stroke patients experience depression and a decrease in the overall quality of life ( qol ) 
 due to long - term disability and loss of motor and cognitive functions from brain damage1 . the qol of stroke is a comprehensive index 
 of stroke recovery comprising physical , psychological , emotional , and social aspects of 
 recovery2 . furthermore , it is difficult 
 to recruit patients who are depressed as their willingness to be involved decreases3 . transcranial direct current stimulation 
 ( tdcs ) is one of the most convenient and safe rehabilitation methods designed for patients 
 with stroke , as it allows changes in brain plasticity through direct stimulation of the 
 brain4 . when tdcs is administered in 
 patients with stroke , they show improvements in hand function , sense of balance , lower limb 
 function , kinesthesis , visual perception ability , and activities of daily living ( adl)5,6,7 . however , no previous study has investigated 
 depression , which is an important psychosocial factor that must be addressed during recovery 
 from stroke . . therefore , the 
 present study aims to investigate how tdcs influences the qol and the overall psychosocial 
 health of stroke survivors . the patients recruited to this study were diagnosed by computed tomography ( ct ) or magnetic 
 resonance imaging ( mri ) , and were admitted to the m rehabilitation center in busan for four 
 weeks between january and march 2016 . this study was conducted in accordance with the 
 declaration of helsinki and was approved by the kaya university institutional review board 
 ( kaya irb-145 ) . the final group of participants consisted of patients who were confirmed to 
 be severely depressed ( as evidenced by a score above 16 on the beck depression inventory ) , 
 understood the purpose of our study , and provided their written consent . the 40 patients 
 selected based on these criteria were divided into two groups ( containing 20 patients each ) : 
 an experimental group that would receive conventional occupational therapy and tdcs , and a 
 control group that would receive conventional occupational therapy and false tdcs . the 
 participants were divided according to their order of admission , such that patients with an 
 odd admission number were assigned to the control group , while patients with an even 
 admission number were assigned to the experimental group . the tdcs protocol involved 
 generating a direct current using fda - approved batteries ( phoresor pm 850 
 ( phoresor ii auto model no . pm 850 , iomed , inc . , salt lake city , usa ) ) . 
 according to the international 1020 system , the anode was wrapped in straps and attached to 
 the left dorsolateral prefrontal cortex ( dlpfc ) , while the cathode was attached in the same 
 manner to the right dlpfc8 . the 
 experimental group received tdcs applied at 2 ma 20 times over the course of four weeks 
 ( five times a week ) , for 30 minutes during each session based on the stability study by 
 bueno et al.8 . in the control group , the 
 anode and cathode positions were the same as in the experimental group ; however , the 
 stimulation was stopped 30 seconds after the application without letting the participants 
 know until 30 minutes elapsed . this study targeted 
 patients with severe depression ( bdi scores of 16 and higher ) . the stroke - specific quality 
 of life ( ss - qol ) developed by williams et al.10 was used to investigate qol11 . the mean and standard deviation of all scores in the two groups 
 were calculated using descriptive statistics . the difference between scores measured before 
 and after treatment was determined using a paired t - test . the experimental group consisted of 17 men and 3 women , while the control group consisted 
 of 13 men and 7 women . the experimental group had 13 patients with left paralysis ( and 7 
 with right paralysis ) , while control group had 5 patients with left paralysis ( and 15 with 
 right paralysis ) . the mean age ( in years ) of the patients in the experimental and control 
 groups was 51.0  11.7 and 62.4  12.4 , respectively . as for the disease duration , the 
 experimental group consisted of 9 patients who had stroke for 712 months , 7 patients who 
 had stroke for 1324 months , and 4 patients who had stroke for over 24 months ; while the 
 control group consisted of 8 patients who had stroke for 712 months , 8 patients who had 
 stroke for 1324 months , and 4 patients who had stroke for over 24 months . homogeneity tests 
 conducted on the general characteristics of patients from the two groups revealed no 
