Evaluation of Morning and Evening Serum Melatonin Levels in Generalized Anxiety Disorder

Abstract

Objective: Melatonin is a key regulator of circadian rhythm and has been suggested to be associated with psychiatric disorders. Evidence regarding the relationship between melatonin and generalized anxiety disorder (GAD) remains limited and methodologically heterogeneous. This study aimed to compare morning and evening serum melatonin levels in patients with GAD and healthy controls. Materials and Methods: This cross-sectional, observational case–control study included 35 patients diagnosed with GAD according to DSM-5-TR criteria and 50 healthy individuals. Venous blood samples were collected at 10:00 AM and 10:00 PM from different participant groups. Serum melatonin levels were measured using the ELISA method. Between-group comparisons were performed using the Welch-corrected independent samples t-test. Results: No significant difference was observed between groups in morning melatonin levels (p=0.183). Evening measurements also showed no statistically significant difference between groups (p=0.053). A significant morning–evening difference was observed in the control group (p=0.01), whereas no significant difference was found in the GAD group (p=0.71). A statistically significant difference in Δ values was observed between the groups (p=0.03). Conclusion: Absolute serum melatonin levels in patients with generalized anxiety disorder (GAD) were not found to differ from those of healthy individuals. However, the absence of the physiological evening increase observed in the control group may indicate a potential alteration in circadian melatonin organization in the GAD group. This finding should be confirmed by further studies involving repeated within-subject measurements and multi-time-point sampling.

Keywords

• Generalized anxiety disorder
• melatonin
• circadian rhythm
• serum melatonin level
• case-control study

Yaygın Anksiyete Bozukluğunda Sabah ve Akşam Serum Melatonin Düzeylerinin Değerlendirilmesi

Abstract

Amaç: Melatonin, sirkadiyen ritmin temel düzenleyicilerinden biri olup psikiyatrik bozukluklarla ilişkili olabileceği düşünülmektedir. Yaygın Anksiyete Bozukluğu (YAB) ile melatonin arasındaki ilişkiye dair bulgular sınırlı ve yöntemsel olarak heterojendir. Bu çalışmada, YAB hastaları ile sağlıklı kontrollerde sabah ve akşam serum melatonin düzeylerinin karşılaştırılması amaçlandı. Gereç ve Yöntem: Bu kesitsel, gözlemsel hasta–kontrol çalışmasına DSM-5-TR tanı kriterlerine göre YAB tanısı alan 35 hasta ve 50 sağlıklı birey dahil edildi. Venöz kan örnekleri sabah saat 10:00 ve akşam saat 22:00’de farklı katılımcı gruplarından elde edildi. Serum melatonin düzeyleri ELISA yöntemi ile ölçüldü. Gruplar arası karşılaştırmalarda Welch düzeltmeli bağımsız örneklem t-testi kullanıldı. Bulgular: Sabah melatonin düzeyleri açısından gruplar arasında anlamlı fark saptanmadı (p=0,183). Akşam ölçümlerinde gruplar arasında fark istatistiksel olarak anlamlı değildi (p=0,053). Kontrol grubunda sabah–akşam farkı anlamlı iken (p=0,01), YAB grubunda anlamlı bulunmadı (p=0,71). Gruplar arasında Δ değerleri açısından istatistiksel olarak anlamlı fark saptandı (p=0,03). Sonuç: YAB hastalarında mutlak serum melatonin düzeyleri sağlıklı bireylerden farklı bulunmamıştır. Bununla birlikte kontrol grubunda gözlenen fizyolojik akşam artışının YAB grubunda belirgin olmaması, sirkadiyen melatonin organizasyonunda olası bir farklılığa işaret edebilir. Bu bulgunun birey içi tekrarlı ölçümler ve çok zamanlı örnekleme içeren ileri çalışmalarla doğrulanması gerekmektedir.

Keywords

• Yaygın anksiyete bozukluğu
• melatonin
• sirkadiyen ritim
• serum melatonin düzeyi
• hasta-kontrol çalışması

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