Intravenous Sub-anesthetic Ketamine Treatment in Treatment-Resistant Depression
Phase: PHASE2
Conditions: Treatment-resistant Depression
Sponsor: VA Office of Research and Development

 
STUDY PROTOCOL 
RANDOMIZED, DOUBLE-BLIND, PLACEBO CONTROL STUDY OF A SINGLE VERSUS 
REPEATED INTRAVENOUS SUB-ANESTHETIC KETAMINE TREATMENT IN 
REFRACTORY DEPRESSION 
NCT02360280 
LAST IRB APPROVED VERSION: 06/05/2018 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

BACKGROUND  
Prevalence and Impact of Treatment-Resistant Depression 
Treatment-resistant depression (TRD) has been broadly defined as a major depressive disorder 
that fails to remit despite an adequate course of antidepressant medication treatment (Fava 
2003). Among patients with major depressive disorder (MDD), those with TRD have greater 
risk of suicide (Papakostas et al. 2003), earlier relapse if remission is achieved (Fekadu et al. 
2009) and incur the highest direct and indirect medical costs compared to treatment responders 
(Russell et al. 2004). Considering various definitions of TRD, the estimated prevalence ranges 
from 10% to 60% of all depressed patients (Fava 2003) (Rush et al. 2006).  
 
A case-control study from the Veterans Health Administration and the National Death Index 
estimated that among depressed veterans who committed suicide between 2003-2006, 11.6% had 
TRD compared to 6.4% among controls (Pfeiffer et al. 2013). In the same study, the risk of 
suicide was 73% higher among veterans with MDD compared to veterans with other diagnosis 
(Pfeiffer et al. 2013). Considering that the prevalence of MDD in the VA Healthcare System 
(VAHCS) is almost twice as high as in the general United States population (12% vs.7%) (Blow 
FC, Owen RE, Valenstein M, Austin K, Khanjua K, McCarthy JF. ), and the high rates of 
hospitalization, suicide, and comorbidity among depressed VA patients (Blow FC, Owen RE, 
Valenstein M, Austin K, Khanjua K, McCarthy JF. ); (Valenstein et al. 2009), the prevalence of 
veterans with TRD should be at least similar if not higher than more broadly representative 
depressed populations in the community. The prevalence and severity of depression, including 
TRD, within veterans suggests a need for wide dissemination of maximally effective treatments 
for depression throughout the VA system. Unfortunately, some of the most effective treatments 
for depression, such as ECT, are not well distributed across VA medical centers (Pfeiffer et al. 
2011). A recent report by the HSR&D’s Evidence-based Synthesis Program found a lack of 
evidence to support favoring psychotherapy over antidepressant medication for mid-life adults 
with TRD (Trivedi et al. 2009).Thus, there is a pressing need to investigate new 
interventions in the treatment of TRD.  
 
To enhance drug development efforts for depression, study of interventions that are radically 
different from current agents are now being utilized. The cutting-edge discovery of ketamine’s 
rapid and efficacious effect in TRD opens new avenues to examine the potential role of 
glutamatergic agents. However, a single ketamine infusion appears insufficient to maintain 
response as the duration of antidepressant effects appeared to be approximately 1 week in some 
patients. To improve antidepressant efficacy, the use of repeated intravenous (IV) ketamine 
infusions is beginning to be explored. Rasmussen et al. (Rasmussen et al. 2013) had a response 
rate of 80% using up to four infusions. Murrough et al. (Murrough et al. 2013b) reported a 
response of 71% at the end of six infusions. In our pilot study among veterans with TRD 
(Shiroma et al. 2014), 92% responded after completion of six infusions, and 45% maintained 
response for at least 4 weeks after the last infusion. The strategy of multiple infusions to 
increase efficacy and sustain antidepressant effects has not yet been systematically evaluated in 
an RCT. 
 
SPECIFIC AIMS 

The overall objective of this proposal is to determine the efficacy of a single vs. multiple sub-
anesthetic IV ketamine infusions for patients with TRD. We plan to conduct a randomized 
controlled trial (RCT) comparing a single ketamine infusion preceded by 5 midazolam infusions 
vs. six ketamine infusions. Midazolam, a GABAA agonist without action on NMDA receptors, 
will serve as an active placebo. We plan to test our central hypothesis by pursuing the following 
specific aims: 
Primary Aim 1: To determine the efficacy of a single versus six IV ketamine infusions among 
patients with TRD over a 12-day treatment phase. H1: Patients who complete six ketamine 
infusions will have greater reduction of depression severity than those who received a single 
ketamine infusion (preceded by 5 midazolam infusions).  
Aim 2: To determine the durability of antidepressant effect after completion of a single versus 
six ketamine infusions. H2: Patients treated with six ketamine infusions will sustain 
antidepressant effect for longer period than those who received a single ketamine infusion 
(preceded by 5 midazolam infusions) over a 6-month follow-up period.  
Exploratory Aim 3: To assess the time course of change in depressive symptoms among patients 
who received six IV ketamine infusions over a 12-days treatment. 
Exploratory Aim 4: To study predictors of treatment response that focus on functional brain 
imaging (resting state and task functional MRI) , intracellular mediators of antidepressant 
effects and cognitive function. 
 
