Objective: Diagnostic delay is one of the major problems for patients with predominantly antibody deficiencies (PAD) that can lead to anxiety and depression disorders, like in other chronic diseases. We aimed to detect the frequencies of anxiety and depression in PAD patients. The second aim was to determine the influence of diagnosis delay on the patients` anxiety and depression.

Materials and Methods: In this prospective study, 40 patients and 50 healthy controls answered the Hospital Anxiety and Depression Scale (HADS). We compared the anxiety, depression, and the total scores of the patients and the healthy controls. We divided the patients into two groups as delayed and early diagnosed patients according to median diagnostic delay year and compared the HADS scores of the two groups.

Results: The anxiety, depression and the total scores of PAD patients were significantly higher compared to the healthy controls; (p=0.001, p=0.001, p=0.001), respectively. The HADS scores were significantly higher in the delayed diagnosis patient group than the early diagnosed patient group (p=0.001, p=0.003, p=0.001), respectively. We also confirmed this positive relationship between delayed diagnosis and the HADS scores with Spearman`s correlation analysis.

Conclusion: We demonstrated that psychiatric disorders such as anxiety and depression are common in PAD patients, and delayed diagnosis strongly affects their anxiety and depression. Collaboration with psychologists and psychiatrists during the management of these patients may improve the quality of their life.