Health Questionnaire (PHQ)-9 - Participant-rated
9.8 Score
STANDARD_DEVIATION 5.6 • n=58 Participants
8.6 Score
STANDARD_DEVIATION 5.3
9.2 Score
STANDARD_DEVIATION 5.5 • n=1 Participants
General Anxiety Disorder (GAD-7) - Participant-rated
8.9 Score
STANDARD_DEVIATION 5.0 • n=58 Participants
8.7 Score
STANDARD_DEVIATION 6.3
8.8 Score
STANDARD_DEVIATION 5.7 • n=1 Participants
Neuropsychiatric Inventory-Irritability (NPI-I) -- Participant-rated
6.4 Scores on a scale
STANDARD_DEVIATION 3.2 • n=58 Participants
6.0 Scores on a scale
STANDARD_DEVIATION 3.6
6.2 Scores on a scale
STANDARD_DEVIATION 3.4 • n=1 Participants
Neuropsychiatric Inventory-Aggression (NPI-A) -- Participant-rated
5.5 Score
STANDARD_DEVIATION 3.6 • n=58 Participants
4.8 Score
STANDARD_DEVIATION 3.7
5.1 Score
STANDARD_DEVIATION 3.6 • n=1 Participants

PRIMARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

Neuropsychiatric Inventory (NPI) is a 40-item instrument evaluating 12 behavioral domains with prior use in TBI. NPI-Irritability domain (NPI-I) encompasses temper outbursts, mood fluctuations, abrupt anger, impatience, irritable disposition, and argumentative behavior. Assessment involves identifying if these behaviors are present and then scoring the most concerning manifestation on severity (1=mild to 3=severe) and frequency (1-4 scale, higher=greater occurrence). Domain totals (0-12 range) represent the product of severity and frequency ratings for the predominant symptom.

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Neuropsychiatric Inventory-Irritability Domain - Observer-rated Proportion Improved ≥ 3 Points Baseline to Day-91
30 Participants
31 Participants

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

Neuropsychiatric Inventory (NPI) is a 40-item instrument evaluating 12 behavioral domains with prior use in TBI. NPI-Aggression domain (NPI-A) captures emotional reactivity, resistance to activities, obstinate conduct, lack of cooperation, verbal outbursts, profanity, and physical aggression. Assessment involves identifying if these behaviors are present and then scoring the most concerning manifestation on severity (1=mild to 3=severe) and frequency (1-4 scale, higher=greater occurrence). Domain totals (0-12 range) represent the product of severity and frequency ratings for the predominant symptom.

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Neuropsychiatric Inventory-Aggression Domain - Observer-rated Proportion Improved ≥ 3 Points Baseline to Day-91
28 Participants
27 Participants

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

Neuropsychiatric Inventory (NPI) is a 40-item instrument evaluating 12 behavioral domains with prior use in TBI. NPI-Irritability domain (NPI-I) encompasses temper outbursts, mood fluctuations, abrupt anger, impatience, irritable disposition, and argumentative behavior. Assessment involves identifying if these behaviors are present and then scoring the most concerning manifestation on severity, frequency, and distress. The NPI-I Distress quantifies the emotional burden experienced by the rater regarding the most troublesome behavior using a 6-point rating system 0 to 5 (lower scores=lower distress).

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Neuropsychiatric Inventory-Distress Irritability Domain - Observer-rated
2.0 Scores on a scale
Standard Error 0.2
1.7 Scores on a scale
Standard Error 0.2

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

Neuropsychiatric Inventory (NPI) is a 40-item instrument evaluating 12 behavioral domains with prior use in TBI. NPI-Aggression domain (NPI-A) captures emotional reactivity, resistance to activities, obstinate conduct, lack of cooperation, verbal outbursts, profanity, and physical aggression. Assessment involves identifying if these behaviors are present and then scoring the most concerning manifestation on severity (1=mild to 3=severe) and frequency (1-4 scale, higher=greater occurrence). Domain totals (0-12 range) represent the product of severity and frequency ratings for the predominant symptom. The NPI-A Distress quantifies the emotional burden experienced by the rater regarding the most troublesome behavior using a 6-point rating system 0 - 5 (lower scores=lower distress).

