Objective To explore the neuro-metabolism and thyroid function in female adolescents with bipolar depression and obsessive-compulsive symptoms（ OCS）. Methods From January 2024 to February 2025， 35 female adolescents with bipolar depression who received outpatient or inpatient treatment at the Department of Clinical Psychology of People's Hospital of Xinjiang Uygur Autonomous Region were selected as study subjects. According to whether there was significant OCS and the Children's Yale-Brown Obsessive Compulsive Scale（ CY-BOCS） score， patients were divided into an OCS group（ n=20， CY-BOCS score ≥16） and non- OCS group（ n=15， CY-BOCS score≤7）. The 24-item Hamilton Depression Scale（ HAMD-24） and Young Mania Rating Scale（ YMRS） were used to assess patients' depressive and manic symptoms， respectively. 1H-magnetic resonance spectroscopy（ 1H-MRS） was employed to assess metabolic levels of N-acetyl-aspartate（ NAA）， choline（ Cho）， myo-inositol（ mI）， and glutamate/glutamine complex（ Glx）， and creatine（Cr） in the ventromedial prefrontal cortex（ vmPFC） of patients. Chemiluminescent immunoassay was utilized to detect serum thyroid function indicators. Binary Logistic regression was used to examine the association between neuro-metabolism， thyroid function， and OCS. The calibration and discriminatory performance of the model were assessed using the Hosmer-Lemeshow test and receiver operating characteristic（ ROC） curve. Results Patients in OCS group had higher HAMD-24 scores［ （26.8±5.8） vs.（ 23.2±3.9）］ and longer disease duration［ 3.0（ 1.0，5.0） years vs. 1.0（ 0.5，2.0） years］ than those in non-OCS group， with statistically significant differences（ t=-2.070， Z= -2.190； both P＜ 0.05）. Patients in OCS group exhibited lower NAA/Cr values and FT3 levels compared to non- OCS group［ 1.56（ 1.18， 1.72） vs. 1.87（ 1.72，2.04），（ 3.13±0.49） vs（. 3.48±0.50）］， with statistically significant differences（ Z=-3.200， t=2.049； both P＜0.05）. Binary Logistic regression analysis revealed that the NAA/Cr value［ OR=0.091， 95%CI（ 0.014，0.588）， P=0.012）］ was a protective factor for patients with OCS， with a statistically significant difference（ Hosmer-Lemeshow test χ2=9.00， P=0.253； area under the ROC curve was 0.820， P ＜ 0.001）. Conclusions Among female adolescents with bipolar depression， those with comorbid OCS exhibit severe depression， long disease duration， and low NAA/Cr values and serum FT3 levels in vmPFC. Decreased NAA/Cr is independently associated with comorbid OCS， suggesting its potential as a biological marker for identifying such comorbidities.