diabetes is the most common metabolic disease , with an increasing prevalence that reduces life expectancy to a third ( 1 , 2 ) .
there are 200 million people with diabetes worldwide ( about 5% of adult population ) ( 3 ) . according to a nationwide study in 2001 ,
the prevalence of diabetes in iran was estimated at 4.67% among the population older than 20 years ( 4 ) .
diabetes is usually associated with short - term complications such as hypoglycemia , and long - term complications like cardiovascular diseases , neuropathy , nephropathy , and retinopathy . amid
patients with diabetes are twice exposed to the risk of psychiatric diseases compared to normal population , and according to some studies , one in every 5 patients with diabetes suffer from depression ( 5 , 6 ) .
symptoms of depression were observed in 29% of men and 30.5% of women with diabetes in bangladesh villages ( 7 ) . in khamseh
study , 71.8% of patients with diabetes had major depression ( 8) , and in sepehrmanesh study in kashan , this rate was 57.7% among women and 41% among men ( 9 ) .
many factors can be affected by treatment of the disease , including physical function and daily activity , social relationships , quality of life , and personal mood .
as the disease affects patient s self - confidence and increase his or her fear of worsening complications , the risk of psychiatric diseases increases ( 10 ) .
depression is associated with increased risk of high blood glucose , complications of diabetes , cardiovascular diseases , and possibly patient s reduced compliance too ( 11 - 14 ) . furthermore , diabetic patients with depression have greater burden of treatment costs and referrals than those patients without depression ( 15 ) .
various studies have shown that unlike normal people , patients with diabetes have lower quality of life , and this is much more pronounced in those suffering from complications of diabetes ; depression also has a significant effect on patients quality of life ( 16 - 18 ) . in a study in yazd ,
the mean score of quality of life in studied patients was 25.65 out of 60 , and in patients with complications like retinopathy or neuropathy , this score was lower compared to patients without these complications ( 19 ) .
comorbidity of depression and diabetes can have a cumulative effect on people s functions ( 20 ) .
diagnosis of depression in these patients is particularly important in order to reduce complications and improve quality of life .
li et al . reported that depression was not diagnosed in 45% of diabetic patients ( 21 ) .
depression leads to patient s noncompliance , blood glucose mismanagement , and other physical complications ( 11 , 19 , 22 ) .
ciechanowski et al . reported that depressed patients are unable to comply with dietary regimen or manage blood glucose , and in this respect , they are clearly different from non - depressed patients ( 23 ) . with regard to the effect of diabetes with depression on the quality of life , in 2004 , filakovic et al . demonstrated that comorbidity of depression with diabetes further lowers patients quality of life by many folds ( 24 )
although several studies have been conducted on either quality of life or depression in diabetic patients , there are few studies on the relationship between quality of life and depression in diabetic patients .
moreover , given that failure to diagnose depression in diabetic patients is commonplace , the need to identify and screen psychiatric disorders in patients with chronic diseases , especially diabetes , and the impact of depression on the quality of life , this article aimed to investigate the relationship between depression and quality of life in patients with diabetes using medical records at diabetics clinic in gorgan .
the current survey was approved in the 46 ethics committee of golestan university of medical sciences ( no . 327123847 ) . in total
, 330 eligible patients with diabetes were selected from patients admitted to the only specialized diabetic clinic in city of gorgan , north of iran , at 5th azar hospital , in the first 6 months of 2012 .
inclusion criteria were confirmed diabetic record by the clinic specialist , age range of 25 - 75 years , having regular visits to the clinic , being under treatment with insulin and oral medication , not having type i diabetes , and not being treated for psychological health problems .