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Neuropsychiatric Inventory-Distress Aggression Domain - Observer Rated
1.5 Scores on a scale
Standard Error 0.2
1.3 Scores on a scale
Standard Error 0.2

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

A self-report measure of overall neurobehavioral function. St Andrew's-Swansea Neurobehavioural Outcome Scale (SASNOS) is a 49-item observer-rated measure of neurobehavioral dysfunction in acquired brain injury. This study utilized the 15-item aggression subscale (overt aggression, irritability, and provocative behavior). The scale uses a 7-point Likert scale ("never" to "always") for items, and raw total scores are converted into standardized T-scores (M=50),(SD=10). Higher score reflects less aggression with a clinically relevant range usually extending from below (30) (indicating significant disability/high aggression) to (70) or higher (fewer symptoms).

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
St. Andrews-Swansea Neurobehavioural Outcome Scale - Observer-rated
51.7 units on a scale
Standard Error 1.3
53.1 units on a scale
Standard Error 1.2

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

A self-report measure of overall change. Global Impression of Change (GIC) employs a 5-point Likert scale whereby observers rate perceived changes in the participant from significant improvement to substantial deterioration. High score reflects worsening. Score ranges 1 to 5: 1-much improved, 2-mildly improved, 3-unchanged, 4-mildly worsened, 5-much worsened.

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Global Impressions of Change - Observer-rated
2.8 score on a scale
Standard Deviation 1.3
2.7 score on a scale
Standard Deviation 0.9

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

A measure of depression that maps on to Diagnostic and Statistical Manual (DSM) criteria for depression. Personal Health Questionnaire-9 (PHQ-9) is a 9-item self-report depression screening based on DSM-V criteria with validity and reliability in TBI populations. Higher scores indicate greater presence of recent depression symptoms. PHQ-9 has a total score range of 0 to 27, based on 9 items scored from 0 ("not at all") to 3 ("nearly every day"). It is a validated tool for assessing depression severity in various populations, including those with traumatic brain injury.

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Personal Health Questionnaire - Participant-rated
5.3 score on a scale
Standard Deviation 0.6
5.2 score on a scale
Standard Deviation 0.6

SECONDARY outcome

Timeframe: 91 day

Population: 3 participants withdrew

A self-report measure of anxiety. Generalized Anxiety Disorder-7 (GAD-7) is a 7-item self-report questionnaire assessing generalized anxiety disorder symptoms based on DSM-V criteria. Total score ranges from 0 to 21, where higher scores indicate greater severity of anxiety. Scores are categorized as: 0-4 (Minimal), 5-9 (Mild), 10-14 (Moderate), and 15-21 (Severe). A score of 10 or higher is commonly used as the cutoff for clinical screening.

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Generalized Anxiety Disorder - Participant-rated
6.0 score on a scale
Standard Error 0.7
4.8 score on a scale
Standard Error 0.7

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

A self-report measure of overall impact of anger on quality of life. TBI-Quality of Life (TBI-QOL) Anger is a 10-item measure of the continuum of anger in TBI populations that is calibrated with the Patient Reporter Outcome Measurement Information System (PROMIS) scales. The measure assesses self-reported frequency and intensity of anger symptoms-including irritability, frustration, and outward aggression-in individuals with traumatic brain injuries. A T-score metric is used, typically ranging from roughly 30 to 80+, where a mean of 50 and a standard deviation (SD) of 10 represent the general population. Higher scores indicate more severe anger.

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Traumatic Brain Injury-Quality of Life Anger - Participant-rated
50.8 T-score
Standard Error 1.4
51.0 T-score
Standard Error 1.4

SECONDARY outcome

Timeframe: Day 91

Population: 3 participants withdrew

Clinician rating of overall change. The Clinical Global Impressions (CGI) scale is a 3-item, 7-point observer-rated instrument used in psychiatry to assess treatment response. It measures severity of illness (1-7), global improvement (1-7), and the efficacy index (0-4) or specific combinations of therapeutic/side effects). Lower scores generally indicate better outcomes (e.g., 1="Very much improved"). CGI-Improvement (CGI-I) (1-7): Assesses change from baseline, with 1 indicating "very much improved" and 7 indicating "very much worse".

