The Cognitive Enhancing Effects of D-Cycloserine Among Non-Demented Elderly

February 8, 2021 updated by: Hartford Hospital
The goal of this study is to determine whether a study medication (d-cycloserine) improves the ability of older adults to perform on tests of neuropsychological functioning. Tests of neuropsychological functioning assess attention, memory, and executive functioning skills (for example, problem-solving, planning and organizing skills). It was hypothesized that participants who received study medication would perform better on neuropsychological tests than would participants who received the sugar pill.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

Accumulating data support the augmenting effects of d-cycloserine (DCS) when combined with exposure-based treatment for anxiety disorders. Additional research is needed to determine whether DCS facilitates other forms of cognitive processing (e.g., attention, memory, executive functioning) that are involved in cognitive behavioral therapies which do not rely on extinction as a mechanism of action. This question is particularly important among older adults who have experienced normal age-related declines in cognitive functioning, which may interfere with their ability to benefit from cognitive-behavioral therapies. The aim of the current study was to determine the cognitive enhancing effects of DCS on neuropsychological test performance among healthy older adults. It was hypothesized that participants who received d-cycloserine would demonstrate superior performance on neuropsychological tests than would participants who received placebo.

Study Type

Interventional

Enrollment (Actual)

51

Phase

  • Phase 2

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • United States
    • Connecticut
      • Hartford, Connecticut, United States, 06106
        • Anxiety Disorders Center, Institute of Living/Hartford Hospital

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

60 years and older (ADULT, OLDER_ADULT)

Accepts Healthy Volunteers

Yes

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • age 60 or older
  • native English speaker

Exclusion Criteria:

  • diagnosis of current psychiatric disorder
  • substance abuse past 3 months
  • cognitive impairment
  • neurological disorder
  • poor health or unstable medical condition
  • positive toxicology screen
  • current use of isoniazid
  • current use of trecator
  • severe renal insufficiency

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: TREATMENT
  • Allocation: RANDOMIZED
  • Interventional Model: PARALLEL
  • Masking: TRIPLE

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Placebo Comparator: Sugar Pill
Drug: Sugar Pill
Single oral administration 250 mg Sugar Pill
Other Names:
  • Placebo
Experimental: Medication
250 mg d-cycloserine
Drug: d-cycloserine
single oral administration of 250 mg d-cycloserine
Other Names:
  • Seromycin

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
California Verbal Learning Test-II (CLVT-II)
Time Frame: Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without patient follow up. Scores for the experimental and control group were compared.
The CLVT-II is an assessment of verbal learning and memory which measures recall and recognition scores, encoding strategies, learning rates and error types. A list learning task with 16 words from 4 semantic categories are read over a series of 5 list presentations. Recall is assessed after learning and at a 20-minute delay. Software produces a report that computes raw and standardized scores. Our dependent variable was the age adjusted t-score for total number of words recalled after 5 trials. A higher score indicated better recall. The maximum possible score was 80 and a minimum was 0.
Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without patient follow up. Scores for the experimental and control group were compared.

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Continuous Performance Test
Time Frame: Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Sustained attention was assessed using the Penn version of the Continuous Performance Test. During the CPT the participant responds to a target stimulus (e.g., the letter "A"), while inhibiting responding to distractor stimuli. Reaction time to correct targets (true positives) was used as the dependent variable. Faster reaction times indicate better performance.
Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Controlled Oral Word Association Test
Time Frame: Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
The Controlled Oral Word Association Test is a measure of the ability to orally generate words to a phonemic cue within a 60-second time interval. Age and education-adjusted t-scores were used as the dependent variable. A T-score of 50 is equal to the mean, with a standard deviation of 10 points. A higher T-score is a more favorable outcome.
Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Wisconsin Card Sort Test
Time Frame: Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
The Wisconsin Card Sorting Test is a test of rule-learning and conceptual flexibility. The participant is required to learn to sort a series of cards according to one of three principles (color, form or number) based on response feedback. The age-adjusted t-score for total number of errors was used as a dependent variable. A T-score of 50 is equal to the mean, with a standard deviation of 10 points. A higher T-score is a more favorable outcome.
Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Trails B
Time Frame: Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Trails B is a measure of cognitive flexibility. The participant alternates sequencing between numbers and letters. An age and education-adjusted t-score for time to complete the exercise was used as the dependent variable. A T-score of 50 is equal to the mean, with a standard deviation of 10 points. A higher T-score is a more favorable outcome.
Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Stroop
Time Frame: Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
The Stroop Color Word Test is a measure of selective attention and cognitive flexibility. This measure consists of three conditions: word reading, color naming and color-word naming. The interference score (t-score) was used as the dependent variable. A T-score of 50 is equal to the mean, with a standard deviation of 10 points. Higher t-scores represent a more favorable outcome.
Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Implicit Memory Task
Time Frame: Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up
Participants were presented with 32 stimulus words: 16 neutral and 16 threatening words. After a filler task (crossing out 8's on a sheet of randomized numbers) participants completed a response sheet including the stems for the 32 words presented to participants (primed words) along with stems for the 32 unprimed words. Participants were instructed to write down the first word that came to mind that completes each word stem. The priming effect was determined using the difference score between the correct number of stem completions for primed versus unprimed words. This is a value determined for each participant using the following equation: correct number of stem completions for primed word minus the correct number of stem completions for unprimed words. A larger difference score indicates a stronger implicit memory.
Outcome measures will be collected during a single neuropsychological testing administration lasting approximately 3 hours without further patient follow-up

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Hartford Hospital

Investigators

  • Principal Investigator: Gretchen J. Diefenbach, Ph.D., Hartford Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start

January 1, 2008

Primary Completion (Actual)

February 1, 2009

Study Completion (Actual)

February 1, 2009

Study Registration Dates

First Submitted

May 24, 2011

First Submitted That Met QC Criteria

May 25, 2011

First Posted (Estimate)

May 27, 2011

Study Record Updates

Last Update Posted (Actual)

February 18, 2021

Last Update Submitted That Met QC Criteria

February 8, 2021

Last Verified

October 1, 2019

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 126177
  • DIEF002352HI (Other Grant/Funding Number: Hartford Hospital)

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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