##        id   D.prime C.score Anxiety Depression Stress ADHD
## 1  SADP01 1.5109000 0.83405      14         18     18   35
## 2  SADP05 1.0802500 0.69785      25         23     26   56
## 3  SADP09 0.9512000 0.58595      28         31     41   60
## 4  SADP11 1.9284500 0.99565      16         22     27   62
## 5  SADP13 1.3711500 0.77985      38         40     47   63
## 6  SADP14 2.8855000 1.47420      28         20     26   49
## 7  SADP15 1.2820000 0.76685      15         14     14   48
## 8  SADP18 1.1553500 0.73520      14         14     20   54
## 9  SADP25 1.0196500 0.63560      18         42     27   36
## 10 SADP27 0.4636500 0.55330      44         48     42   53
## 11 SADP29 1.3057500 0.81030      28         25     31   57
## 12 SADP30 1.1747000 0.85790      16         19     15   36
## 13 SADP36 1.5314500 0.84430      19         15     21   40
## 14 SADP37 1.9480500 1.03690      18         18     22   31
## 15 SADP40 1.5944000 0.86010      14         14     14   36
## 16 SADP42 0.9199500 0.63345      25         34     29   38
## 17 SADP43 2.6623000 1.39405      16         14     16   36
## 18 SADP44 0.5044000 0.49025      46         23     51   73
## 19 SADP45 0.1105636 0.76565      34         33     45   68
## 20 SADP46 1.1947500 0.77085      15         11     18   53
## 21 SADP47 1.5266500 0.82620       7          9     11   67
## 22 SADP56 1.2330000 1.35450      15         10     12   45

Correlation

Correlation Plot (Heat Map) showing the significance pair at alpha = 0.05

Those in Blue color is significant at alpha = 0.05.
Those in Blank/White color is NOT significant at alpha = 0.05.

In this plot, blue = positive relationship, red = negative relationship, the darker shade indicated a stronger relationship.

ADHD is NOT correlated with BOTH D Prime and C score. Therefore I disregard ADHD in all of these mediation model.

Depression - Stress - D Prime – NOT SIGNIFICANT

## 
## Call:
## lm(formula = D.prime ~ Depression, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.9398 -0.2793 -0.1285  0.1739  1.4806 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  1.95036    0.28779   6.777 1.37e-06 ***
## Depression  -0.02727    0.01151  -2.370    0.028 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5792 on 20 degrees of freedom
## Multiple R-squared:  0.2193, Adjusted R-squared:  0.1802 
## F-statistic: 5.617 on 1 and 20 DF,  p-value: 0.02796
## 
## Call:
## lm(formula = Stress ~ Depression, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -15.2910  -4.6918  -0.2953   2.0064  24.6121 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   7.1367     4.0125   1.779   0.0905 .  
## Depression    0.8370     0.1604   5.217 4.18e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 8.075 on 20 degrees of freedom
## Multiple R-squared:  0.5764, Adjusted R-squared:  0.5553 
## F-statistic: 27.22 on 1 and 20 DF,  p-value: 4.182e-05
## dv ~ iv + m
## 
## Call:
## lm(formula = D.prime ~ Depression + Stress, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.74877 -0.37274 -0.14840  0.07263  1.52018 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.08350    0.30682   6.791 1.75e-06 ***
## Depression  -0.01166    0.01752  -0.665    0.514    
## Stress      -0.01866    0.01589  -1.174    0.255    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5738 on 19 degrees of freedom
## Multiple R-squared:  0.2721, Adjusted R-squared:  0.1955 
## F-statistic: 3.551 on 2 and 19 DF,  p-value: 0.04895
## 
## Causal Mediation Analysis 
## 
## Nonparametric Bootstrap Confidence Intervals with the Percentile Method
## 
##                Estimate 95% CI Lower 95% CI Upper p-value   
## ACME            -0.0156      -0.0444         0.03  0.3090   
## ADE             -0.0117      -0.0529         0.02  0.2432   
## Total Effect    -0.0273      -0.0474        -0.01  0.0034 **
## Prop. Mediated   0.5726      -1.4057         1.86  0.3076   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Sample Size Used: 22 
## 
## 
## Simulations: 10000

