Simple Peripheral Markers for Inflammation in Drug-Naive, Comorbidity-Free Adolescents with Obsessive–Compulsive Disorder

Abstract

Obsessive-compulsive disorder (OCD) is a neuropsychiatric disorder with recurrent obsessions and/or compulsions that cause distress, time-consuming and/or significant disruption (1). The prevalence of OCD is %1-3 (2). OCD is divided into 2 groups according to the age of onset; early onset (12-14 years) and late onset (20-22 years) (3,4). Childhood-onset OCD is suggested to be distinguished with late-onset OCD by different etiopathogenic mechanisms (4,5). The pathophysiology of OCD is still unknown, recent studies have focused primarily on neurotransmitters, such as serotonin, dopamine, and glutamate (6,7). The previous studies have focused on environmental factors such as psychosocial stressors, trauma, and other infectious and their effects on inflammatory process. The inflammatory processes alter gene expression in a way that influences the serotoninergic and dopaminergic systems, catecholamine modulation, and glutamate pathways (8,9). Although the etiopathology is still unclear, these changes in the paths that process corticostriatal information are thought to be because of epigenetic mechanisms and have a causative role in OCD symptoms (10). Studies regarding the pathophysiology of OCD have emphasized the importance of immunological mechanisms (10-12). The relation between Group A β-hemolytic streptococcus infections and OCD onset or exacerbation in some children also show that immunological factors play a role in the etiology of OCD (13). Besides to streptococcus infection, other infectious diseases such as Borrelia burgdorferi, mycoplasma, Toxoplasma gondii, or Borna disease virus have been related with OCD (11,14).

Review: Inflammation and anxiety‐based disorders in children and adolescents – a systematic review and meta‐analysis

“…Ozyurt and Binici (2019) reported significantly higher total WBC and neutrophil levels among individuals with OCD. Contrastingly, Uçar et al (2019) and Ayaydin et al (2016) found no significant differences in total WBC and neutrophil levels. Uçar et al (2019) reported significantly lower lymphocyte levels among individuals with OCD, whereas Ayaydin et al (2016) and Ozyurt and Binici (2019) did not find any significant differences.…”

“…Contrastingly, Uçar et al (2019) and Ayaydin et al (2016) found no significant differences in total WBC and neutrophil levels. Uçar et al (2019) reported significantly lower lymphocyte levels among individuals with OCD, whereas Ayaydin et al (2016) and Ozyurt and Binici (2019) did not find any significant differences. Ozyurt and Binici (2019) included a sample of participants with co‐morbid anxiety disorders, specifically GAD, social anxiety disorder and specific phobia and reported higher inflammation among individuals with co‐morbidities.…”

“…A small negative effect was observed among three studies investigating lymphocyte levels, indicating lymphocytes were decreased in individuals with anxiety‐based disorders when compared with controls; however, this was not statistically significant (Hedges’ g = −0.20, 95% CI [−0.54, 0.14], p = .25). Moderate heterogeneity was reported between studies ( Q = 3.35, I 2 = 40, p = .19), although Uçar et al (2019) found individuals with OCD had significantly lower levels of lymphocytes, Ozyurt and Binici (2019) and Ayaydin et al (2016) did not find a statistically significant between‐group difference.…”

“…A small, nonsignificant between‐group difference was observed (Hedges’ g = 0.04, 95% CI [−0.76, 0.83], p = .93), with high heterogeneity ( Q = 17.21, I 2 = 88, p < .001). Although Ozyurt and Binici (2019) found individuals with OCD had significantly higher WBC counts, Ayaydin et al (2016) and Uçar, Murat, and Eray (2019) found individuals with PTSD and OCD, respectively, had lower but not statistically significant WBC counts.…”

“…A small, nonsignificant between‐group difference was observed (Hedges’ g = 0.13, 95% CI [−0.64, 0.89], p =.74), with large heterogeneity ( Q = 15.66 , I 2 = 87, p < .001). Specifically, Ozyurt and Binici (2019) found individuals with OCD had significantly higher neutrophil levels, whereas Uçar et al (2019) found no difference between groups, and Ayaydin et al (2016) reported lower, but not statistically significant levels of neutrophils among individuals with PTSD.…”