Table1. Descriptive statistics of the research variables
The data included in table 1 shows The mean of TDCS (3.643), mean depression (3.515) and mean anxiety (3.623).
Testing the normality of the data distribution
In order to test the data normality, different method are used one of which is using the form of the distribution or in other words, calculating the skewness and kurtosis of the research variables. Researchers believe that whenever skewness and kurtosis of the data are between 2 and -2, distribution of the variables is normal. In this research, Kolmogorov-Smirnov test is used to determine the normality of data distribution. In regression test, there is no need to normality of all the data, but the factors (structures) should be normal (8). Therefore, the assumption of normality of the data at the significance level of 5% has been tested by Kolmogorov-Smirnov test. For this test, statistical hypotheses are considered as the following:
In the first hypothesis:
H0: TDCS affects the depression caused by methadone consumption.
H1: TDCS has no effect on depression caused by methadone consumption.
And in the second hypothesis:
H0: TDCS affects the anxiety caused by methadone consumption.
H1: TDCS has no effect on anxiety caused by methadone consumption.
The results of the data normality test are presented in table 2.
Table2. Data normality test
As presented in the above table, in all the cases, the significance value has been obtained more than 0.05. Therefore, there is no evidence for rejecting the null hypothesis which suggests the normality of the data. In other words, distribution of the research data is normal and parametric tests can be executed.
Information of Beck’s test
Table3. Score of Beck’s test
The data included in table 3 shows that among the 40-year sample group who responded Beck’s test, 25 people (62.5%) got a score of 1 to 10, 12 people (30%) got a score of 11 to 16, 2 people (5%) got a score of 21 to 30, and no one got the score of 40 or more.
Information of Berger’s inventory
Table4. Scores of Berger’s inventory
The data included in table 4 shows that among the 40-people sample group who responded Berger’s inventory, 5 people (12.5%) got a score of 20-31, 7 people (17.5%) got a score of 32-42, 22 people (55%) got a score of 43-53, 3 people (7.5%) got a score of 54-64, 2 people (5%) got a score of 65-75, and only one person (2.5%) got the score of 76 or more.
Testing the research hypotheses
Hypothesis1: TDCS affects the depression caused by methadone consumption.
For testing this hypothesis, t significance test was used. The data included in table 5 shows suggest that at the significance level of (sig=0.000), the variables of TDCS and depression have a relationship (r=0.615). It can be such analyzed that the correlation between the two variables is equal to 0.615 which is a good and strong correlation. The type of correlation between the two mentioned variables is direct (positive) and the significance level has been obtained as 0.000. Since the significance value (0.000) is less than the research alpha value (0.05), the relationship between the two variables is significant. So, the first research hypothesis is approved. As a result, it can be stated that there is a relationship between TDCS and depression caused by methadone consumption.
Table5. The relationship between TDCS and depression
Hypothesis2: TDCS affects the anxiety caused by methadone consumption.
The data included in table 6 shows suggest that at the significance level of (sig=0.05), the variables of TDCS and anxiety have a relationship (r=0.643). It can be such analyzed that the correlation between the two variables is equal to 0.643 which is a good and strong correlation. The type of correlation between the two mentioned variables is direct (positive) and the significance level has been obtained as 0.000. Since the significance value is less than the research alpha value (0.05), the relationship between the two variables is significant. So, this hypothesis is approved. As a result, it can be stated that TDCS affects the anxiety caused by methadone consumption.
Table6. Correlation test of the relationship between TDCS and anxiety
Table7. Variance analysis test for reviewing the respondents’ viewpoints
The data included in table 7 shows there is a meaningful relationship between TDCS and anxiety and depression.
Investigation of the research hypotheses by Wilcoxon test
After the approval of the used scale, the data collected by Wilcoxon test was used for investigating the research hypotheses.
The first hypothesis: TDCS affects the depression caused by methadone consumption.
In the first hypothesis, the relationship between TDCS and depression is investigated. The value of the correlation between the two variables of TDCS and depression observed in the SPSS software output is equal to 0.615 according to table 8. It suggests that correlation between these two variables has good and acceptable value. This test has been done at the significance level of 95%. So, error level is equal to 0.05, on in other words, error level is a=5%.
Table8. The effect of TDCS on depression
Also, by dividing the unstandardized beta coefficient by the standard error, the value of 9.352 is obtained which is larger than the critical value. Therefore, the observed beta coefficient is significant. The normal significance level is also less than the error level and it confirms the above mentioned finding. So, with a confidence level of 95%, it can be said that there is a relationship between TDCS and depression caused by methadone consumption.
The second hypothesis: TDCS affects the anxiety caused by methadone consumption.
In the second hypothesis, the relationship between TDCS and anxiety is investigated. The value of the correlation between the two variables of TDCS and anxiety observed in the SPSS software output is equal to 0.610 according to table 9. It suggests that correlation between these two variables has good and acceptable value. This test has been done at the significance level of 95%. So, error level is equal to 0.05, on in other words, error level is a=5%.
Table9. The effect of TDCS on anxiety
Also, by dividing the unstandardized beta coefficient by the standard error, the value of 9.359 is obtained which is larger than the critical value. Therefore, the observed beta coefficient is significant. The normal significance level is also less than the error level and it confirms the above mentioned finding. So, with a confidence level of 95%, it can be said that there is a relationship between TDCS and anxiety caused by methadone consumption.