patients were assured of the confidentiality of data and their informed consents were obtained . according to ethics committee guidelines ,
study ( 25 ) , the correlation between the depression and quality of life ( r = 0.39 ) , 95% confidence interval , and 90% power test , 66 diabetic patients with depression were needed . to achieve that and with respect to 20% estimation of depression in patients with diabetes ( 5 , 7 ) , 330 patients with type 2
diabetes clinic is the only specialized and state referral clinic in gorgan that is supported by 5th azar hospital and is also one of the 3 state hospitals belonged to the golestan university of medical sciences . since more than 80% of attended patients with diabetes to the health centers , had been visited by the aforementioned clinic ( with continuous access ) and according to the all patients with record ( n = 1150 ) , 330 subjects were finally selected using systematic sampling with an interval of 3 ( k = n
/ n = 3 ) , in the way that the first patient was randomly selected .
then , a number was selected from 1 to 3 ( the second patient was selected ) . in other cases and with respect to the sampling interval as 3 , other samples were included ( such as number 5 , 8 to 989 ) .
demographic questionnaire was completed in the presence of patients , and related data to the disease and its complications were obtained from their records .
beck depression inventory ( bdi ) was used to assess depression , and the short version ( 26 items ) of the world health organization quality of life questionnaire ( whoqol - bref ) was used to assess quality of life .
bdi contains 21 items , which evaluates signs of depression , including sadness , guilt , loss of interest , social isolation , and suicidal ideation .
each item has rated on a 4-point likert scoring style from 0 for the lowest to 3 for the highest .
each option is determined from mild to severe ( 0 for psychological health , and scores 1 , 2 , and 3 for mild , moderate , and severe disorders , respectively ) .
overall depression score for each patient is found by summing up scores of all items , ranging from 0 to 63 , and higher scores indicate more severe depression , as follows : 0 to 15 means no depression , 16 to 31 mild depression , 32 to 47 moderate depression , and 48 to 63 severe depression .
its reliability was determined through internal consistency using cronbach  of 84% , and correlation was obtained 70% using split half method ( 26 ) . in this study ,
cronbach  for the reliability of questionnaire for diabetic patients was found 0.77 , which indicates the questionnaire was suitable for this study .
diez - quevedo et al . also studied it in diagnosing mental disorders in 1003 general hospital spanish inpatients in 2001 ( 27 ) . in the 26-item whoqol - bref ,
the first two items assess general health status and quality of life , and the next 24 items assess quality of life in 4 domains of physical health , psychological health , social relationships , and environment using 3 , 6 , 7 and 8 items , respectively . in this study
the 5-point likert scale was applied for items 1 and 15 ( very bad , bad , not bad , good , and very good ) , items 2 , and 16 to 25 ( very unhappy , unhappy , not unhappy , happy , and very happy ) , items 3 to 14 ( not at all , a little , medium , high , and very high ) , and for item 26 ( never , rarely , occasionally , often , and always ) . scoring for items 3 , 4 , and 26 was in reverse . to compare domains and the first two items in depressed and non - depressed groups of patients , quality of life score for each patient ( xi )
was converted into scores between 0 and 100 using the following equation 2 ( 28 - 31 ) : validity and reliability of whoqol - bref have been reported favorable in many native and foreign studies ( 17 , 30 , 32 ) . in the present study ,
validity of this questionnaire was estimated according to internal consistency for the whole scale of 85% , physical health 78% , psychological health 80% , social relationships 69% , and environment 84% .
the normality of qol scores and its dimensions were tested and confirmed by kolmogorov - smirnov test .
where an item was missing , we substituted the mean of other items in the domain .
also , when more than 2 items were missing from a domain , we did not calculate the domain score .
the missing data in bdi questionnaire were replaced using median near points . to describe data , central and dispersion indicators such as mean and standard deviation were calculated . to compare qualitative characteristics of depressed and non - depressed patients , chi - square test was used .
mean scores of qol and its sub - domains , age , and duration of disease in two groups were analyzed using independent t test .
we conducted multiple linear regression analyses to assess prediction of qol scores and its relationship with other variables .
in addition , we used scatter diagrams to visualize the relationship between dependent variable and each metric independent variable to be sure that they are linear .
in addition , we also checked whether the relationship between dependent variable and categorical independent variables is homoscedastic .
the current survey was approved in the 46 ethics committee of golestan university of medical sciences ( no . 327123847 ) .