   
RESEARCH DESIGN AND METHODS 
Design Overview 
The proposed study is a one-center, interventional, efficacy study designed to determine 
antidepressant outcomes (response, remission and relapse) 
of serial ketamine infusions compared to a single ketamine 
infusion among patients with TRD (Figure 1). Given our 
pilot findings, we have hypothesized that six infusions will 
be superior to a single infusion of ketamine in both 
decreasing severity of depressive symptoms and 
maintaining response. Participants will be male and female 
patients (18 to 75 years old) of any era or military 
background who suffer from TRD. Potential participants 
will be recruited from Mental Health clinics in the 
MVAHCS and screened for eligibility using a two stage 
process (phone/chart review, followed by interview). Those 
who meet eligibility criteria will complete baseline 
assessments 1-2 weeks prior to starting treatment. We 
estimate that 56 participants will be randomly assigned to 
one of two parallel treatment conditions: 1) a single 
ketamine infusion preceded by five midazolam infusions or 2) six ketamine infusions. 
Midazolam, a short-acting benzodiazepine and anesthetic agent, may serve as a control 

condition given pharmacokinetic characteristics similar to those of ketamine, fast onset of 
action, and short elimination half-life (Kanto 1985). Midazolam would also mimic ketamine in 
terms of the time course of dissociative and nonspecific behavioral effects (e.g., sedation, 
disorientation). In fact, the use of IV midazolam at 0.045 mg/kg was recently used as active 
placebo to enhance masking intention (Murrough et al. 2013a). Each intervention will be 
administered over a 12-day infusion-phase on a Monday-Wednesday-Friday schedule followed 
by 6-month follow-up. We estimate that out of 56 patients, 42 will complete treatment phase 
and will be considered for primary analysis. Independent evaluation of depressive symptom 
severity and potential covariates of antidepressant effect will be ascertained at baseline, at 
several time points during infusion period, and at follow-up. 
 
Subject Recruitment and Selection  
Participants will be recruited from patients receiving mental health treatment in the MVAHCS 
and in the community. Referrals will occur from  clinicians and clinics, and responses from 
posted fliers and study pamphlets. Potential participants will be provided with information 
about the study and screened through medical records, chart review, and by telephone to 
determine whether they meet basic inclusion/exclusion criteria. Those who qualify will be 
scheduled for a more rigorous assessment (see further details below).  
 
Eligibility Criteria. The following eligibility criteria that identify a broad array of participants 
with TRD.  
 
Inclusion Criteria:  
1. Male or female patients aged 18 to 75 years.  
2. Have a telephone in their home and able to hear telephone conversations. 
3. Must meet current DSM-IV criteria for MDD, single or recurrent, without psychotic features 
confirmed by depression subset of the Structured Clinical Interview-Clinical Trial for DSM-
IV (SCID) (Lobbestael, Leurgans & Arntz 2011).  
4. Have score ≥32 on the Inventory of Depressive Symptomatology—Clinician Rated (IDS-C30) 
(Rush et al. 1996) for severity of major depressive episode (MDE) at screening. 
5. Current major depressive episode resistant to treatment defined as failure to achieve 
improvement from at least 2 antidepressant trials of different pharmacological classes. 
Systematic evaluation of previous antidepressant trials will be assessed by the 
Antidepressant Treatment History Form (ATHF) (Sackeim 2001).  
6. If applicable, current antidepressant dosages including augmenting agents and/or frequency 
and duration of psychotherapy sessions must remain stable for at least 6 weeks prior to 
beginning of the study.  
 
Exclusion Criteria: 
1. Inability to speak English. 
2. Inability or unwillingness to provide written informed consent.  
3. Moderate/severe cognitive impairment by Mini Mental State Examination (MMSE) 
(Folstein, Folstein & McHugh 1975) scores ≤27.  
4. Current or lifetime DSM-V criteria for post-traumatic stress disorder (PTSD), acute stress 
disorder, psychosis-related disorder, bipolar disorder I or II disorder, substance-induced 
mood disorder, any mood disorder due to a general medical condition or any Axis I disorder 
other than MDD as the primary presenting problem. 

