Objective: To investigate the causal relationship between tic disorders (TD) and their behavioral problems with persistent replication of cytomegalovirus (CMV) infection (i.e., persistent positivity for CMV-IgM antibodies). Methods: 1. A highly specific serological micro-enzyme-linked immunosorbent assay (ELISA) was used for antibody detection, with persistent positivity for CMV-IgM antibodies as an indicator of active CMV infection and replication; 2. Serum CMV-IgM antibody tests were conducted sequentially on 96 patients with TD, their parents, and healthy individuals; 3. Follow-up CMV-IgM antibody tests were performed on children and mothers with a history of abnormal medical conditions during pregnancy and infancy; 4. CMV-IgM antibody tests were conducted on 46 patients at admission, during treatment, and after discharge to observe the relationship between changes in antibody titers and the improvement or disappearance of clinical symptoms; and treatment outcomes were compared among 18 patients with comorbid obsessive-compulsive disorder (OCD) and 16 patients with a positive family history. Results: 1. The IgM positivity rate among children was 90.6% (87/96); the IgM positivity rate among healthy children was 17.8% (13/73), with a significant difference between the two groups (P < 0.01). The IgM positivity rate among fathers was 72.4% (21/29), while that among healthy males was 11.4% (4/35), showing a significant difference (P < 0.01). The IgM positivity rate among mothers was 89.9% (62/69), while that among healthy women was 15.6% (7/45), with a significant difference (P < 0.01). There was a significant positive correlation between the IgM positivity rates in the child and parent groups, which differed significantly from the IgM positivity rate in the healthy group. 2. During treatment, as the clinical manifestations of tics and behavioral problems gradually decreased or disappeared, the CMV-IgM antibody titers in patients also decreased synchronously or converted from positive to negative; 3. The cure rates in this group of TD patients, those with comorbid OCD, and those with a positive family history were 58.7% (27/46), 55.6% (10/18), and 53.3% (8/15), respectively, showing a significant positive correlation among the three groups. 4. Patients with a long disease course and complex conditions who adhered to antiviral treatment showed a gradual decrease in antibody titers or conversion from positive to negative, along with significant improvement in clinical symptoms. Conclusion: 1. Tic disorders and their behavioral problems are closely associated with active CMV infection and persistent replication; 2. CMV infection in children is closely related to infection in their parents; 3. A positive family history is a manifestation of familial aggregation due to CMV infection; 4. The timing of infection, duration, and differences in the autoimmune response in children can lead to significant variations in the pathological damage caused by viral replication to patient organs and tissues, as well as in clinical manifestations and outcomes.