 significant between - group differences ( p>0.05 ) ( table 1table 1.the general characteristics of the subjects ( n=40)categoriesitemsexperimental groupcontrol groupn%n%gendermale1785.01365.0female315.0735.0age ( years)51.0  11.762.4  12.4paretic sideleft1365.0525.0right735.01575.0time since stroke ( month)14.6  6.314.7  5.9cause of diseasecerebral infarction1155.01260.0cerebral hemorrhage945.0840.0 ) . the depression level of patients in the experimental group significantly 
 decreased from 38.8  4.7 ( before tdcs ) to 16.8  4.6 ( after tdcs ) . the depression level of 
 patients in the control group also decreased from 39.0  4.6 ( before false tdcs ) to 37.8  
 6.1 ( after false tdcs ) ; however , this difference was not statistically significant . the qol 
 measured through ss - qol significantly increased in the experimental group from 152.1  16.9 
 ( before tdcs ) to 167.7  25.7 ( after tdcs ) . the qol also increased in the control group from 
 154.3  18.3 ( before false tdcs ) to 162.1  18.7 ( after false tdcs ) ; however , this 
 difference was not statistically significant ( table 
 2table 2.comparison of the changes in depression and qolexperimental groupcontrol grouppre - test ( mean  sd)post - test ( mean  sd)pre - test ( mean  sd)post - test ( mean  sd)depression38.8  4.716.8  4.6 * 39.0  4.637.8  6.1qol152.1  16.9167.6  25.7 * 154.3 our results reveal that tdcs intervention caused a significant decrease in depression 
 levels in the experimental group . the anode stimulation is known to increase the 
 excitability of cerebral cortex and enhance awareness , while the cathode stimulation is 
 known to suppress the excitability of the cerebral cortex and make the subject quieter and 
 passive12 . based on these observations , 
 it can be assumed that the decrease in depression levels was caused by the enhancement of 
 awareness resulting from the increase in brain activity in patients with stroke . our 
 findings are in line with those observed by valiengo et al.13 , who used 10 applications of tdcs to the dlpfc of 23 stroke 
 survivors with aphasia , and found that their depressive symptoms decreased after four weeks . in addition to the improvement in depression symptoms , our study found a significant 
 increase in the qol of the experimental group . this result is similar to that of the study 
 by viana et al.14 , in which an 
 experimental group ( n=10 ) received virtual reality therapy ( vrt ) as well as tdcs , while the 
 control group ( n=10 ) received vrt and false tdcs . the authors reported significant 
 improvement in the qol as well as upper limb function in the experimental group . our study 
 is significant as it confirms that tdcs , a method to increase brain plasticity in patients 
 with decreased qol , improves depression and qol in stroke survivors with depression . moreover , our results indicate that tdcs can be effectively applied in the patients 
 depression treatment in order to improve their qol . this study has two limitations : 1 ) the 
 results are difficult to generalize due to the small sample size , and 2 ) other factors 
 influencing qol have not been investigated . therefore , future studies should investigate a 
 larger number patient in order to allow generalization of the results , and conduct 
 continuous research on depression and improvement in qol in patients with stroke .
[ purpose ] the aim of this study was to assess the effects of transcranial direct current 
 stimulation ( tdcs ) on depression and quality of life ( qol ) in patients with stroke , by 
 conducting conventional occupational therapy with and without tdcs on 20 patients each . 
 [ subjects and methods ] the experimental group ( n=20 ) received both tdcs and conventional 
 occupational therapy , while the control group ( n=20 ) received false tdcs and conventional 
 occupational therapy . 
 the treatment was conducted 20 times over a four - week period ; each 
 session was 30 minutes long . 
 the beck depression inventory ( bdi ) was administered to score 
 the depression levels in patients before and after the intervention , while the 
 stroke - specific quality of life ( ss - qol ) was measured to compare the qol . 
 [ result ] 
 following the intervention , the patients in the experimental group showed a significant 
 decrease in depression and an increase in the qol . 
 in contrast , the control group showed 
 no significant changes in depression or qol . 
 our findings indicate that tdcs decreased 
 depression while increasing qol in patients with stroke . 
 [ conclusion ] in other words , our 
 study confirmed that the application of tdcs during stroke rehabilitation improves the 
 depression symptoms and qol in patients .