in total , 330 eligible patients with diabetes were selected from patients admitted to the only specialized diabetic clinic in city of gorgan , north of iran , at 5th azar hospital , in the first 6 months of 2012 .
inclusion criteria were confirmed diabetic record by the clinic specialist , age range of 25 - 75 years , having regular visits to the clinic , being under treatment with insulin and oral medication , not having type i diabetes , and not being treated for psychological health problems .
patients were assured of the confidentiality of data and their informed consents were obtained . according to ethics committee guidelines ,
study ( 25 ) , the correlation between the depression and quality of life ( r = 0.39 ) , 95% confidence interval , and 90% power test , 66 diabetic patients with depression were needed . to achieve that and with respect to 20% estimation of depression in patients with diabetes ( 5 , 7 ) , 330 patients with type 2
diabetes clinic is the only specialized and state referral clinic in gorgan that is supported by 5th azar hospital and is also one of the 3 state hospitals belonged to the golestan university of medical sciences . since more than 80% of attended patients with diabetes to the health centers , had been visited by the aforementioned clinic ( with continuous access ) and according to the all patients with record ( n = 1150 ) , 330 subjects were finally selected using systematic sampling with an interval of 3 ( k = n
/ n = 3 ) , in the way that the first patient was randomly selected .
then , a number was selected from 1 to 3 ( the second patient was selected ) .
in other cases and with respect to the sampling interval as 3 , other samples were included ( such as number 5 , 8 to 989 ) .
demographic questionnaire was completed in the presence of patients , and related data to the disease and its complications were obtained from their records .
beck depression inventory ( bdi ) was used to assess depression , and the short version ( 26 items ) of the world health organization quality of life questionnaire ( whoqol - bref ) was used to assess quality of life .
bdi contains 21 items , which evaluates signs of depression , including sadness , guilt , loss of interest , social isolation , and suicidal ideation .
each item has rated on a 4-point likert scoring style from 0 for the lowest to 3 for the highest .
each option is determined from mild to severe ( 0 for psychological health , and scores 1 , 2 , and 3 for mild , moderate , and severe disorders , respectively ) .
overall depression score for each patient is found by summing up scores of all items , ranging from 0 to 63 , and higher scores indicate more severe depression , as follows : 0 to 15 means no depression , 16 to 31 mild depression , 32 to 47 moderate depression , and 48 to 63 severe depression .
its reliability was determined through internal consistency using cronbach  of 84% , and correlation was obtained 70% using split half method ( 26 ) . in this study ,
cronbach  for the reliability of questionnaire for diabetic patients was found 0.77 , which indicates the questionnaire was suitable for this study .
diez - quevedo et al . also studied it in diagnosing mental disorders in 1003 general hospital spanish inpatients in 2001 ( 27 ) . in the 26-item whoqol - bref ,
the first two items assess general health status and quality of life , and the next 24 items assess quality of life in 4 domains of physical health , psychological health , social relationships , and environment using 3 , 6 , 7 and 8 items , respectively . in this study
the 5-point likert scale was applied for items 1 and 15 ( very bad , bad , not bad , good , and very good ) , items 2 , and 16 to 25 ( very unhappy , unhappy , not unhappy , happy , and very happy ) , items 3 to 14 ( not at all , a little , medium , high , and very high ) , and for item 26 ( never , rarely , occasionally , often , and always ) . scoring for items 3 , 4 , and 26 was in reverse . to compare domains and the first two items in depressed and non - depressed groups of patients , quality of life score for each patient ( xi )
was converted into scores between 0 and 100 using the following equation 2 ( 28 - 31 ) : validity and reliability of whoqol - bref have been reported favorable in many native and foreign studies ( 17 , 30 , 32 ) . in the present study ,
validity of this questionnaire was estimated according to internal consistency for the whole scale of 85% , physical health 78% , psychological health 80% , social relationships 69% , and environment 84% .
the normality of qol scores and its dimensions were tested and confirmed by kolmogorov - smirnov test .
where an item was missing , we substituted the mean of other items in the domain .
also , when more than 2 items were missing from a domain , we did not calculate the domain score .