Depression - Anxiety - D Prime – NOT SIGNIFICANT

## 
## Call:
## lm(formula = D.prime ~ Depression, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.9398 -0.2793 -0.1285  0.1739  1.4806 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  1.95036    0.28779   6.777 1.37e-06 ***
## Depression  -0.02727    0.01151  -2.370    0.028 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5792 on 20 degrees of freedom
## Multiple R-squared:  0.2193, Adjusted R-squared:  0.1802 
## F-statistic: 5.617 on 1 and 20 DF,  p-value: 0.02796
## 
## Call:
## lm(formula = Anxiety ~ Depression, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -17.4696  -3.6516  -0.3479   3.4861  23.3156 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   7.2076     3.7650   1.914 0.069993 .  
## Depression    0.6729     0.1505   4.470 0.000235 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 7.577 on 20 degrees of freedom
## Multiple R-squared:  0.4998, Adjusted R-squared:  0.4747 
## F-statistic: 19.98 on 1 and 20 DF,  p-value: 0.0002347
## dv ~ iv + m
## 
## Call:
## lm(formula = D.prime ~ Depression + Anxiety, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8715 -0.3154 -0.1328  0.0761  1.5898 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.05772    0.31502   6.532 2.96e-06 ***
## Depression  -0.01725    0.01637  -1.054    0.305    
## Anxiety     -0.01490    0.01720  -0.866    0.397    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5828 on 19 degrees of freedom
## Multiple R-squared:  0.2489, Adjusted R-squared:  0.1699 
## F-statistic: 3.148 on 2 and 19 DF,  p-value: 0.06592
## 
## Causal Mediation Analysis 
## 
## Nonparametric Bootstrap Confidence Intervals with the Percentile Method
## 
##                Estimate 95% CI Lower 95% CI Upper p-value   
## ACME            -0.0100      -0.0344         0.05  0.4934   
## ADE             -0.0172      -0.0773         0.01  0.1678   
## Total Effect    -0.0273      -0.0469        -0.01  0.0038 **
## Prop. Mediated   0.3676      -1.9917         1.58  0.4936   
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Sample Size Used: 22 
## 
## 
## Simulations: 10000

Anxiety - Depression - D Prime – NOT SIGNIFICANT

## 
## Call:
## lm(formula = D.prime ~ Anxiety, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.9026 -0.3295 -0.2052  0.1205  1.7061 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  1.95513    0.30041   6.508 2.41e-06 ***
## Anxiety     -0.02771    0.01220  -2.271   0.0343 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5844 on 20 degrees of freedom
## Multiple R-squared:  0.205,  Adjusted R-squared:  0.1653 
## F-statistic: 5.159 on 1 and 20 DF,  p-value: 0.03433
## 
## Call:
## lm(formula = Depression ~ Anxiety, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -17.111  -3.645  -1.629   3.577  22.684 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   5.9482     4.0918   1.454 0.161549    
## Anxiety       0.7427     0.1662   4.470 0.000235 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 7.96 on 20 degrees of freedom
## Multiple R-squared:  0.4998, Adjusted R-squared:  0.4747 
## F-statistic: 19.98 on 1 and 20 DF,  p-value: 0.0002347
## dv ~ iv + m
## 
## Call:
## lm(formula = D.prime ~ Anxiety + Depression, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.8715 -0.3154 -0.1328  0.0761  1.5898 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.05772    0.31502   6.532 2.96e-06 ***
## Anxiety     -0.01490    0.01720  -0.866    0.397    
## Depression  -0.01725    0.01637  -1.054    0.305    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5828 on 19 degrees of freedom
## Multiple R-squared:  0.2489, Adjusted R-squared:  0.1699 
## F-statistic: 3.148 on 2 and 19 DF,  p-value: 0.06592
## 
## Causal Mediation Analysis 
## 
## Nonparametric Bootstrap Confidence Intervals with the Percentile Method
## 
##                Estimate 95% CI Lower 95% CI Upper p-value  
## ACME            -0.0128      -0.0785         0.01   0.179  
## ADE             -0.0149      -0.0422         0.06   0.479  
## Total Effect    -0.0277      -0.0478         0.00   0.044 *
## Prop. Mediated   0.4623      -1.0072         5.83   0.222  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Sample Size Used: 22 
## 
## 
## Simulations: 10000