5. History of moderate or severe traumatic brain injury, Parkinson's disease, dementia of any 
type, multiple sclerosis, seizures or other CNS related disorders.  
6. History of comorbid substance disorder within 6 months of assessment plus positive urine 
toxicology screen test during baseline assessments. 
7. Clinically unstable medical illness that could compromise the patient's ability to tolerate or 
likely interfere with the study procedures (e.g., history of or current myocardial ischemia or 
arrhythmias, congestive heart failure, severe pulmonary, renal, or hepatic disease, 
uncontrolled hypertension).  
8. Current or within less than 14 days use of barbiturates or monoamine oxidase inhibitors 
(MAOi).  
9. For women: pregnancy (confirmed by lab test), initiation of female hormonal treatments 
within 3 months of screening, or inability/ unwillingness to use a medically accepted 
contraceptive method during the study. 
10. Imminent risk of suicidal/homicidal ideation and/or behavior with intent and/or plan. 
 
 
Pre-Screening. In order to reduce subject burden, we will obtain a waiver of HIPAA 
authorization to allow potential subjects to be pre-screened by chart review and in person or by 
telephone prior to scheduling an Eligibility and Baseline Assessment visit. Potential participants 
will be provided with information about the study and asked a series of questions to determine 
if they meet basic inclusion/exclusion criteria (e.g., indicators of current MDD). They will be 
informed that the treatment involves multiple infusions of sedatives at subanesthetic doses. 
Those interested will be scheduled for an Eligibility and Baseline Assessment. 
 
Informed Consent Procedures 
Before Eligibility and Baseline Assessment, voluntary informed consent will be obtained in 
accordance with local IRB approvals. At the consent session, all assessments, and information 
on treatment will be explained. Subject comprehension of information will be assessed by the 
Modified Dysken Screening Tool,  an instrument commonly used at MVAHCS to determine 
decision-making capacity of a potential research subject to provide informed consent to 
participate in research. Willingness to participate in assessments and random assignment to 1 of 
2 treatments will be confirmed and information about confidentiality and study payments will 
be provided. 
 
Assessment Procedures. Assessments will take place in two contexts:1) at baseline and 
throughout treatment and follow-up, and 2) during each infusion. Baseline and outcome 
assessments will take place in the initial contact with the participant and over the phone, while 
infusion assessments will take place as part of the infusion procedures. These assessments are 
summarized in Table 1 and Table 2, respectively. Clinical interviews will be conducted by 
trained independent evaluators (IEs) who are blind to participant treatment condition. Subject 
compensation will also be provided to increase participant retention and reduce missed 
assessments (see further details below). 
 
Eligibility and Baseline Assessment. The Eligibility and Baseline Assessment will be 
accomplished during 1-2 visits over a 7-14 day period prior to starting treatment. It will take a 
total of 4 hours. TRD will be defined by the ATHF (Sackeim 2001) based on information from 
patient’s report, and from past treatment providers, pharmacies, and medical records. IEs will 

administer the Inventory of Depressive Symptomatology-Clinician Version (IDS-C30) (Rush et 
al. 1996) to determine the severity of current depressive episode. The Structured Clinical 
Interview-Clinical Trial version for DSM-IV (SCID-CT) (Lobbestael, Leurgans & Arntz 2011) 
will confirm the diagnosis of MDD and the absence of exclusionary diagnoses. Lack of 
moderate/severe cognitive impairment will be ascertained with an MMSE (Folstein, Folstein & 
McHugh 1975) score ≥ 28. Imminent risk of suicide/homicide ideation and/or plan will be 
assessed by interview. The Columbia-Suicide Severity Rating Scale (C-SSRS) Screening Version 
– Since Last Visit will be added to complement suicide exclusion criterion (affirmative response 
to questions 3, 4, 5 or 6). Perceived effectiveness with treatment received (CEQ) will also be 
assessed.  
 
Evaluation of exclusionary criteria involving unstable medical illnesses will be based on medical 
record review by Principal Investigator in consultation with study anesthesiologist, Dr. Wels. A 
urine pregnancy and drug screen will be obtained to ensure no one is pregnant and to document 
possible illicit substance use. Research staff will also assess clinical impression of illness severity 
(CGI) (Guy 1976) and quality of life (WHOQOL-BREF) (Skevington et al. 2004). In addition, 
patients will provide information from at least two competent adults that will serve as 
alternative emergency contact during the study (see Appendix 1). In this same line of thought, a 
hand-out describing steps to follow in case of decompensation including VA contact 
information will be provided prior to study onset (Appendix 2).  
 
