Working...
ClinicalTrials.gov
ClinicalTrials.gov Menu

The Effects of Cannabis Use in People With Schizophrenia on Clinical, Neuropsychological and Physiological Phenotypes

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Read our disclaimer for details.
ClinicalTrials.gov Identifier: NCT01832766
Recruitment Status : Terminated (Unable to find subjects with schizophrenia that were using only cannabis)
First Posted : April 16, 2013
Results First Posted : September 21, 2015
Last Update Posted : September 21, 2015
Sponsor:
Collaborator:
National Alliance for Research on Schizophrenia and Depression
Information provided by (Responsible Party):
University of Colorado, Denver

Tracking Information
First Submitted Date  ICMJE March 25, 2013
First Posted Date  ICMJE April 16, 2013
Results First Submitted Date  ICMJE June 30, 2014
Results First Posted Date  ICMJE September 21, 2015
Last Update Posted Date September 21, 2015
Study Start Date  ICMJE June 2005
Actual Primary Completion Date May 2010   (Final data collection date for primary outcome measure)
Current Primary Outcome Measures  ICMJE
 (submitted: August 18, 2015)
P50 Auditory Evoked Potential [ Time Frame: 2 hours after drug administration ]
electrophysiological measure of ability to filter extraneous stimuli measured as the amplitude of the evoked response to the second auditory stimulus divided by the amplitude of the evoked response to the first auditory stimulus in mV.
Original Primary Outcome Measures  ICMJE
 (submitted: April 11, 2013)
P50 Auditory Evoked Potential [ Time Frame: 2 hours after drug administration ]
electrophysiological measure of ability to filter extraneous stimuli
Change History Complete list of historical versions of study NCT01832766 on ClinicalTrials.gov Archive Site
Current Secondary Outcome Measures  ICMJE
 (submitted: August 18, 2015)
California Verbal Learning Test Change at 2 Hours From Baseline [ Time Frame: 2 hours after drug administration ]
ability to remember a list of words given 5 trials. Number of words remembered is normalized to a schizophrenia population and average scores are calculated with age correction. The normal T-score is 50 and scores greater than 50 correspond with greater ability to remember words as compared to a schizophrenia population norm.
Original Secondary Outcome Measures  ICMJE
 (submitted: April 11, 2013)
California Verbal Learning Test [ Time Frame: 2 hours after drug administration ]
ability to remember al list of words
Current Other Pre-specified Outcome Measures
 (submitted: August 18, 2015)
Brief Psychiatric Rating Scale Change From Baseline at 1 Hour [ Time Frame: at 1 hour after drug administration ]
Measures psychiatric symptoms. Each item is scored from 1-7. Positive symptoms are calculated from sum of scores on hallucinatory behavior, unusual thought content and conceptual disorganization. Thus, the range of Total Positive Symptoms can be from a score of 3-21 .The higher the score, the more severe the symptom. Negative symptoms have been calculated from sum of blunted affect, emotional withdrawal and motor retardation. The range of Total Negative Symptoms can be from a score of 3-21. The higher the score, the more severe the symptoms. As this is a difference from baseline, there can be either negative or positive results as the subjects can either be better than baseline (positive score) or worse than baseline (negative score).
Original Other Pre-specified Outcome Measures
 (submitted: April 11, 2013)
Brief Psychiatric Rating Scale [ Time Frame: at 1 hour and 8 hours after drug administration ]
Measures psychiatric symptoms and can be subdivided in to positive and negative subscales
 
