Islam, Md. RabiulArthi, Nisat Jahan2026-05-112026-05-1120262026-05ID 22346034http://hdl.handle.net/10361/28235Cataloged from PDF version of thesis.Includes bibliographical references (pages 73-81).This thesis is submitted in partial fulfillment of the requirements for the degree of Bachelor of Pharmacy, 2026.Obsessive-Compulsive Disorder (OCD) is a prevalent, chronic, neuropsychiatric condition in-creasingly linked to immune-inflammatory mechanisms. This study aimed to measure serum IL-5 levels in Bangladeshi OCD individuals and to examine their association with symptom severity. The study was conducted at Government National Institute of Mental Health (NIMH) & Hospital, Dhaka, Bangladesh. Total number of samples were 428 participants including 220 OCD individu-als and 208 healthy persons. Diagnoses were confirmed using DSM-5 criteria. On the other hand, Y-BOCS evaluated symptom severity. A standardized laboratory procedure was followed to meas-ure serum IL-5 levels. Statistical analysis was performed to compare the groups and assess corre-lation. Serum IL-5 level comparisons demonstrated slightly higher mean IL-5 levels in OCD pa-tients than controls (2.43±1.19 pg/ml vs 2.17±1.12 pg/ml). A substantial difference was found (P=0.020). However, the correlation between serum IL-5 levels and Y-BOCS scores was weakly negative (r =-0.076) and not significant (P=0.262). In addition, substantial variability and overlap were observed between the two groups. In conclusion, although IL-5 levels are somewhat elevated in Bangladeshi OCD patients, no significant association with OCD symptom severity was identi-fied. This research describes that IL-5’s implication is limited as a single biomarker. This limitation highlights the need for further research involving multiple immune biomarkers.90 pagesenBRAC University theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission.Obsessive-compulsive disorderInterleukin-5CytokineNeuroinflammationBiomarkersObsessive-compulsive disorder.Interleukin-5--Receptors.Nervous system--Degeneration.Biochemical markers.Thesis