Treatment Assessment. The research staff will ascertain for measures of depressive symptoms 
severity, potential covariates of antidepressant effect, and side effects at Eligibility and Baseline 
Assessment beginning and at Day 2, 4, 6, 9, 11, and 13 during infusion phase. We will assess levels 
of anxiety (BAI) and pain intensity (NSR for pain) as covariates because 1) anxiety might 
negatively impact antidepressant response (Steffens, McQuoid 2005); 2) the analgesic effect of 
ketamine used in this study may indirectly result in improvement of depressive symptoms. To 
reduce subject burden, and decrease missing data, repeated measures (MADRS, BAI, C-
SSRS,and NSR for pain) will be conducted via telephone interviews 24-hours post infusion on 
the repeated measure. Prior studies suggested that peak of antidepressant effects to ketamine 
occur 24 hours after administration (Zarate et al. 2006a) (Mathew et al. 2010). The MADRS for 
interviews conducted by telephone is comparable to interviews conducted by face-to-face 
administration (Kobak et al. 2008); as self-reported tools, the BAI and NRS can be reliably used 
in a similar way. Psychotogenic effects will be measured with the four-item positive symptom 
subscale of the Brief Psychiatric Rating Scale (BPRS+) (Overall 1962) consisting of 
suspiciousness, hallucinations, unusual thought content, and conceptual disorganization; 
dissociative effects and manic symptoms will be measured with the Clinician-Administered 
Dissociative States Scale (CADSS) (Bremner et al. 1998) and Young Mania Rating Scale (YMRS) 
(Young et al. 1978), respectively. Additionally, the patients were regularly questioned during the 
infusions about any dysphoric emotions or altered sensory experiences. We anticipate the 
telephone treatment assessments will take no more than 20 minutes on the phone. 
 
Follow-up Assessment. Following completion of treatment (Week 3), participants will attend 
Post-Treatment Assessment at weekly intervals for the first 4 weeks, at 2-week intervals for the 
next 8 weeks, and at 4-week intervals for the remaining 12 weeks. Psychiatric medication 
changes will be discouraged during follow-up. In the case that the patient relapses (<50% of 
baseline MADRS score at that follow-up visit), follow-up will continue as scheduled with 

subsequent mental care being managed by her clinician to change or add medications if needed. 
Each visit will take about 2 hours. Similar to the baseline assessment session, follow-up 
assessments will involve interview guide for depressive symptom severity (MADRS), suicide 
assessment (C-SSRS), clinical impression of illness severity and improvement (CGI), as well as 
self-reported measures of pain intensity (NRS for pain), level of anxiety (BAI), and  quality of 
life (WHOQOL-BREF).  
Secondary Outcomes.   
 
Neuroimaging: The neural networks involved in ketamine treatment need to be elucidated yet. For 
this purpose, a multi-modal imaging technique will be obtained within one week prior to the 
first infusion and again within one week following the final infusion for a sub-sample of 15 
participants. This portion of the study will remain optional and clearly expressed in the 
informed consent. Additional monetary compensation will be provided for participation. 
Patients will be scanned using 3Tscanner located at the University of Minnesota Center for 
Resonance Research (CMRR-Project #10097). We will obtain a 5 min high-resolution T1-
weighted anatomical image, and a 6 min multi-band resting-state scan comprising 180 
contiguous echo planar imaging (EPI) whole-brain functional volumes (TR = 2000ms; TE = 
30ms; flip angle = 90; 34 contiguous AC-PC aligned axial slices; matrix = 64×64; FOV = 22cm; 
acquisition voxel size = 3.4×3.4×4mm). A 14-min functional MR (fMRI) with same parameters as 
above will be conducted while participants engage in an Emotional Stroop task, where they will 
be asked to evaluate words appearing below happy or sad faces, as ‘positive’ or ‘negative’. This 
task is designed to have 4 different runs, each lasting for 3.5 min and containing 16 words (8 
positive-8 negative) recurring as congruent (e.g. positive word-happy face) and incongruent 
(negative word- happy face).  Once neuroimaging is completed, information about active vs 
placebo arm for those 15 patients will be disclosed from the research pharmacist to study co-
investigator at the CMRR (Dr. Lim). Patients will be identified by an alphanumeric code 
different from that used at the VA. In this sense, we will assure blinding to investigators and 
assessors involved in conducting the clinical trial at VA site. 
 
