Impulsivity and inflammatory markers in obsessive-compulsive disorder

Objective: Impulsivity is a multidimensional structure shaped by different neuropsychological and neurobiological processes. The presence of impulsivity in patients with obsessive compulsive disorder (OCD) is important for the management of the disease, choice of treatment, and evaluation of long-term results. In this study, it was aimed to evaluate the sub-dimensions of impulsivity in OCD and to investigate the relationship between inflammatory processes and impulsivity in OCD. Methods: Forty patients who admitted to the Karadeniz Technical University (KTU) Faculty of Medicine Psychiatry Outpatient Clinic between August 2021 and May 2022 and were diagnosed with OCD according to the DSM-5 diagnostic criteria, accepted to participate in the study and met the eligibility criteria were included in the study. Forty healthy volunteers matched with these patients in terms of gender, age and education level were included in the study as a control group. Impulsivity was evaluated with self-report scales and neuropsychological tasks: Barratt Impulsivity Scale (BIS), UPPS Impulsive Behaviour Scale (UPPS), Go/no-go Task, Iowa Gambling Task (IGT), Balloon Analogue Risk Task (BART). Blood samples taken from the patient and healthy volunteer groups were centrifuged and CRP, TNF-alpha, IL-1β and IL-6 levels were studied in serum by ELISA method. Results: In our study, it was shown that the OCD group was more impulsive than the control group in the dimensions of BDI attention and UPPS urgency. There was no difference between the groups in neuropsychological tasks. A moderate positive correlation was found between symptom severity and UPPS-urgency and UPPS-total scores in OCD patients. While no relationship was found between OCD symptom severity and IGT, a positive correlation was found between the comission errors, which reflects inadequate response inhibition in YYT, and the number of total pumping, total burst, and blue balloon corrected pumping, reflecting risk-taking behavior in BART. CRP, TNF-α, IL-1β and IL-6 levels were found to be significantly higher in the OCD group than in the control group. A moderate negative correlation was found between CRP and TNF-α levels and Y-BOCS general severity score in OCD patients. In OCD patients, there was also a negative correlation between TNF-α level and BDI-non planning, BDI-attention and UPPS-total scores; There was a moderate negative correlation between IL-6 level and UPPS-perseverance score. No relationship was found between inflammatory markers and behavioral tests. Conclusion: In our study, especially in OCD patients, it was determined that the dimensions of attention and urgency impulsivity were increased, and it was also shown that as the severity of OCD symptoms increased, inadequate response inhibition and risk-taking behavior increased. A relationship was found between inflammation and OCD symptom severity and impulsivity dimensions. However, further research on the dimensions of impulsivity in OCD, as well as the effect of inflammation on the common neurobiological pathways of OCD and impulsivity, should be examined in further studies. Key Words: Obsessive compulsive disorder, impulsivity, inflammation.