increased rate of depression among individuals with rheumatoid arthritis ( ra ) in comparison with the general population has been described previously ( 1 , 2 ) .
it has also been shown that depression can be associated with reduced health - related quality of life ( 3 ) and weakness ( 4 ) in patients with ra , which leads to poorer long - term outcomes ( 5 ) .
it is essential to target and treat depression since increased mortality rate has been reported in depressed subjects with ra ( 6 ) .
although the association between depression and ra has been demonstrated in previous studies , there are conflicting results in the prevalence of depression in ra .
since there are various factors that affect incidence of depression , including socioeconomics condition and familial support , observing different prevalence rates among different nations can be expected . until now
, no investigation has been performed to estimate the prevalence of depression among iranian patients with ra . before implementation of any kind of intervention to target depression , it is essential to know the background condition and prevalence of depression in a specific population .
the reported estimation of depression prevalence in ra has a wide range from 9.5%   to 41.5% ( 7 ) .
therefore , it is necessary to estimate the prevalence of depression in each population separately . to understand the impact of depression on ra .
rheumatoid arthritis is a chronic multifactorial inflammatory disease , which primarily affects joints ( 8) and is associated with pain and weakness .
it is characterized by joint swelling , morning stiffness and disability ( 9 ) . since ra is a chronic condition ,
it should be taken into consideration that cumulative risk of depression and also intermittent recurrences can occur ( 10 , 11 ) .
another reason for existence of conflicting reports in prevalence of depression in ra is the usage of different assessment tools ( 1 ) .
prevalence of depression has been reported much higher in studies using self - report measures ( 12 ) . however , a higher rate of depression among patients with ra has been often observed in comparison with the general population ( 13 ) .
the aim of this study was to evaluate the prevalence of depression among iranian patients with ra using beck s depression inventory ii ( bdi ii ) , and to compare it with healthy subjects .
the effect of pain , weakness and rheumatoid factor ( rf ) status on depression was also assessed .
we investigated patients with ra , who were referred to rheumatology clinics of kermanshah university of medical sciences in a descriptive cross - sectional study .
the study was approved by the research ethics committee of kermanshah university of medical sciences .
patients with ra , who were referred to rheumatology clinics , were entered in this study .
exclusion criteria were : previous history of other chronic diseases ( such as diabetes , hypertension , collagen vascular disorders , hypo - or hyperthyroidism , metabolic disorders , and etc . ) , addiction to illegal drugs , and smoking and alcohol consumption .
the sampling method was based on selection of participants according to the inclusion and exclusion criteria .
age , marital status , educational level and occupation were asked directly from the participants and were indexed in pre - prepared forms .
existence of pain and weakness was assessed subjectively by patients self - report to yes / no questions .
beck s depression inventory ii is a self - report measurement for depression , which consists of 21 items in two subscales ( 14 ) .
each of the 21 items corresponds to a symptom of depression and is summed to give a single score for bdi ii .
there is a four - point scale for each item ranging from 0 to 3 . on two items ( 16 and 18 )
there are seven options to indicate either an increase or decrease of appetite and sleep .
total score of 0 - 13 is considered in the minimal range , 14 - 19 indicates mild depression , 20 - 28 shows moderate , and 29 - 63 illustrates severe depression .
the persian version of this questionnaire has been validated and its high internal consistency ( cronbach s alpha = 0.87 ) and validity ( r = 0.74 ) have been demonstrated ( 15 ) .
all statistical analysis was performed using spss software version 18 ( spss , inc . ,
categorical variables were expressed with frequency , and continuous variables were described with mean standard deviation .
chi - square test was used to compare prevalence of depression between the two groups .
comparison of means was performed using independent t - test and one - way analysis of variances ( anova ) .
we investigated patients with ra , who were referred to rheumatology clinics of kermanshah university of medical sciences in a descriptive cross - sectional study .
the study was approved by the research ethics committee of kermanshah university of medical sciences .
patients with ra , who were referred to rheumatology clinics , were entered in this study .
exclusion criteria were : previous history of other chronic diseases ( such as diabetes , hypertension , collagen vascular disorders , hypo - or hyperthyroidism , metabolic disorders , and etc . ) , addiction to illegal drugs , and smoking and alcohol consumption .
the sampling method was based on selection of participants according to the inclusion and exclusion criteria .
age , marital status , educational level and occupation were asked directly from the participants and were indexed in pre - prepared forms .
existence of pain and weakness was assessed subjectively by patients self - report to yes / no questions .
beck s depression inventory ii is a self - report measurement for depression , which consists of 21 items in two subscales ( 14 ) .
each of the 21 items corresponds to a symptom of depression and is summed to give a single score for bdi ii .
there is a four - point scale for each item ranging from 0 to 3 . on two items ( 16 and 18 )
there are seven options to indicate either an increase or decrease of appetite and sleep .