Peripheral biomarkers: The pathophysiology of antidepressant-resistant depression is 
characterized by dysregulated neural network activity, hypothalamic-pituitary-adrenal axis 
dysfunction, elevated levels of pro-inflammatory cytokines and kynurenines, with consequent 
alterations in neurotransmitter signaling (particularly glutamate) and central metabolic 
disruption. We plan to examine a platform of biomarkers of treatment response that focus on 
major metabolites; white blood cell stimulated protein kinase B (Akt), mTOR, and glycogen 
synthase kinase 3 (GSK3) signaling (intracellular mediators of antidepressant response) and an 
exploratory ketamine response gene expression signature (transcriptomic bioinformatics 
approach). For this purpose, 20cc blood will be drawn for Peripheral Blood Mononuclear Cell 
(PBMC) isolation prior to the first infusion and 2 hours after the fifth infusion.  10cc blood will 
be drawn into a serum tube for serum and buffy coat prior to the first infusion and 2 hours after 
the final infusion. Another 20cc of blood only for Peripheral Blood Mononuclear Cell (PBMC) 
isolation will be drawn by venipuncture as described above at each subsequent follow-up visit 
after infusions are completed. All tubes will be labeled with a study identifier, collection date, 
and time of draw. Analyses will be conducted by Dr. Susannah Tye at Mayo Clinic. Buffy coat 
and serum samples will be flash frozen and stored at -80C. Serum will be stored as 1ml aliquots 
at −80°C. Metabolomics analysis will be performed on serum samples and differential pre- versus 
post-ketamine mRNA and protein levels will be quantified from buffy coat samples. 

Bioinformatics pathway analysis will be used to identify key differences in molecular responses 
to ketamine. These assays will be used to better understand the physiologic mechanisms of 
ketamine response/non-response. 
 
The 20cc heparinized tube of whole blood will be mixed with an equivalent amount of 
phosphate buffered saline (PBS). This mixture will be slowly overlaid onto Ficoll, the 
mononuclear layer recovered, and cells washed with PBS. PBMCs will be isolated from whole 
blood and viably frozen. PBMCs will be cultured and stimulated with insulin and intracellular 
Akt, mTOR, and GSK3 gene and protein levels will be quantified following 0, 5, 15, and 30 
minutes of stimulation. This signaling pathway is implicated in mediating the antidepressant 
response to ketamine. Western blot and rt-PCR techniques will be used to quantify protein and 
gene expression respectively. This assay will be used to identify potential key deficits in this 
signaling pathway that may serve as future biomarker screen of ketamine response/non-
response. Outcomes of each assay will be correlated with patient response profile. All tissue will 
be destroyed upon completion of the study. 
 
Cognitive functions: There are concerns of potential cognitive risks of longer-term ketamine 
treatments. While studies suggest that low-dose ketamine administered over short periods to 
patients with unipolar and bipolar depression does not cause cognitive deficits, in contrast to 
studies of high-dose, long-term administration in frequent ketamine abusers, further evidence 
are needed. On the other hand, slow processing speed at baseline appears to predict respond to 
repeated ketamine treatments in TRD. For this purpose, we will assess cognitive function at 
baseline, within a week after completed infusions, and during subsequent follow-up visits using 
computerized cognitive tasks (www.cogstate.com).  Cognitive subtests will include measures of 
multiple domains such as processing speed, working memory, executive function, and 
associative learning. All tests will be based on playing card formats, with little reliance on or 
assessment of verbal abilities. The battery requires 15 to 20 minutes to be completed. This 
battery was developed for repeat testing with extensive results concerning practice effects. 
 
Quantitative electroencephalography (QEEG): Recent literature indicates that QEEG power in the 
theta and alpha frequency band may identify individuals more likely to respond to TCAs and 
SSRIs within one week of starting an antidepressant medication.  This has led to the 
development of QEEG parameter, the Antidepressant Treatment Response (ATR) index, which 
has been shown to significantly predict remission of depression symptoms at 7 weeks following 
initiation of multifarious SSRIs (Cook 2013; Caudill 2014; Hunter 2011).  Similarly, reduction in 
QEEG theta cordance measured during ketamine infusions was shown to correlate with 
increased positive emotions in healthy volunteers (Horacek 2010).  As such, we propose to 
evaluate frontal quantitative electroencephalogram recordings as a predictive factor of ketamine 
response. For this purpose, we plan to QEEG to be conducted before (t-15), during (t+25 min) 
and after (t+145 min) the first study drug infusion.  Electroencephalogram data will be collected 
in a laptop computer connected to a 4-channel EEG amplifier unit.  Self-prepping electrodes will 
be placed at 4 sites on the forehead and 2 on earlobes.  Each EEG data will be recorded while 
subjects rest during two 6-minute segments with eyes closed, separated by a 2-minute eyes-
open segment (total time of 15 minutes). 

