Prevalence and Assessment of Depression among Diffuse Idiopathic Skeletal Hyperostosis (DISH) patients

Background: Depression is most frequent among physical illness. Diffuse Idiopathic Skeletal Hyperostosis is a condition in which several ligaments and entheses become ossified. Objectives: Assessment of depression and the severity of depression among patients with diffuse idiopathic skeletal hyperostosis, and detection of risk factors. Methods: patients with diffusive idiopathic skeletal hyperostosis, both genders who have consulted during the study period and given their consent were assessed through sociodemographic and clinical data collection, and PHQ-9 questionnaire for depressive disorders evaluation. Results: The study investigates 43 patients with diffuse idiopathic skeletal hyperostosis. Prevalence of depression was 62%. Almost 88.88% of them were moderate to severe depression. Depression significantly associated with age, gender, occupation, life events, and duration of illness. Conclusion: depression is high in patients with diffuse idiopathic skeletal hyperostosis. Age, gender, occupation, life events, and duration of illness consider as the significant risk factors.


Introduction
Diffuse idiopathic skeletal hyperostosis (DISH) is a common systemic condition, of prevalence nearly 10% in those aged >50 years [1]. DISH also called as Forestier's disease, described firstly in 1950 by Rotes-Querol and Forestier. DISH is systemic idiopathic disease affecting the axial skeleton characterized by anterolateral spinal ligaments ossification and formation of osteophyte along the whole spines [2]. Decreased mobility and mild backache may be the results of ossification of many ligaments [3]. Thoracic spine usually affected by the disorder. Other joints and spines may be affected. Treatment and diagnosis usually delayed because the majority of patients were asymptomatic [4]. The pathogenesis of DISH was not clear, but other factors like; anatomic, endocrine, metabolic, genetic, toxic, and environmental factors may take part [5]. DISH is a disorder of old age, predominantly males male/female ratios 2:1-7:1 [6]. Physical illness induced mental illnesses usually disturbing to volition, personality disorder, and dementia. Mood disorders were accompanied physical illness, and most frequent is depression. Depression comorbid with physical disorders can be reactive or psychogenic inducted by social situation changes or depression directly results from the medical condition [7]. Characteristic features of depression include loss of interest, sadness, low self-esteem, feelings of guilt, sleep disturbance, changed appetite, poor concentration and tiredness. Depression may be long-lasting cores or recurrent episodes, with impairment of person's daily life function, work and school. Severe depression may end with suicide [8]. Depression diagnosis needs experience and accurate evaluation. Clinical practice and research purposes required tools for screening of depression. Many screening questionnaires are available, with different score thresholds to diagnose depression [9]. The Patient Health Questionnaire 9 (PHQ-9) is valid brief questionnaire [10] that used DSM-IV criteria for diagnosis of depression [11]. PHQ-9 can be self-rated, or interviewer-rated and is well validated dual-purpose questionnaire in the US that gives picture of This article is available in: http://clinical-psychiatry.imedpub.com/archive.php

Clinical Psychiatry
ISSN 2471-9854 depression severity [12], and DSM-IV diagnoses of depressive disorders: major depressive disorder, other depressive disorder and any depressive disorder. Validity of PHQ-9 was done in many countries in view of construct validity, diagnostic accuracy [13], changes sensitivity, responsiveness to treatment [14], internal consistency, test-retest reliability [15] and realistic estimates of population base rates [16].
Assessment of depression and the severity of depression among patients with diffuse idiopathic skeletal hyperostosis, and analysis of the significant sociodemographic and clinical risk factors associated with diffuse idiopathic skeletal hyperostosis patients were the aims of this study.

Design and setting
The current is a cross-sectional study. It was conducted from February 1st, 2015 to 31st August 2018, in the Psychiatry department with cooperation with Rheumatology unit at Imamain Kadhimain Medical City, Baghdad, Iraq.

Study population
All patients with diffusive idiopathic skeletal hyperostosis (DISH), both genders who have consulted within the time of study and given their agreement to participate were included.

Data collection tools
Questionnaires were filled by consultant psychiatrist, which included; the collection of sociodemographic and clinical data and PHQ-9 scale. The diagnosis of diffusive idiopathic skeletal hyperostosis (DISH) was based on the clinical findings, radiographic, and biological arguments. The study used the Arabic version of PHQ-9 to identify depression. Face validity process and internal consistency reliability was measured using Cronbach's alpha for the PHQ9, the results was 0.857 [17]. Patient Health Questionnaire (PHQ) is a clinical diagnostic tool that is widely utilized worldwide because it provides a practical in clinic tool to screen for psychological disorders. A PHQ-9 score ≥ 10 has a sensitivity of 88% and a specificity of 88% for major depression [13]. Major depressive disorder diagnosed if five or more of the nine criteria of depression have been elicited more than half of the days in the past two weeks and one of the symptoms is depressed mood or anhedonia [13]. PHQ-9 severity score from 0 to 27, since each item of the nine items can be scored from 0-3.

Statistical analysis
Analysis and processing of data was done using the SPSS version 20 software IBM system. Frequency and percentages were used. Depression prevalence was calculated. P value of <0.05 was considered for statistical significant.

Definition of variables
The independent variables evaluated to explain depression were Sociodemographic and clinical data include; age, gender, marital status, occupation, education, family history of mental illness, traumatic life events, and medical comorbidity. PHQ-9 used for evaluation and assessment of depression.

Ethical issues
After clarifying the aims of this study, informed consent and agreement were getting from each patient. Interviews were carried out with full privacy. Names and other details were kept anonymous.

Results
The current study includes total 52 diffuse idiopathic skeletal hyperostosis (DISH) patients. Nine of them not complete the questionnaire and withdrawn from the study. Data analysis was done for 43 patients. The age range was 45-80 years, mean 58 ± 9.6 years. About 80% fall into the age group ≥50 years. Male was nearly three forth of the sample; 86% married, about 72%of higher education, 60% still active working, non-smokers 72%. Patients with DISH exposed to life events 53.5%, patients with family history positive of mental illness were 11.6%, and about 35% have medical comorbidity ( Table 1).
The correlation of depression was statistically significant with duration of illness (P=0.030). The correlation of severity of depression was statistically significant with duration of illness (P=0.023) ( Table 5).

Discussion
This is the first study explores depression among diffuse idiopathic skeletal hyperostosis (DISH) patients. The mechanisms behind physical disorders elevate the risk of initiation of depressive disorder were two mechanisms. The first has cognitive or psychological mechanism. Chronic difficulty or life events may induce depressive disorder in susceptible patients. Second mechanism, more specific relation appears     [23,24]. There is association of depression with different disorders that presented with somatic or physical symptom, include, fibromyalgia, chronic fatigue and chronic pain states [19].
In conclusion depression is high in diffuse idiopathic skeletal hyperostosis (DISH) patients. Age, gender, occupation, life events, and duration of illness consider as the significant risk factors. Patients may get benefit from close liaison between mental health professionals and rheumatologist.