The role of serotonin in compulsive behaviour in humans (OCD-project)

The OCD-project is a double-blind placebo-controlled study of individuals with the Obsessive-Compulsive Disorder (OCD) and healthy individuals matched on sex and age. Here, we evaluate how a three-week treatment with the drug selective serotonin reuptake inhibitor (SSRI) affects the serotonin receptor 4, measured with Positron Emission Tomography (PET), and compulsive behaviour, measured with functional Magnetic Resonance Imaging (fMRI) and sophisticated neuropsychological testing (Cambridge Neuropsychological Test Automated Battery and EMOTICOM). The project is a collaboration between NRU and Professor and cognition expert Trevor Robbins and post doc Paula Banca from The University of Cambridge, UK.

We are currently recruiting OCD-patients. The currrent enrollment status in the project is displayed to the left.
If you are interested in participating, please click here to know more.

Inappropriately repeating a behaviour, such as repeating washing rituals, symmetry compulsions or checking rituals, is what we refer to as compulsive behaviour. That is a core and disabling symptom in OCD. Individuals with OCD are treated with SSRIs that prolong serotonin signalling by blocking its reuptake in the synapse. However, it remains unknown how serotonin and compulsive behaviour are associated, a central question that we are addressing in this study.
Fig 1: Flow-chart of the study design

Figure 2. An
experiment of breaking habits during functional MRI: The experiment is divided into three parts: A) participants are instructed to do a certain goal-directed behaviour, B) participants are building up a simple habit by repeating a behaviour a vast number of times, C) the goal-directed behaviour and the newly built-up habit are now subconsciously in competition, and the participants are required to inhibit the habit to successfully complete the task. The paradigm is described by Zwosta et al., 2018.