Emotion Processing: A modified emotional Stroop task (EST) will be used to evaluate emotion 
processing.  Subjects will be asked to evaluate words appearing below happy or sad faces, as 
'positive' or 'negative'. This task is designed to have 4 different runs, each lasting for 3.5 min and 
containing 16 words (8 positive-8 negative) recurring as congruent (e.g. positive word-happy 
face) and incongruent (e.g. negative word-happy face).  The task will be administered at 
baseline and then then at post-infusion visits on week 5, 10, 14, 20 and 28 
 
Rumination: Ruminative responding in major depressive disorder is defined as a recurrent, self-
reflective, and uncontrollable focus on depressed mood and its causes and consequences. Higher 
levels of rumination have been found to predict both more severe depressive symptoms in 
depressed individuals and the onset of depressive symptomatology in non-depressed people. We 
will study rumination by using a recently developed task named the Internal Shift Task (IST) 
and the ruminative response scale (RRS). The RRS is a 22-item self-report measure and consists 
of items that describe responses to a depressed mood that are focused on the self-symptoms, or 
consequences of depressed mood. Participants are requested to indicate how often they engage 
in these responses using a four-point Likert scale ranging from 1 (almost never) to 4 (almost 
always). The estimated time to complete the RRS-NL is 8 minutes and will be administered at 
baseline. 
The IST examines cognitive control held in working memory by updating of and mainly 
switching between internal mental representations. The task will be programmed using E-prime 
2.0 software package and run on a laptop computer. The stimuli will be faces taken from the 
Karolinska Directed Emotional Faces. In the IST, faces will be presented at the center of the 
computer screen. Participants will complete an emotion (faces categorized as neutral or angry) 
and gender (faces categorized as male or female) tasks. There will be 12 blocks for both 
conditions with random 10 to 14 trials (or faces) with in each block. The participant’s task will 
keep a silent mental count of the number of faces in each category, presented within a block of 
trials (e.g., participants have to update counters for male and female or neutral and happy faces 
in the gender and emotion condition, respectively). When a face is presented, participants will 
be asked to press the space bar as fast as possible (reaction time measure) to indicate that they 
have updated both internal counters. The next face will appear on the screen after a 200ms 
inter-trial interval. Participants have to report the number of faces of both categories (accuracy 
measure), using the number path of the keyboard, at the end of each block in a fixed order to 
encourage a consistent counting strategy (e.g., report counts for the neutral and then for the 
happy faces in the emotion condition; in the gender condition the order will be male–female). 
The estimated time to complete the IST is 15 minutes.  
 
Impulsivity: The Barratt Impulsivity Scale (BIS-11) is a self-administered 30-item questionnaire 
designed to assess the personality/behavioral construct of impulsivity and takes 10 minutes to 
administer.  The Go/No-Go task (GNG) measures impulse control by manipulating response 
prepotency by presenting a preliminary go or no-go cue before the actual go or no-go target is 
displayed.  The Go/No-Go task presents 250 trials and requires 10 minutes to complete. The 

Balloon Analogue Risk Tasks (BART) is a computer based measure to assess risk taking.  In each 
of 30 trials, a cartoon image of a balloon appears.  Participants click a button to increase the size 
of the balloon.  Each time the balloon is pumped, the participant earns money.  However, the 
balloon, if pumped excessively, will burst, and all the money for that trial is forfeited.  The size at 
which the balloon will burst varies across trials and is not specified to participants.  The average 
number of clicks represents a measure of propensity to accept risks.  This task takes 10 minutes 
to complete. All three impulsivity tasks will be administered at baseline and then at post-
infusion visits on week 5, 10, 14, 20 and 28 
 
 
Assessment Schedules and Measures 
Table 1 illustrates the schedule of assessments over the course of the study including measure of 
depression symptom severity, DSM-IV MDD and other diagnoses, secondary outcomes, and 
perception of treatment. 
Table 1.  General Assessment Schedule  
Construct 
Measure 
Eligibility and 
Baseline 
Assessment 
Repeated Treatment 
Assessments 
Repeated Follow-Up 
Assessment 
 
 
1-2 weeks before 
start of treatment 
Day 2 to 13 
Weekly for 4 weeks, 
biweekly for 8 weeks and 
monthly for 3 months 
Primary Outcome Measure 
Depressive Symptoms 
MADRS 
 
X 
X 
Interview Based Assessments 
Decision-making capacity 
Modified Dysken 
Screening Tool 
X 
 
