Effects of Transcranial Direct Current Stimulation (tDCS) in Gambling Disorder

The Role of Neuromodulation for Cognitive Processing and Behavioural Inhibition in Gambling Disorder

Gambling disorder is associated to high impulsivity and excessive risk-taking behaviour. These behavioural characteristics related to addiction are linked to cognitive processes in specific brain areas located in the prefrontal cortex (PFC).

With the aim of studying the role of PFC in gambling disorder, the investigators employ transcranial current direct stimulation (tDCS), a noninvasive brain stimulation technique that applies a very weak electrical current to the superficial areas of the brain.

The clinical phase of the research consists on studying the effects of tDCS in combination with cognitive behavioural therapy (CBT) in patients that attend the United Kingdom (UK) National Problem Gambling Clinic. The main objective of the project is to investigate whether the combination of tDCS and CBT can help to decrease impulsivity and risk-taking behaviour and therefore improve the treatment for gambling disorder.

The investigators aim to have a total of 32 participants diagnosed with gambling disorder with the Problem Gambling Severity Index (PGSI). There will be 16 participants per group having two different groups (real stimulation and sham). Real stimulation involves the application of tDCS stimulation and sham condition is used as a control (similar to a placebo).

Participants will attend 8 weekly sessions where they receive tDCS stimulation for 20 minutes, while complete CANTAB cognitive tasks that measure cognitive processes such us control inhibition and risk-taking behaviour. Electroencephalography (EEG) activity will be measured before and after tDCS.

Participants will also complete cognitive questionnaires (Pathological Gambling adapted Yale-Brown Obsessive Compulsive Scale (PG-YBOCS), Gambling Symptom Assessment Scale (G-SAS) and Visual Analogue Scale (VAS) for gambling cravings.

Inclusion Criteria:

• Male or females between 18-65 years old diagnosed with disordered gambling based on the Problem Gambling Severity Index (PGSI) who can speak and read English and don't have any of the exclusion criteria.

Exclusion Criteria:

1. History or evidence of chronic or residual neurological disease.
2. A pacemaker or deep brain stimulation.
3. Metal implants in head or neck area (e.g. postoperative clips after intracerebral aneurysm; arterial aneurysm in the vascular system, implantation of an artificial hearing aid).
4. Intracerebral ischemia/history of bleeding.
5. Prior evidence of epileptic seizures, history of epilepsy.
6. History of head injury with loss of consciousness.
7. Any serious medical conditions (disease of the internal organs).
8. Pregnancy or breast-feeding.
9. Negative prescreening from the clinic psychiatrist.