the missing data in bdi questionnaire were replaced using median near points . to describe data , central and dispersion indicators such as mean and standard deviation were calculated . to compare qualitative characteristics of depressed and non - depressed patients , chi - square test was used .
mean scores of qol and its sub - domains , age , and duration of disease in two groups were analyzed using independent t test .
we conducted multiple linear regression analyses to assess prediction of qol scores and its relationship with other variables .
in addition , we used scatter diagrams to visualize the relationship between dependent variable and each metric independent variable to be sure that they are linear .
in addition , we also checked whether the relationship between dependent variable and categorical independent variables is homoscedastic .
a total of 330 diabetic patients ( 35.5% men , and 64.5% women ) were studied , with mean and standard deviation of age and history of disease of 50.6  9 and 5.4  4.5 years , respectively , and age range of 25 to 75 years .
the prevalence of depression in all diabetic patients was 58.2% , of whom 124 patients ( 64.6% ) had mild depression , 56 ( 29.2% ) moderate depression , and 12 ( 6.2% ) severe depression .
this was in 64.8% of men and 61.5% of women , with insignificant differences between them .
depression was observed in 45.1% of the single diabetic patients and in 60.6% of married ones , with significant difference ( p = 0.039 ) .
more than 50% of depressed diabetic patients and 62.5% of non - depressed diabetic patients were literate , and the difference between two groups was significant .
however , there were insignificant differences between the two groups in terms of employment status ( table 1 ) .  
( % ) . mean and standard deviation of depression score according to bdi was 29.4  10.1 in depressed patients , and 8.1  4.1 in non - depressed patients , with a significant difference between them ( p < 0.001 ) .
comparison of the relationship between clinical characteristics and depression in patients with diabetes showed insignificant differences between the two groups with respect to dietary regimen , diabetes complications ( retinopathy , neuropathy , and nephropathy ) , and duration of the disease .
however , hypertension was 13.9% more ( p < 0.001 ) , and physical activity 24.7% less in diabetic patients with depression , and the difference between groups was significant ( p = 0.01 ) ( table 2 ) .  
comparing scores of various domains of quality of life between depressed and non - depressed patients with diabetes using independent t test indicated significant lower mean scores in subscales of general health , quality of life in general , psychological health , environment , and overall score of quality of life in depressed diabetic patients at error level of 0.001 .
however , in physical health domain , mean score was lower in depressed patients , with a significant difference ( p = 0.009 ) ( table 3 ) .  
linear regression model of prediction of quality of life score with independent variables of age , gender , duration of disease , hypertension , diabetes complications , education , marital status , occupation , physical activity , and depression score showed significant and inverse relationship between overall score of quality of life and variables of physical activity , diabetes complications or otherwise , and depression score ( p = 0.01 ) ( table 4 ) .
the present study results are in line with the results in other studies , and suggest high prevalence of depression among patients with diabetes ( 7 - 9 , 19 ) . according to the present study ,
58.2% of participants had moderate to severe depression and 15.5% had mild depression , i.e. , 73.7% of the patients are likely to have depression . in a study by nedjat et al .
( 28 ) , 28% of patients were depressed and 38% had mild depression , making a total of 66% .
the rate of depression was 41.9% in larijani , and 53.3% in sepehrmanesh studies ( 9 , 19 , 21 ) .
kahn et al . argue that not only depression could result from diabetes ; but also it is a risk factor for the onset of diabetes ( 22 ) .
depression is associated with 60% increased risk of type 2 diabetes , while diabetes only causes an increased risk of depression by about 15% ( 23 ) .
however , in the present study , there was an insignificant difference between sexes in the prevalence of depression , which is in line with results of pinquart et al .
the mean overall quality of life score in depressed patients was 50.68  14.04 , which was significantly lower than non - depressed patients with 60.46  13.27 , and is close to the results found by nedjat et al .
