The aim of this study is to explore the effectiveness of repetitive bilateral tDCS (left cathodal/right anodal) over the DLPFC on relapse in cocaine addicts. Craving, temptations and cognitive control functioning will be assessed as predictors of…
ID
Source
Brief title
Condition
- Other condition
Synonym
Health condition
Verslaving
Research involving
Sponsors and support
Intervention
Outcome measures
Primary outcome
Relapse probability in cocaine addicted patients as measured by means of EMA
after twice daily sessions of bilateral tDCS (left cathodal/right anodal) over
the DLPFC for five consecutive days. The primary study outcome is number of
relapse days at three months follow-up.
In addition, number of relapse days after one week, craving, temptations and
cognitive control will be assessed as possible predictors of relapse days at 3
months follow-up. Craving will be measured at the same moments in time as
relapse, by means of five single EMA items. Cognitive control will be
determined by inhibitory control and risky decision making. Inhibitory control
will be measured by performance on NoGo trials in the Go/NoGo task. Mean number
of pumps on the BART task will represent risk-taking.
Secondary outcome
The following control variables will be assessed: positive- and negative
affect, alcohol/ drug use, life satisfaction, amount of drug use in the past
month, starting age of using drugs and current age.
Background summary
Neurobiological substrates that are related to specific cognitive problems,
like the Prefrontal Cortex (PFC), seem to play an important role in the
aetiology and maintenance of SUD (Franken & van de Wetering, 2015).
Consequently, it is thought that modulation of brain activity related to these
cognitive problems would reduce addiction-related symptoms. Transcranial Direct
Current Stimulation (tDCS) is an electrical brain stimulation method that has
been explored in this area of interest. Previous studies suggest that
repetitive bilateral tDCS (left cathodal/right anodal) over the DLPFC is the
most effective treatment intervention in addiction. For example, Klauss and
colleagues (2014) found that 10 twice daily sessions of bilateral DLPFC tDCS
(left cathodal/ right anodal) reduced relapse probability for up to six months
in alcohol dependent patients. However, craving measured by retrospective
self-reports did not diminish. In contrast to Batista and colleagues (2015) who
did find diminished craving after 5 once daily sessions of bilateral tDCS (left
cathodal/ right anodal) in crack-cocaine addicted patients.
The effects of this tDCS method on relapse have not yet been studied in cocaine
addiction, despite the need for treatments reducing the high frequency of
relapses in cocaine addicted patients. Twice daily sessions seem to produce
long-term effects (Monte-Silva et al., 2013; Klauss et al., 2014) and would
therefore be particularly interesting to study in cocaine addiction.
It is expected that this particular tDCS method (bilateral (left cathodal/right
anodal) over the DLPFC twice daily for 5 consecutive days) will reduce relapse
probability. Furtermore, we expect this therapeutic effect to be associated
with diminished craving and enhanced cognitive control. Craving, temptations
and relapse, will be explored by means of Ecological Momentary Assessment
(EMA). The mixed results in previous studies of tDCS on craving may be
explained by the fact that craving in addiction is a momentary phenomenon which
is difficult to reliably measure with more traditional methods like
retrospective self-reports (Serre, Fatseas, Swendsen, & Auriacombe, 2015). EMA
offers a reliable and ecologically valid alternative, since this method makes
it possible to repeatedly measure craving at random moments of the day by means
of questionnaires via a mobile device.
Study objective
The aim of this study is to explore the effectiveness of repetitive bilateral
tDCS (left cathodal/right anodal) over the DLPFC on relapse in cocaine addicts.
Craving, temptations and cognitive control functioning will be assessed as
predictors of relapse to explore the working mechanism behind the therapeutic
effects of tDCS in addiction. It is expected that the tDCS intervention will
reduce relapse compared to a control condition (sham tDCS). In addition we
expect diminished craving and enhanced cognitive control functioning in the
tDCS group.
Study design
The design of the proposed experiment is a double-blind randomized
placebo-controlled trial. Eighty cocaine addicted patients will be randomly
assigned to two conditions, namely tDCS or sham (placebo). Both the researcher
as well as the patient will be blinded of the condition they are in (see
paragraph 7.2 research protocol).
During and after this two week period, participants have the possibility to
indicate temptations (TA) and relapse for up to three months. A weekly reminder
will be send to remind them of this possibility. Participants are asked to
return after these three months to fill in the same questionnaires and perform
the same psychological tasks as before, to measure the lasting effect of tDCS.
Intervention
One group will receive bilateral tDCS (left cathodal/right anodal) over the
DLPFC. The stimulation will take place two times daily for 13 minutes with a
rest interval of 20 minutes for five consecutive days. The stimulator will
induce tDCS with an intensity of 2.0 mA. The control group receives sham, for
which the stimulator will be gradually turned off after 30 seconds.
Study burden and risks
Participants will receive real-tDCS or sham twice daily for 13 min with an
interval of 20 min for five consecutive days. At baseline (before the tDCS
intervention) and a day after five days of treatment participants complete a
number of questionnaires and psychological tasks. In addition, participants
respond to a total of 15 single item questions about craving, affect, and
relapse first at baseline and then three times daily on a quasi-random basis by
means of EMA during the intervention period.
During and after this two week period, participants have the possibility to
indicate temptations (TA) and relapse for up to three months. A weekly reminder
will be send to remind them of this possibility. Participants are asked to
return after these three months to fill in the same questionnaires and perform
the same psychological tasks as before, to measure the lasting effect of tDCS.
Adverse effects of tDCS may be tingling and itching sensations under the
electrodes, headache, and tiredness (p.8 research protocol). However,
customarily applied tDCS protocols do not induce structural or functional
damage, and are well tolerated. Participants may however benefit from the tDCS
treatment.
Burgemeester Oudlaan 50
Rotterdam 3062 PA
NL
Burgemeester Oudlaan 50
Rotterdam 3062 PA
NL
Listed location countries
Age
Inclusion criteria
Aged between 18 and 65 years
Meeting the DSM-V criteria for cocaine dependence
The ability to speak, read, and write in Dutch at an eight-grade literacy level
No severe withdrawal signs or symptoms at baseline
Exclusion criteria
- Indications of severe psychopathology (psychosis, severe mood disorder) as assessed by a physician;
- A diagnosis of epilepsy, convulsions or delirium tremens during abstinence of cocaine;
- The intake of medications for psychiatric conditions;
- Any contraindication for electrical brain stimulation procedures such as electronic implants or metal implants;
- Pregnancy or breast-feeding.
Design
Recruitment
Followed up by the following (possibly more current) registration
No registrations found.
Other (possibly less up-to-date) registrations in this register
No registrations found.
In other registers
| Register | ID |
|---|---|
| CCMO | NL57262.078.16 |