 
TRD Diagnosis 
ATHF 
X 
 
 
MDD Diagnosis and rule-out 
other diagnosis 
SCID-CT 
X 
 
 
Severity of current MDE 
(IDS-C30) 
X 
 
 
Rule-out moderate/severe 
cognitive impairment 
MMSE 
X 
 
 
Side Effects and Secondary Outcome  Measures 
Brain imaging 
 
X 
X 
 
Peripheral biomarker  
 
 
X 
X 
Cognitive assessment 
 
X 
 
X 
Emotion Stroop Task (EST) 
 
X 
 
X 
Rumination (IST and  RRS-
NL) 
 
X 
 
X 
QEEG 
 
X 
X* 
 
Impulsivity (BIS-11,GNG, 
Bart) 
 
X 
 
X 
Side Effects (dissociative, 
psychotogenic, and manic 
symptoms) 
CADDS, BPRS+, 
YMRS 
 
X 
 
Suicide Risk 
C-SSRS 
X 
X 
X 
Anxiety Symptoms 
BAI 
 
X 
X 

Pain Intensity 
NRS 
 
X 
X 
Recovery from study drug 
infusion 
mAldrete 
 
X 
 
Quality of Life 
WHOQOL-BREF 
X 
 
X 
Global Rating of Illness 
Severity and Improvement 
CGI 
X 
 
X 
Perceptions of Treatment Measure 
Perceptions of Treatment 
CEQ 
X 
 
 
*QEEG will be conducted before (t-15), during (t+25 min) and after (t+145 min) the first study 
drug infusion and then 25 minutes during infusion and at 145 min post-infusion.  
 
Randomization Procedures 
Our planned enrollment includes 28 patients in each treatment condition, for a total of 56 
patients (see Sample Size Determination below). Participants will be randomly assigned to six 
ketamine infusions or single ketamine infusion preceded by 5 midazolam infusions. 
Randomization will be conducted using SAS PROC PLAN. Group assignments for each 
participant will be concealed in sequentially numbered, sealed, opaque envelopes will be 
provided to the study staff by the research pharmacist. 
  
Treatment Conditions 
Over the course of the study, infusions in both treatment conditions will be administered 
individually in a private room located in 3E Unit. Baseline assessments and post-infusions 
follow-up measures will occur at the Mental Health Outpatient. The procedures for both 
treatment conditions are similar and described as follows:  
 
Procedures during infusion. Table 2 describes the schedule of assessments on the day of 
infusion. Patients will arrive in the morning or afternoon after fasting for 8 hours. An indwelling 
catheter will be placed in the non-dominant arm for medication administration. Digital pulse 
oxymetry, respiratory rate, pulse rate, and blood pressure will be recorded every 10 min for 1 
hour beginning 10 min before infusion. Based on the dose, rate of infusion, and endpoint/purpose 
of the study, the infusions do not fall into the category of “moderate sedation” and therefore no 
cardiac monitoring will be required at our institution. Subjects will then receive IV infusion of 
either 0.5 mg/Kg of ketamine hydrochloride solution or midazolam 0.045 mg/kg over 40 
minutes. Only study MDs (Dr. Shiroma, Dr. Wels or Dr. Albott) or study nurse (Debra Condon 
RN), will administer study medications, namely, programming infusion pumps and initiating 
intervention. The dose of ketamine will be calculated by ideal body weight based on sex, age, 
height, and body frame in the Metropolitan Life Insurance tables. Evaluation procedures include 
rating scales (MADRS, BAI, NRS, CADDS, BPRS+, YMRS, and CGI) will be obtained before 
infusion. Potential side effects related to ketamine (CADDS, YMRS, and BPRS+) will be 
measured again immediately upon completion of each infusion and during post-ketamine 
monitoring period. Guidelines established for clinically significant changes in vital signs and 
mental status during the ketamine infusions will be as follows: systolic blood pressure (BP) >161 
or <89, diastolic BP >110; heart rate <40 or >130 beats/min; respiratory rate <10 or >30 per minute; 
pulse oxymetry <90%; severe hallucinations, confusion, delusions, irrational behavior, or 
agitation. Research personnel will record vital signs prior, during and after infusion. One of MDs 
or RN will be present throughout the infusion plus study anesthesiologist (Dr. Wels) will be 
available to be reached during infusions if necessary. Medications such as labetalol, ondansetron, 

and flumenazil as well as a crash cart will be available to manage unanticipated side effects. The 
infusion will be discontinued if adverse events do not respond to interventions. After end of 
infusion, MD or RN will assure that patient’s physical and mental status are stable and 
appropriate continue with monitoring of vital signs and completion of rating scales. All subjects 
will be monitored at least for 2 hours post infusion. Before leaving the infusion unit, subjects 
will be assessed by MD or RN to demonstrate that all clinically significant side effects are 
resolved by obtaining a score≥9 in the modified Aldrete scoring system (Aldrete 1995). Written 
instructions about rare but serious side effects and several measures to improve recovery at 
home will be provided at discharge. The standard operating procedure (SOP) in Appendix 3 
include a detailed plan for administration of the study drug and monitoring of participants 
including a description of the qualifications of the personnel responsible for each of these tasks. 
 
