Working Memory Training for Substance Dependent Individuals

August 20, 2014 updated by: Ingmar Franken, Erasmus Medical Center

A Randomized Double-blind Placebo-controlled Trial to Working Memory Training in Substance Abusers

Background: Substance abusers show impaired working memory (WM) functioning. Promising findings show training WM results in an improved working memory capacity (WMC) and a decrease of clinical symptoms in a range of disorders, including alcohol addiction.

Aim: To test the effect of a WM training in addition to treatment as usual (TAU) on substance use, craving, WMC, impulsivity, attention bias and psychopathology.

Design: A randomized double-blind placebo-controlled trial with a parallel group design. The WM training adapted to participants' WMC whereas the placebo training consisted of non-adaptive easy versions of these tasks.

Setting: Two departments of an addiction treatment clinic in Rotterdam, the Netherlands.

Participants: 120 inpatients diagnosed with an alcohol, cannabis or cocaine dependency who were in treatment as usual .

Measurements: Primary outcome measures: Substance use and craving. Secondary outcome measures: WMC, impulsivity, attention bias and psychopathology. Participants were assessed before and after 24 sessions of WM training as well as two months after the training.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

180

Phase

  • Not Applicable

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

  • Netherlands
    • Zuid Holland
      • Rotterdam, Zuid Holland, Netherlands, 3084 LD
        • Bouman Clinic

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

16 years to 67 years (Child, Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Description

Inclusion Criteria:

  • Substance dependency: cocaine, cannabis or alcohol

Exclusion Criteria:

  • Age below 16 or above 67
  • Current psychosis
  • Neurological complaints

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 Assignment
  • Masking: Double

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Working memory training
Behavioral: Working memory training
The working memory training started the day after the pre-test and included 24 sessions of 25 minutes each. Participants trained, under supervision of an experimenter, on weekdays in the clinic. The training consisted of two tasks: the Symmetry Span and the N-back Task. Participants in the experimental group executed versions of these task that adapt to their working memory capacity, to train their working memory optimally.
Placebo Comparator: Placebo training
Behavioral: Placebo training
The working memory training started the day after the pre-test and included 24 sessions of 25 minutes each. Participants trained, under supervision of an experimenter, on weekdays in the clinic. The training consisted of two tasks: the Symmetry Span and the N-back Task. Participants in the placebo group executed easy versions of these task that did not adapt to their level, to prevent training.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Craving: Desires for Alcohol Questionnaire and Desires for Drug Questionnaire score change and Obsessive Compulsive Drug Use Scale and Obsessive Compulsive Drinking Scale score change between pre and post training and follow up (two months after post)
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)

The 14-item Desires for Drug Questionnaire (DDQ) and the 13-item Desires for Alcohol Questionnaire (DAQ) measure instant craving to respectively drug and alcohol. The DDQ is based on the DAQ.

The Obsessive Compulsive Drug Use Scale (OCDUS) and Obsessive Compulsive Drinking Scale (OCDS) measure the subjective interference and distress caused by respectively drug and alcohol related thoughts and compulsive-behavior patterns.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)

Secondary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Digit Span score on pre and post training and follow up after two months
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
The Digit Span task consists of two parts: the forward Digit Span is a frequently used measure for short term memory, an important subcomponent of the memory system (Shipstead, Redick, & Engle, 2012) and the backward version measures WM.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
Change in Reading Span partial-scredit uni score on pre and post training and follow up after two months
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
The Reading Span measures the processing and storage functions of WM (Shipstead et al., 2012), specifically participants' ability to shift between two tasks and to cope with proactive interference.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)

Other Outcome Measures

Outcome Measure
Measure Description
Time Frame
Change in Barratt Impulsivity Scale-11 score on pre and post training and follow up after two months
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
The 30-item Barratt Impulsivity Scale-11 (BIS-11) measures impulsivity.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
Change in Stroop score on pre and post training and follow up after two months
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
The Stroop measures participants' attention bias for addiction related stimuli.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
Change in Beck Depression Inventory - Second Edition (BDI-II) score on pre and post training and follow up after two months
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
The Beck Depression Inventory - Second Edition (BDI-II) measures the severity of depression in 21 statements, with four levels of increasing severity each.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
Change in State-Trait Anxiety Inventory (STAI) score on pre and post training and follow up after two months
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
The State-Trait Anxiety Inventory (STAI) measures self-reported anxiety in 40 questions on a 4-point scale. The questionnaire consists of two parts; state and trait anxiety, respectively transient and dispositional anxiety.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
Change in substance use, measured with the Addiction Severity Index over pre-, post (1 day after training) and follow-up (2 months after post-test) measurements.
Time Frame: Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)
The Addiction Severity Index (ASI) is a semi-structured interview that measures the severity of addiction in 25 questions concerning seven problem areas: medical problems, employment problems, drug use, alcohol use, family and social problems, criminality, and psychiatric problems. We used three of these questions to assess the severity of participants' abuse problems.
Pre (baseline), post (after 4 weeks of training-starting 1 day after pre-test) and follow-up (2 months after post-test)

Collaborators and Investigators

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

Sponsor

Erasmus Medical Center

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

May 1, 2012

Primary Completion (Actual)

June 1, 2014

Study Completion (Actual)

June 1, 2014

Study Registration Dates

First Submitted

April 8, 2014

First Submitted That Met QC Criteria

April 18, 2014

First Posted (Estimate)

April 22, 2014

Study Record Updates

Last Update Posted (Estimate)

August 21, 2014

Last Update Submitted That Met QC Criteria

August 20, 2014

Last Verified

August 1, 2014

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • 2

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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