total score of 0 - 13 is considered in the minimal range , 14 - 19 indicates mild depression , 20 - 28 shows moderate , and 29 - 63 illustrates severe depression .
the persian version of this questionnaire has been validated and its high internal consistency ( cronbach s alpha = 0.87 ) and validity ( r = 0.74 ) have been demonstrated ( 15 ) .
all statistical analysis was performed using spss software version 18 ( spss , inc . ,
categorical variables were expressed with frequency , and continuous variables were described with mean standard deviation .
chi - square test was used to compare prevalence of depression between the two groups .
comparison of means was performed using independent t - test and one - way analysis of variances ( anova ) .
a total of 171 patients in the ra group and 198 subjects in the control group participated in this investigation .
mean age in ra and control group was 42.05  11.22 and 41.36  10.77 years old .
the majority of participants in both groups were female ( 123 ( 62.1% ) in the ra group and 108 ( 63.2% ) in the control group ) .
most subjects in both groups were also married ( 71.2% and 77.2% in the ra and control groups , respectively ) .
only 17.7% of patients in the ra group ( n : 35 ) and 19.9% of participants in the control group ( n : 34 ) were living in villages .
there were no significant differences in the demographic features between the two groups ( table 1 ) .
one hundred and three participants ( 52% ) in the control group and 30 patients ( 29.2% ) in the ra group had minimal range of bdi ii score whereas 29 patients in the ra group ( 17% ) and 20 healthy subjects ( 10.1% ) revealed severe depression ( table 1 ) . in the ra group , 45.7% of patients revealed some extent of depressive mood whereas this estimation was 32.8% in the control group ( p = 0.008 ) .
abbreviation : ns , not significant * significance at the level of p < 0.01 ; * * chi - square test was used to compare the prevalence of each category between groups .
mean bdi ii score was significantly higher in the ra group in comparison with the control group ( 15.53  11.04 and 19.26  10.06 in the control and ra groups , respectively ; p = 0.001 ) .
similar results were obtained when we compared the mean scores of bdi ii between each gender separately ( table 2 ) .
mean bdi ii score was 18.49 8.56 and 14.66  10.97 among males in ra and control group , respectively ( p = 0.026 ) .
similarly female participants in the ra group obtained higher scores than healthy subjects ( 19.71  10.85 and 16.05  11.09 in the ra and control groups , respectively ; p = 0.012 ) .
although there was a significant difference in bdi ii scores between these two groups among participants younger than 50 years old , patients with ra , who were older than 50 years showed significantly higher bdi ii scores in comparison with healthy subjects ( 21.11  9.36 and 16.48  11.6 in ra and control groups , respectively ; p = 0.036 ) ( table 2 ) . abbreviation : sd , standard deviation . * significance at the level of p < 0.05 ; * * independent t - test was used to compare means between groups .
severity of depression detected by bdi ii was significantly higher among males and females with ra .
minimal range of bdi ii score was detected in 34 females with ra ( 31.5% ) and 62 healthy females ( 50.4% ) , whereas 21 females with ra showed severe depression ( 19.43% ) while the prevalence of severe depression among healthy females was only 12 ( 9.75% ) ( p = 0.016 ) .
significance at the level of p < 0.05 ; * * significance at the level of p < 0.01 .
p - value stands for chi - square test to evaluate prevalence between categorical groups . in the ra group , 154 ( 90.1% ) mentioned that they were feelings of pain and only 17 patients ( 9.9% ) expressed having no pain .
similarly , 149 ( 87.2% ) felt weakness and 22 ( 12.8% ) did not complain from weakness .
no significant association was found between existence of pain and weakness and score of bdi ii ( p = 0.14 and 0.19 , respectively ) .
rheumatoid factor ( rf ) was positive in the majority of patients ( 87.7% ) .
positive rf status was associated with lower scores of bdi ii whereas patients with negative rf status were significantly more susceptible to severe depression ( p = 0.001 ) . among patients that had positive rf status , 33% had minimal ,
25% had mild , 28% had moderate and only 12.8% had severe depressive mood . among patients with negative rf status , 43% had severe depression and no case of minimal range of bdi ii
these results show that positive rf can be a preventive factor for depression among patients with ra .
in the present study , the prevalence of depression was assessed in patients with ra and was compared with a group of healthy subjects .
, we reported that 17% of iranian patients with ra had severe depression , which is significantly higher than healthy individuals .
higher level of mood deterioration in patients with ra in comparison with the general population has been reported , previously ( 1 , 2 ) .
the role of social support ( 16 ) and socioeconomic status ( 17 ) has been described by zyrianova et al .