Anxiety - Stress - D Prime – NOT SIGNIFICANT

## 
## Call:
## lm(formula = D.prime ~ Anxiety, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -0.9026 -0.3295 -0.2052  0.1205  1.7061 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  1.95513    0.30041   6.508 2.41e-06 ***
## Anxiety     -0.02771    0.01220  -2.271   0.0343 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5844 on 20 degrees of freedom
## Multiple R-squared:  0.205,  Adjusted R-squared:  0.1653 
## F-statistic: 5.159 on 1 and 20 DF,  p-value: 0.03433
## 
## Call:
## lm(formula = Stress ~ Anxiety, data = dc[, -1])
## 
## Residuals:
##    Min     1Q Median     3Q    Max 
## -7.210 -3.133 -0.226  2.604  8.956 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.00329    2.40254   0.834    0.414    
## Anxiety      1.07288    0.09756  10.998 6.25e-10 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 4.674 on 20 degrees of freedom
## Multiple R-squared:  0.8581, Adjusted R-squared:  0.851 
## F-statistic: 120.9 on 1 and 20 DF,  p-value: 6.249e-10
## dv ~ iv + m
## 
## Call:
## lm(formula = D.prime ~ Anxiety + Stress, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.69475 -0.34515 -0.18738  0.08444  1.51344 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.018999   0.303163   6.660 2.28e-06 ***
## Anxiety      0.006499   0.032126   0.202    0.842    
## Stress      -0.031881   0.027738  -1.149    0.265    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5798 on 19 degrees of freedom
## Multiple R-squared:  0.2567, Adjusted R-squared:  0.1785 
## F-statistic: 3.281 on 2 and 19 DF,  p-value: 0.05969
## 
## Causal Mediation Analysis 
## 
## Nonparametric Bootstrap Confidence Intervals with the Percentile Method
## 
##                Estimate 95% CI Lower 95% CI Upper p-value  
## ACME            -0.0342      -0.1204         0.03   0.300  
## ADE              0.0065      -0.0547         0.10   0.885  
## Total Effect    -0.0277      -0.0467         0.00   0.044 *
## Prop. Mediated   1.2346      -1.8570         8.74   0.343  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Sample Size Used: 22 
## 
## 
## Simulations: 10000