Outcome measures

Outcome measures
Measure
Buspirone Treatment
n=38 Participants
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 Participants
placebo tablets as prescribed
Clinical Global Impressions -- Global Improvement -- Clinician Rated.
2.4 score on a scale
Standard Deviation 1.4
2.1 score on a scale
Standard Deviation 1.1

Adverse Events

Buspirone Treatment

Serious events: 0 serious events
Other events: 24 other events
Deaths: 0 deaths

Buspirone Placebo

Serious events: 1 serious events
Other events: 22 other events
Deaths: 0 deaths

Serious adverse events

Serious adverse events
Measure
Buspirone Treatment
n=41 participants at risk
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 participants at risk
placebo tablets as prescribed
Nervous system disorders
Seizure
0.00%
0/41 • From enrollment until end of day 91 follow up visit
2.5%
1/40 • Number of events 1 • From enrollment until end of day 91 follow up visit

Other adverse events

Other adverse events
Measure
Buspirone Treatment
n=41 participants at risk
starting at 15 mg/day and ending at 60 mg/day as prescribed
Buspirone Placebo
n=40 participants at risk
placebo tablets as prescribed
Ear and labyrinth disorders
Ear and labyrinth disorders
2.4%
1/41 • From enrollment until end of day 91 follow up visit
2.5%
1/40 • From enrollment until end of day 91 follow up visit
Eye disorders
Eye disorders
2.4%
1/41 • From enrollment until end of day 91 follow up visit
0.00%
0/40 • From enrollment until end of day 91 follow up visit
Gastrointestinal disorders
Gastrointestinal disorders
12.2%
5/41 • From enrollment until end of day 91 follow up visit
15.0%
6/40 • From enrollment until end of day 91 follow up visit
General disorders
General disorders and administration conditions
9.8%
4/41 • From enrollment until end of day 91 follow up visit
17.5%
7/40 • From enrollment until end of day 91 follow up visit
Immune system disorders
Immune system disorders
0.00%
0/41 • From enrollment until end of day 91 follow up visit
2.5%
1/40 • From enrollment until end of day 91 follow up visit
Infections and infestations
Infections
2.4%
1/41 • From enrollment until end of day 91 follow up visit
12.5%
5/40 • From enrollment until end of day 91 follow up visit
Injury, poisoning and procedural complications
Injury, poisoning, and procedures complications
0.00%
0/41 • From enrollment until end of day 91 follow up visit
5.0%
2/40 • From enrollment until end of day 91 follow up visit
Musculoskeletal and connective tissue disorders
Musculoskeletal
0.00%
0/41 • From enrollment until end of day 91 follow up visit
2.5%
1/40 • From enrollment until end of day 91 follow up visit
Nervous system disorders
Neurologic
19.5%
8/41 • From enrollment until end of day 91 follow up visit
15.0%
6/40 • From enrollment until end of day 91 follow up visit
Psychiatric disorders
Psychiatric
14.6%
6/41 • From enrollment until end of day 91 follow up visit
25.0%
10/40 • From enrollment until end of day 91 follow up visit
Renal and urinary disorders
Urinary Tract
2.4%
1/41 • From enrollment until end of day 91 follow up visit
0.00%
0/40 • From enrollment until end of day 91 follow up visit
Respiratory, thoracic and mediastinal disorders
Pulmonary
2.4%
1/41 • From enrollment until end of day 91 follow up visit
12.5%
5/40 • From enrollment until end of day 91 follow up visit
Skin and subcutaneous tissue disorders
Dermatologic
4.9%
2/41 • From enrollment until end of day 91 follow up visit
2.5%
1/40 • From enrollment until end of day 91 follow up visit
Vascular disorders
Vascular
2.4%
1/41 • From enrollment until end of day 91 follow up visit
0.00%
0/40 • From enrollment until end of day 91 follow up visit

Additional Information

Flora Hammond

Indiana University School of Medicine

Phone: 317-329-2000

Results disclosure agreements

  • Principal investigator is a sponsor employee
  • Publication restrictions are in place