Background and Objectives: Keratoconus (KC) is a progressive corneal ectasia with multifactorial etiology, increasingly studied for potential associations with psychiatric disorders. This systematic review aimed to evaluate recent evidence linking KC with depression and other psychiatric conditions, including psychotic disorders, personality disorders, attention deficit hyperactivity disorder (ADHD), Tourette syndrome (TS), autism spectrum disorder (ASD), and obsessive–compulsive disorder (OCD). Materials and Methods: Following PRISMA guidelines, PubMed, ScienceDirect and SpringerLink were searched for English-language observational studies published since 2015 that examined psychiatric disorders in adults with keratoconus. We excluded reviews, case reports, pediatric, non-English, and inaccessible articles. Study quality was assessed using the Newcastle–Ottawa Scale and JBI Checklist. Data were narratively summarized and tabulated—without meta-analysis due to heterogeneity. Results: Twelve studies met inclusion criteria, including 41,906 KC patients and 63,267 controls. Eleven studies investigated depression and one ADHD. Findings on depression were mixed: five studies showed higher depressive symptoms among KC patients, while others found no significant association. Most were cross-sectional and of moderate-to-high quality. The single study on ADHD reported a higher prevalence of KC in males, but no evidence of casual association. Evidence on TS, ASD, and OCD was scarce and largely limited to case reports. The review was limited by heterogeneous methodologies, small sample sizes, an absence of longitudinal data, and reliance on self-report or registry data. Conclusions: Current evidence indicates increased psychological burden among some individuals with KC, particularly regarding depressive symptoms, yet casual relationships remain unproven. Male ADHD patients may have an elevated risk of KC, especially in the presence of eye rubbing. Registration: Not registered.

Background: Electroconvulsive therapy (ECT) remains an effective intervention for severe and treatment-resistant psychiatric disorders. While acute response to ECT is well established, clinical predictors of long-term outcomes remain insufficiently characterized. This study examines the impact of illness duration on long-term ECT effectiveness, operationalized specifically as the amount of time elapsed from treatment completion to psychiatric rehospitalization. By controlling for primary diagnosis, psychiatric comorbidities, sleep disorders, and number of ECT sessions, this study aims to clarify the role of illness chronicity in sustaining remission and reducing relapse risk, while recognizing rehospitalization as a primary indicator of long-term clinical stability. Methods: We conducted a retrospective cohort study of 249 patients treated with ECT at a tertiary psychiatric hospital. Time to first psychiatric rehospitalization following completion of ECT was used as a proxy for relapse. Illness duration was analyzed alongside primary diagnosis, psychiatric comorbidities, sleep disorders, and number of ECT sessions to assess its independent association with long-term outcomes. Results: Nearly half of patients (44.6%) demonstrated sustained clinical benefit, defined by delayed or absent rehospitalization during a three-year follow-up period. Shorter illness duration emerged as a key predictor of more durable remission. Patients with illness duration below 15 years, and particularly those with less than 5 years of illness, experienced significantly longer periods without rehospitalization compared with individuals with longer disease trajectories, despite the latter often receiving more ECT sessions. Conclusions: Shorter illness duration is associated with improved long-term outcomes following ECT, suggesting that earlier intervention may enhance treatment durability. These findings support reconsidering ECT earlier in the course of treatment-resistant psychiatric disorders. Prospective studies integrating clinical, cognitive, and biological markers are warranted to improve patient selection and develop personalized ECT strategies.