( 17 ) , studies of whom demonstrated that higher rate of depression in ra is associated with lower socioeconomic status and social support , which insists on the fact that the prevalence of depression may vary in different countries in which patients receive different levels of social support . to the best of our knowledge ,
this is the first investigation assessing the prevalence and impact of depression among iranian patients with ra .
our study showed higher prevalence of depression and higher rate of severe depression among patients with ra regardless of gender .
however , older patients ( older than 50 years old ) showed more depressive signs than healthy subjects at a similar age , which is in line with the report of matcham et al . ( 1 ) . however , matcham also explained that this higher rate of depression in elderly might exist regardless of presence of ra , since increased risk of depression in the elderly has been described previously ( 18 ) . in this regard , our study showed that elderly patients with ra are more depressed than healthy subjects at a similar age .
in fact , old age , which is an independent determinant of depression , affects patients with ra more considerably than the normal population . in line with our results , dickens et al .
( 19 ) reported that depression is more common in patients with ra than in healthy individuals .
however , dickens proposed that this difference is not due to socio - demographic differences between groups . moreover in their meta - analysis the role of various methods of assessing depression in differences among studies , examining the levels of depression in patients with ra , was described . similarly , matcham et al .
( 1 ) showed that depressive symptoms were present in 38.8% of subjects using the patient health questionnaire phq-9 , and in 14.8% to 48% of subjects using the hospital anxiety and depression scale ( hads ) .
here we used the beck depression inventory ii to determine depression among patients with ra . according to our results
, 45% of patients with ra showed some extent of depressive mood ( 28% moderate and 17% severe depression ) .
the relative difference between our report and previous literature can be due to variations in the measurement tools .
( 21 ) demonstrated the role of disease acceptance in the association between pain and depression in ra .
their study illustrated that patients with higher acceptance had slower growth rates of depression across time , even when pain increased .
this finding showed that acceptance is a confounder in the correlation between pain and depression . here , we found no association between pain and bdi ii score , which may be due to the existence of such confounders .
previously , wolfe and michaud showed that weakness is a dominant predictor of self - reported depression in ra ( 10 ) .
one reason for these conflicting results can be differences in weakness of the measurement tool .
although all these investigations have assessed weakness through patients subjective self - report , variation in assessment tools can cause such conflicts in the outcomes .
age , duration of ra and existence of other comorbid conditions are probable confounders that may affect the linear relationship between weakness and depression in ra .
previously , tillmann et al . reported that the rf - subtype is associated with higher incidence of depression ( 23 ) , which is in line with our results .
previous literature has linked rf negative status to the covariates of depression , such as psychiatric disorders anxiety and neuroticism ( 24 - 26 ) .
furthermore , rf negative status has been associated with lower self - acceptance , somatization complaints and obsessive - compulsiveness ( 27 , 28 ) .
all these studies , including our investigation , have proposed rf negative status as an available biomarker , which may be clinically linked to higher psychopathy . here , we found that depression is more common among iranian patients with ra than healthy subjects and is estimated to be 45% ( p = 0.008 ) .
the higher rate of depression exists among patients with ra regardless of gender but it has a significant association with older age ( p = 0.03 ) .
here , we found that depression is more common among iranian patients with ra than healthy subjects and is estimated to be 45% ( p = 0.008 ) .
the higher rate of depression exists among patients with ra regardless of gender but it has a significant association with older age ( p = 0.03 ) .
 backgroundincreased prevalence of depression among patients with rheumatoid arthritis ( ra ) has been described previously . however , the impact of depression among iranian patients has not yet been investigated.objectiveshere , the prevalence of depression was assessed and the effect of disease - related characteristics including pain , weakness and rheumatoid factor ( rf ) status on incidence of depression was evaluated.materials and methodspatients with ra , who were referred to rheumatology clinics of kermanshah university of medical sciences and healthy subjects from the general population of kermanshah participated in this investigation . 
 depression was assessed using beck s depression inventory ii ( bdi ii ) . 
 pain and weakness were assessed subjectively by patients self - report . 
 data was collected during a year between 2012 and 2013 . 
 chi - square test and independent t - test were used.resultsone hundred and seventy - one patients with ra and 198 healthy individuals participated in this investigation . in the ra group , 
 depressive mood was detected in 45.7% of patients , which was significantly higher than healthy subjects ( p = 0.008 ) . 
 depression was more common in elderly patients ( > 50 years old ) in comparison with healthy subjects at a similar age ( p = 0.03 ) . 
 pain and weakness had no influence on depression incidence ( p = 0.14 and 0.19 , respectively ) whereas patients with negative rf status were significantly more susceptible to severe depression ( p : 0.001).conclusionsdepression is more common among iranian patients with ra ( 45% ) than healthy subjects regardless of gender . 
 depression has a significant association with older age . 
 negative rf status may predict future risk of depression . 
1. Background
2. Objectives
3. Materials and Methods
3.1. Study Design
3.2. Participants
3.3. Becks Depression Inventory II (BDI II)
3.4. Statistical Analysis
4. Results
5. Discussion
5.1. Conclusion