( 28 ) . in psychiatric and habitat areas and overall score , the differences between groups was significant , and among depressed patients , mean score was lower , which is in line with other studies ( 6 , 25 , 28 ) . only in social relationships domain , the difference between the two groups was insignificant .
perhaps , it could be attributed to rich relationships between patients and their family and relatives , which often become richer at times of disease .
depression can affect physical outcomes such as myocardial infarction , life expectancy in cancer patients , and infections . also , it explains the effect of depression on immune system the most .
other reasons for this effect can be due to the fact that depression in diabetic patients affects compliance , proper dietary regimen , smoking , and exercise ( 7 ) . in a study by lin et al . , it was confirmed that depressed patients perform more poorly than other patients in compliance with personal care , including proper nutrition , exercise , compliance with treatment and prevention ( 34 ) . in another study
it was found that regarding incident disability and mortality , the effects of interaction between diabetes and depression seemed to be synergistic ( that is , greater than the additive main effects of diabetes and depression ) .
compared depressed patients and 8 groups of patients with chronic diseases , and found that depressed patients showed greater reduction in the quality of life than the other 8 groups , and this effect remained , even after eliminating factors such as age , gender , and chronic diseases ( 35 ) . in the present study ,
high prevalence of comorbidity of depression with diabetes in patients indicates that effect of depression comorbidity on the quality of life can significantly affect outcomes of the disease , and early diagnosis of depression can improve quality of life ( 25 ) .
study limitations included lack of measurement of hba1c , which could help assess better the patients blood glucose , and its effect on disease complications .
it is , therefore , suggested that its measurement be taken into consideration in future similar studies . given the results of this and other studies , it seems that there is high prevalence of depression among patients with diabetes , and it has a significant effect on diabetes outcomes and quality of life .
it is recommended that besides regular doctors visits in terms of physical problems , the psychiatric problems and quality of life of these patients should also be more considered .
regular psychiatrist visits , or psychological assessments for screening mental disorders can help early diagnosis of these disorders .
our survey weaknesses were as follow : 1 ) we used self - administered questionnaire , which could include patients bias , 2 ) participants may not have fully understood or have misinterpreted questions that might have biased the responses , and 3 ) we conducted a cross - sectional method that provided us with information for that particular issue in time .
however , our study strong points can be mentioned as covering more than 80% of patients with diabetes in golestan province who were attended to the only specialized diabetes clinic supported by golestan university of medical sciences .
 background : frequency of mood disorders in patients with chronic diseases , especially diabetes and its effects on life quality are dramatically increasing.objectives:this study aimed to investigate the relation between depression and quality of life in patients with diabetes.patients and methods : this is a cross sectional survey . 
 subjects were selected from 330 eligible people referred to the only diabetes clinic in gorgan city during 6 months , using systematic random sampling . 
 beak depression questionnaire and the brief questioner with 26 questions recommended by the world health organization ( whoqol - bref ) were used to measure depression and quality of life , respectively . 
 data were analyzed through descriptive methods , chi - square , independent t test and linear regression model using spss16 ; moreover , p value < 0.05 was considered as significant.results:in total , 330 patients with diabetes ( 35.5 % male and 64.5% women ) were studied . 
 the mean and standard deviation of their age and years involved with diabetes were 50.6  9.0 and 5.4  4.5 years , respectively . 
 range of age was 25 - 75 years , as well . 
 the prevalence of depression in all patients with diabetes was 58.2% ( 124 mild , 56 medium , and 12 with severe depression ) . 
 hypertension was 13.9% more in diabetic patients with depression ( p value < 0.001 ) and physical activity in 24.7% of the cases was less with a meaningful difference ( p value = 0.01 ) . 
 the mean and standard deviation of quality of life in diabetic patients with and without depression was 50.7  14 and 60.5  13.3 , respectively that was significant in two groups ( p < 0.0001).conclusions : the prevalence of depression is high in patients with diabetes and has a considerable impact on the consequences of diabetes and quality of life too . 
1. Background
2. Objectives
3. Patients and Methods
3.1. Study Design
3.2. Participants
3.3. Sample Size
3.4. Sample Frame
3.5. Instrument
3.6. Data Analysis
4. Results
5. Discussion