Background/Objectives: The COVID-19 pandemic has had a profound impact on mental health worldwide, especially exacerbating Eating Disorders (EDs). This study aims to evaluate changes in the presentation and severity of EDs before and after the pandemic at the Regional Residential Center "Mariconda" in Salerno. Methods: This retrospective cohort study analyzed data from 162 patients admitted to the Regional Residential Center "Mariconda" between December 2018 and December 2023. The onset of pandemic restrictions in mid-2020 was the dividing line for the pre-COVID and post-COVID groups. Demographic and clinical data were collected, including age, gender, education level, previous hospital admissions, admission diagnosis, body mass index (BMI), and comorbidity with other psychiatric illnesses. Results: Of the 162 subjects, 115 were admitted post-pandemic. The post-pandemic group was significantly younger, had lower education levels, more frequent previous hospitalizations, and a higher frequency of severe comorbidity with other mental illnesses compared to the pre-COVID group. No significant differences were found between the groups regarding gender distribution, initial diagnosis upon admission, average and length of hospital stay. Conclusion: The COVID-19 pandemic has exacerbated the presentation and severity of EDs, particularly among younger individuals with lower educational attainment. These findings underscore the urgent need for targeted, integrated treatment approaches for EDs, especially global crises. Further research is essential to understand the long-term effects of the pandemic on EDs and to refine treatment strategies to better support affected individuals.

Background: We investigated, in an exploratory cross-sectional design, whether EDS-R score at admission showed adjusted cross-sectional associations with FT3, LDH, and ALT in patients with anorexia nervosa (AN) in residential treatment. Methods: A total of 164 patients with AN (first admission per patient) (AN-R: n = 122; AN-BP: n = 42; mean BMI 15.7 ± 1.7 kg/m²; 98.2% female) admitted consecutively to a specialist residential unit were included. Biochemical parameters were assessed within 48 h of admission using fully automated, internationally standardised analytical methods. FT3 was measured by electrochemiluminescence immunoassay (ECLIA) on automated immunoassay platforms, in accordance with standard immunometric procedures. ALT and LDH were measured by kinetic enzymatic (UV) methods following IFCC recommendations, using high-throughput clinical chemistry analysers. All analyses were performed in the core laboratory (Corelab) of the ASL Salerno hospital network, with internal and external quality control programmes in place. Exercise dependence severity was measured using the EDS-R Multivariable OLS and logistic regression analyses were conducted, adjusting for age, BMI, disease duration, and AN subtype. Results: Among 16 biochemical parameters examined, FT3 and LDH showed the largest Spearman correlations with EDS-R score, though neither survived Bonferroni correction for 16 simultaneous tests (threshold: p < 0.0031) (FT3: ρ = −0.224, p = 0.007; LDH: ρ = +0.244, p = 0.006). In multivariable regression, EDS-R score was independently associated with lower FT3 (β = −0.040, 95% CI [−0.072, −0.008], p = 0.016, n = 144) and higher LDH (β = +14.56, 95% CI [3.78, 25.35], p = 0.009, n = 124), while BMI was not significant in either model. By contrast, BMI was the sole significant predictor of ALT (β = −0.078, 95% CI [−0.136, −0.021], p = 0.008, n = 154), with the EDS-R score being non-significant (β = 0.019, p = 0.604). Binary logistic regression confirmed an association between EDS-R score and low-T3 syndrome (FT3 < 2.30 pg/mL): OR = 1.290 (95% CI [1.043–1.596], p = 0.019). Conclusions: In this exploratory cross-sectional study, EDS-R score showed adjusted associations with lower FT3 and higher LDH, but not ALT, at residential admission in AN, independent of BMI, age, AN subtype, and illness duration. These hypothesis-generating, cross-sectional findings cannot be interpreted as establishing prediction, causation, biomarker validity, or clinical utility. Prospective replication is required before any clinical implications can be considered.

Background: Anorexia nervosa (AN) is associated with extensive biochemical alterations at the time of clinical presentation. Despite distinct behavioural profiles, it remains unclear whether the restricting (AN-R) and binge–purge (AN-BP) subtypes differ in their biochemical profile at residential admission, a question with direct implications for clinical monitoring protocols. Methods: We conducted a retrospective cross-sectional study of 177 consecutive AN inpatients (AN-R: n = 130; AN-BP: n = 47; 98.3% female; mean BMI 15.8 ± 2.0 kg/m²; mean age 19.2 ± 5.5 years; 53.7% adolescents) admitted to a specialist residential unit (2018–2026). Thirty-five biochemical parameters were assessed. Unadjusted comparisons used Mann–Whitney U tests with rank-biserial effect sizes; multivariable logistic regression adjusted for BMI, age, and illness duration. Results: Overall, 98.3% of patients presented at least one biochemical anomaly (mean 4.4 ± 2.6 per patient). The most frequently abnormal parameters were LDH elevation (75.0%), vitamin D insufficiency (73.0%), low T3 syndrome (defined as low free triiodothyronine [FT3]) (58.0%), FT4 suppression (53.5%), ALT elevation (35.1%), and leucopenia (32.3%). AN subtype predicted none of these outcomes in unadjusted or multivariable analyses (all p > 0.10). The odds of presenting ≥3 simultaneous anomalies were not significantly associated with subtype, BMI, or illness duration in multivariable analysis. In contrast, older age independently predicted greater odds of low T3 syndrome (OR = 1.14 per year, 95% CI [1.00, 1.30], p = 0.045) and leucopenia (OR = 1.22 [1.06, 1.39], p = 0.004). No differences were observed between adolescents and adults in unadjusted comparisons. Conclusions: Despite their distinct behavioural profiles, no statistically significant biochemical differences were detected between AN-R and AN-BP at residential admission. These findings support routine standardised biochemical screening in all patients with anorexia nervosa admitted to residential care, regardless of behavioural subtype. Older age may identify a subgroup warranting closer endocrine and haematological monitoring.