Descriptive Information
Brief Title  ICMJE The Effects of Cannabis Use in People With Schizophrenia on Clinical, Neuropsychological and Physiological Phenotypes
Official Title  ICMJE The Effects of Cannabis Use in People With Schizophrenia on Clinical, Neuropsychological and Physiological Phenotypes
Brief Summary Approximately 25% of people with schizophrenia abuse marijuana. These people may be using marijuana to self-medicate symptoms such as hallucinations (hearing or seeing things that are not heard or seen by others) or delusions (false beliefs i.e. people are harassing or persecuting them) or the depressed and anxious feelings brought on by these symptoms. Currently, it is unknown whether marijuana makes schizophrenia better or worse. Marijuana intoxication in people without schizophrenia generally causes decreased recall of words, may decrease reaction time and decrease inhibition. Additionally, marijuana may cause distractibility as demonstrated by difficulty keeping their eyes on a moving target and difficulty inhibiting their response to repetitive tones. However, marijuana may have different effects in schizophrenia. Receptors for cannabis (marijuana) are concentrated in the brain and maladjustment of the cannabinoid system may be associated with the difficulty in thinking found in schizophrenia. The proposed research project examines if clinical symptoms, learning, memory, inhibition and distractibility are improved or made worse by the acute ingestion of tetrahydrocannabinol (THC).
Detailed Description The trial will be a double two period (visit) blind cross-over trial with one arm dronabinol 10 mg one arm a placebo control. The order of doses and placebo will be randomized with the restriction that half of the subjects will receive each order. This counterbalances possible visit effects or learning effects associated with the visits. The use of an oral cannabis analog is not equivalent to smoking as the onset of action is slower. This is why people who use dronabinol for chronic pain prefer to smoke cannabis. There is no "high" associated with dronabinol. However, the active ingredients are the same, THC, which will have similar effects on the cannabinoid 1 receptor. Ethically, we did not feel we could ask people to smoke cannabis on one day of study. Subjects will present to the GCRC at 5:00 p.m. They will abstain from use of cannabis overnight. The following morning, at 8:00 a.m., the subject will provide a urine sample for a toxicology screen and a blood sample for quantitative THC levels. They will then be administered either 10 mg of dronabinol or an identical placebo on an alternate day. The subject will then have a baseline assessment of clinical positive and negative symptoms measured by the Brief Psychiatric Rating Scale (BPRS). The majority (70-90%) of people with schizophrenia smoke cigarettes. Thus, it is likely that in this population that smokes cannabis, 100% will also be cigarette smokers. The effects of nicotine via cigarette smoking on the endophenotypes studied is an acute effect, with a peak at about 5 minutes. To preclude nicotine effects on endophenotypes, we have the patient not smoke for 20 minutes prior to and during testing. Nicotine is quickly removed from the body when inhaled and its effects wear off within 20 minutes. Two hours after administration, the subject will perform the following tests: P50 auditory evoked potential- the recording will consist of the presentation of 5 sets of 16 click pairs with an intrapair interval of 500 ms heard through headphones with a 3-minute rest between sets. Brain wave responses will be recorded; neurocognitive assessment-the California Verbal Learning Test will measure verbal memory and the Stroop will measure inhibition; clinical symptom assessment- The BPRS will again be administered measure positive and negative symptoms; and a blood sample will be collected for quantitative THC levels. They will then be escorted by a Clinical Research Center nurse over to a laboratory at Colorado Psychiatric Hospital to perform smooth pursuit eye movements In performing smooth pursuit eye movements, they will watch a dot moving across a computer screen while infrared sensors that are placed just in front of their eyes record their eye movements. Each subject performs 3 trials of one minute each, with 2 minutes rest between each recording. Subjects will be reassessed by the BPRS for drug exacerbation of symptoms, will have vitals, will be checked for adverse effects, will perform a sobriety test (the standard test used in roadside testing i.e. walking a straight line and finger to nose testing) which will be assessed by Dr. Olincy, who is experienced in assessing sobriety, to assure that the patient is not acutely intoxicated and able to perform normal functions that require coordination. If they fail the sobriety test, they will be asked to remain in the (General Clinical Research Center (GCRC) until they can pass the sobriety test. Otherwise, they will then will be discharged at 5:00 p.m. Transportation to and from the GCRC will be by a provided cab service. Subjects will be randomized in blocks of 4 or 6 to the order in which they receive placebo or dronabinol. The interval between the two days of testing will be 1 week.
Study Type  ICMJE Interventional
Study Phase  ICMJE Phase 1
Phase 2
Study Design  ICMJE Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: Triple (Participant, Investigator, Outcomes Assessor)
Condition  ICMJE Schizophrenia
Intervention  ICMJE
  • Drug: Dronabinol
    dronabinol 10 mg one capsule by mouth at 8:00 a.m.
    Other Name: Marinol
  • Other: Placebo Comparator
    one capsule given by mouth at 8:00 a.m.
    Other Name: Sugar Pill
Study Arms  ICMJE
  • Active Comparator: dronabinol
    dronabinol 10 mg one capsule by mouth at 8:00 a.m.
    Intervention: Drug: Dronabinol
  • Placebo Comparator: sugar pill
    one capsule given by mouth at 8:00 a.m.
    Intervention: Other: Placebo Comparator
Publications * Not Provided

*   Includes publications given by the data provider as well as publications identified by ClinicalTrials.gov Identifier (NCT Number) in Medline.
 
Recruitment Information
Recruitment Status  ICMJE Terminated
Actual Enrollment  ICMJE
 (submitted: April 11, 2013)
13
Original Actual Enrollment  ICMJE Same as current
Actual Study Completion Date  ICMJE May 2011
Actual Primary Completion Date May 2010   (Final data collection date for primary outcome measure)
Eligibility Criteria  ICMJE

Inclusion Criteria:

  • Male and females
  • 18 and 50 years of age
  • Diagnosis of schizophrenia
  • Chronic cannabis users who have used for at least 1 year
  • Using cannabis at least once weekly
  • Currently being treated with antipsychotic medication
  • Must be on a the same dose of antipsychotic medication for at least 3 months.
  • Females of childbearing potential must use an adequate form of birth control while participating.
  • Participants will be required to have blood pressures greater than 90/60 and less than 140/90.

Exclusion Criteria:

  • Use of illicit drugs other than cannabis
  • Any psychiatric hospitalizations within 3 months
  • pregnancy in females
  • taking clozapine
Sex/Gender  ICMJE
Sexes Eligible for Study: All
Ages  ICMJE 18 Years to 50 Years   (Adult)
Accepts Healthy Volunteers  ICMJE No
Contacts  ICMJE Contact information is only displayed when the study is recruiting subjects
Listed Location Countries  ICMJE United States
Removed Location Countries  
 
Administrative Information
NCT Number  ICMJE NCT01832766
Other Study ID Numbers  ICMJE 05-0359
Has Data Monitoring Committee Yes
U.S. FDA-regulated Product Not Provided
IPD Sharing Statement  ICMJE Not Provided
Responsible Party University of Colorado, Denver
Study Sponsor  ICMJE University of Colorado, Denver
Collaborators  ICMJE National Alliance for Research on Schizophrenia and Depression
Investigators  ICMJE
Principal Investigator: Lynn Johnson, Pharm D University of Colorado, Denver
PRS Account University of Colorado, Denver
Verification Date August 2015

ICMJE     Data element required by the International Committee of Medical Journal Editors and the World Health Organization ICTRP