Stress - Depression - D Prime – NOT SIGNIFICANT

## 
## Call:
## lm(formula = D.prime ~ Stress, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.71794 -0.35071 -0.18655  0.09339  1.55001 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.02925    0.29164   6.958 9.38e-07 ***
## Stress      -0.02668    0.01020  -2.617   0.0165 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5657 on 20 degrees of freedom
## Multiple R-squared:  0.2551, Adjusted R-squared:  0.2179 
## F-statistic:  6.85 on 1 and 20 DF,  p-value: 0.0165
## 
## Call:
## lm(formula = Depression ~ Stress, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -16.7766  -2.8497  -1.4606   0.8225  18.7517 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)   4.6540     3.7762   1.232    0.232    
## Stress        0.6887     0.1320   5.217 4.18e-05 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 7.325 on 20 degrees of freedom
## Multiple R-squared:  0.5764, Adjusted R-squared:  0.5553 
## F-statistic: 27.22 on 1 and 20 DF,  p-value: 4.182e-05
## dv ~ iv + m
## 
## Call:
## lm(formula = D.prime ~ Stress + Depression, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.74877 -0.37274 -0.14840  0.07263  1.52018 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.08350    0.30682   6.791 1.75e-06 ***
## Stress      -0.01866    0.01589  -1.174    0.255    
## Depression  -0.01166    0.01752  -0.665    0.514    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5738 on 19 degrees of freedom
## Multiple R-squared:  0.2721, Adjusted R-squared:  0.1955 
## F-statistic: 3.551 on 2 and 19 DF,  p-value: 0.04895
## 
## Causal Mediation Analysis 
## 
## Nonparametric Bootstrap Confidence Intervals with the Percentile Method
## 
##                Estimate 95% CI Lower 95% CI Upper p-value  
## ACME           -0.00803     -0.04949         0.01   0.244  
## ADE            -0.01866     -0.03878         0.03   0.309  
## Total Effect   -0.02668     -0.04436        -0.01   0.012 *
## Prop. Mediated  0.30084     -0.64925         3.75   0.256  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Sample Size Used: 22 
## 
## 
## Simulations: 10000

Stress - Anxiety - D Prime – NOT SIGNIFICANT

## 
## Call:
## lm(formula = D.prime ~ Stress, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.71794 -0.35071 -0.18655  0.09339  1.55001 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.02925    0.29164   6.958 9.38e-07 ***
## Stress      -0.02668    0.01020  -2.617   0.0165 *  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5657 on 20 degrees of freedom
## Multiple R-squared:  0.2551, Adjusted R-squared:  0.2179 
## F-statistic:  6.85 on 1 and 20 DF,  p-value: 0.0165
## 
## Call:
## lm(formula = Anxiety ~ Stress, data = dc[, -1])
## 
## Residuals:
##     Min      1Q  Median      3Q     Max 
## -7.1725 -3.0252  0.4271  2.3752  8.8302 
## 
## Coefficients:
##             Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  1.57757    2.08044   0.758    0.457    
## Stress       0.79981    0.07273  10.998 6.25e-10 ***
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 4.035 on 20 degrees of freedom
## Multiple R-squared:  0.8581, Adjusted R-squared:  0.851 
## F-statistic: 120.9 on 1 and 20 DF,  p-value: 6.249e-10
## dv ~ iv + m
## 
## Call:
## lm(formula = D.prime ~ Stress + Anxiety, data = dc[, -1])
## 
## Residuals:
##      Min       1Q   Median       3Q      Max 
## -0.69475 -0.34515 -0.18738  0.08444  1.51344 
## 
## Coefficients:
##              Estimate Std. Error t value Pr(>|t|)    
## (Intercept)  2.018999   0.303163   6.660 2.28e-06 ***
## Stress      -0.031881   0.027738  -1.149    0.265    
## Anxiety      0.006499   0.032126   0.202    0.842    
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Residual standard error: 0.5798 on 19 degrees of freedom
## Multiple R-squared:  0.2567, Adjusted R-squared:  0.1785 
## F-statistic: 3.281 on 2 and 19 DF,  p-value: 0.05969
## 
## Causal Mediation Analysis 
## 
## Nonparametric Bootstrap Confidence Intervals with the Percentile Method
## 
##                Estimate 95% CI Lower 95% CI Upper p-value  
## ACME             0.0052      -0.0444         0.08   0.887  
## ADE             -0.0319      -0.1087         0.02   0.308  
## Total Effect    -0.0267      -0.0443        -0.01   0.013 *
## Prop. Mediated  -0.1948      -4.1352         2.54   0.897  
## ---
## Signif. codes:  0 '***' 0.001 '**' 0.01 '*' 0.05 '.' 0.1 ' ' 1
## 
## Sample Size Used: 22 
## 
## 
## Simulations: 10000