Research Information System
BMC Psychiatry, vol.26, no.1, 2026 (SCI-Expanded, Scopus)
Background: Obsessive-Compulsive Disorder (OCD) and Trichotillomania (TTM) are classified together as Obsessive-Compulsive and Related Disorders, yet their distinct neurobiological underpinnings remain poorly understood. This study represents the first untargeted metabolomic analysis comparing adolescents with OCD and TTM to identify differential metabolic signatures. Method: This cross-sectional study included 62 female adolescents aged 10–18 years: 20 with OCD, 22 with TTM, and 20 healthy controls. Plasma samples were analyzed using liquid chromatography-quadrupole time-of-flight mass spectrometry (LC-Q-TOF/MS). Metabolomic data were processed using MZmine 2.53 and MetaboAnalyst 6.0, with metabolites showing |log₂(fold change)| > 0.585 (corresponding to fold change > 1.5 or < 0.67) and p < 0.05 considered significant. Results: Exploratory principal component analysis showed visual separation of the OCD group from healthy controls, while the TTM group showed partial overlap with controls. In OCD versus controls, linoleic acid (LA) was markedly decreased (FC: 0.02), while trihexosylceramide (FC: 15.48) and 7a,12a-dihydroxy-cholestene-3-one (FC: 4.33) were significantly elevated. TTM showed elevated arachidonic acid (AA) (FC: 9.60) and trihexosylceramide (FC: 13.42), with severely reduced biocytin (FC: 0.01) compared to controls. Direct comparison between disorders revealed LA (FC: 51.39) and AA (FC: 3.55) were higher in TTM versus OCD, while biocytin (FC: 0.10) was lower. These findings suggest that OCD and TTM exhibit distinct patterns of metabolite differences. Conclusion: OCD showed reduced LA levels, consistent with potential perturbations in omega-6 metabolism. TTM showed elevated AA levels and reduced biocytin, consistent with previously reported oxidative stress and altered energy metabolism in this disorder. These metabolic differences represent candidate metabolites warranting targeted validation and may provide preliminary insights into distinct neurobiological mechanisms rather than direct clinical applicability. Clinical trial number: Not applicable.