Working Memory Training for Substance Dependent Individuals

Depression Clinical Trial

Official title:

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

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT02119949
• Other study ID #: 2
• Status: Completed
• Phase: N/A
• First received: April 8, 2014
• Last updated: August 20, 2014
• Start date: May 2012
• Est. completion date: June 2014

Study information

• Verified date: August 2014
• Source: Erasmus Medical Center
• Contact: n/a
• Is FDA regulated: No
• Health authority: Netherlands: Medical Ethics Review Committee (METC)Netherlands: The Central Committee on Research Involving Human Subjects (CCMO)
• Study type: Interventional

Clinical Trial Summary

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.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 180
• Est. completion date: June 2014
• Est. primary completion date: June 2014
• Accepts healthy volunteers: No
• Gender: Both
• Age group: 16 Years to 67 Years

Eligibility

Inclusion Criteria:

• Substance dependency: cocaine, cannabis or alcohol

Exclusion Criteria:

• Age below 16 or above 67

• Current psychosis

• Neurological complaints

Study Design

Allocation: Randomized, Endpoint Classification: Efficacy Study, Intervention Model: Parallel Assignment, Masking: Double Blind (Subject, Investigator), Primary Purpose: Treatment

Related Conditions & MeSH terms

• Addiction
• Anxiety
• Depression
• Substance Dependency

Intervention

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 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.

Locations

Country	Name	City	State
Netherlands	Bouman Clinic	Rotterdam	Zuid Holland

Sponsors (1)

Lead Sponsor	Collaborator
Erasmus Medical Center

Country where clinical trial is conducted

Netherlands, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Other	Change in Barratt Impulsivity Scale-11 score on pre and post training and follow up after two months	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)	No
Other	Change in Stroop score on pre and post training and follow up after two months	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)	No
Other	Change in Beck Depression Inventory - Second Edition (BDI-II) score on pre and post training and follow up after two months	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)	No
Other	Change in State-Trait Anxiety Inventory (STAI) score on pre and post training and follow up after two months	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)	No
Other	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.	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)	No
Primary	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)	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)	No
Secondary	Change in Digit Span score on pre and post training and follow up after two months	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)	No
Secondary	Change in Reading Span partial-scredit uni score on pre and post training and follow up after two months	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)	No