Table 2. Assessment Schedule on Infusion Day 
*Hemodynamic measures will be monitored every 10 minutes for one hour, beginning 10 minutes prior to the infusion. 
Compensation for assessment sessions 
Participants will be compensated for completing the assessment sessions throughout the study. 
Assessment sessions involve individual clinical interviews, self-report, and semi-structured 
questionnaires. Compensation for assessment sessions will be delivered according to the 
following schedule: $50 for Eligibility Screen and Baseline (1-2 weeks prior to starting 
treatment, approximately 4 hours), $25 for each Treatment Assessment (a total of 6 over 12 days, 
approximately 3 hours each), $50 when Treatment is complete, and $30 for each Follow-up 
Assessment (total of 11 over 6 months following end of treatment, approximately 2 hours each) 
for a total of $580. Participants who prematurely withdraw from study assessments will not be 
compensated for assessment sessions that have not yet taken place. For the brain imaging part of 
the study, an additional $50 will be given after each scan (total of $100). 
 
Test of Blinding. 
The success of blinding will be tested on a 5-point scale at the end of the infusion period using a 
2 × 5 format (LaRosa, 1994). Subjects will be asked to rate the extent of certainty about their 
 
Measure 
 
Baseline (t0)-60 
min 
t0+40 min 
t0+100 min 
t0+160 min 
t0+24 
hrs. 
Primary Outcome Measure 
Depressive Symptoms 
MADRS 
 
X 
 
 
 
X 
Secondary Outcome Measures 
 
 
 
Anxiety symptoms 
BAI 
 
X 
 
 
 
X 
Pain intensity 
NRS 
 
X 
 
 
 
X 
Suicide Risk 
C-SSRS 
 
X 
 
 
 
X 
Hemodynamic Measures 
BP,pulse,RR,SatO2 
 
 
X* 
X 
X 
X 
 
Side Effects Measures 
Dissociative Symptoms 
CADDS 
 
X 
X 
X 
X 
 
Psychotogenic Symptoms 
BPRS+ 
 
X 
X 
X 
X 
 
Manic Symptoms 
YMRS 
 
X 
X 
X 
X 
 
Recovery from study drug 
infusion 
mAldrete 
 
 
 
 
X 
 

treatment on the following scale: 1) strongly believe the treatment is active, 2) somewhat believe 
the treatment is active, 3) somewhat believe the treatment is placebo, 4) strongly believe the 
treatment is placebo and 5) do not know. In addition, subjects who initially answered ‘do not 
know’ will be re-asked to choose one treatment (in 2×2 format) providing validation of the ‘do 
not know’ data. 
 
Table 3. Study Timeline 
 
Year 1 
Year 2 
Year 3 
Year 4 
1 
2 
3 
4 
1 
2 
3 
4 
1 
2 
3 
4 
1 
2 
3 
4 
Start-up 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Enrollment 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Interventions  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Outcome assessments 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Data entry/cleaning 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Statistical analysis 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Report writing 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Potential Problems & Alternative Strategies. 1) Recruitment could be slower than anticipated. Based 
on our pilot recruitment, and the fact that over 400 veterans meet criteria for TRD based on 
administrative data, we are very confident of our ability to meet recruitment goals.  However, we 
have the option of expanding recruitment to outpatient satellite clinics (CBOCs) and non-VA 
community clinics if needed to increase enrollment rates. 2) Severe attrition and missing data. 
Based on our sample size calculation including conservative attrition rate of 30%, the study is 
adequately powered for our study aims. In our own sample, out of 14 subjects, only 2 dropped 
out, consisting with tolerability and safety from previous reports (Murrough et al. 2013b) 
(Rasmussen et al. 2013). If risk of dropping out due to assessment burden occurs, subjects will 
have the option of completing a minimum core assessment comprising primary outcome 
measures. A DSMB will be assembled to ensure safety. Missing data would be handled as 
described in Data Analysis. 3) Patients may be lost to follow-up. We would initiate outreach 
procedures such as letters and phone calls. If there is concern about suicide risk as an 
outpatient, established clinical procedures that includes safety check by police will be 
performed. 
 
 
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