Further analysis showed that the interaction of time by group with the attention subscale, orientation subscale, and fluency subscale had significant effects. The language subscale only had a main effect on group but not on time or interaction. Short-term memory, long-term memory, visual construction, abstraction and judgment, or mental manipulation did not have any main effects on group, time, or interaction.
3.2.1. The differences in CASI scores among the three groups at visit 1 and visit 2
The results of the GEE analysis found a main effect of time (Wald χ2 = 5.22, df = 1, p = 0.02), especially for visit 2 (β = 5.77, p = 0.04). Group did not have a main effect (Wald χ2 = 2.13, df = 2, p = 0.34), and the interaction between group and time had no significance (Wald χ2 = 5.43, df = 2, p = 0.07).
3.2.2. The differences in the attention subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found a main effect of group (Wald χ2 = 13.52, df = 2, p = 0.001), especially for the BD group (β = 1.41, p = 0.00). However, time did not have a main effect (Wald χ2 = 0.16, df = 1, p = 0.69).
The interaction effect between time and group was significant (Wald χ2 = 8.99, df = 2, p = 0.01), especially for the BD group at visit 2 (β=-0.77, p = 0.02).
The scores on the attention subscale of the BD group at visit 2 were significantly lower than those of the BD group at visit 1 (mean difference=-0.68, p = 0.01) but also significantly higher than SZ group at visit 1 (mean difference = 0.73, p = 0.07).
The scores on the attention subscale for the BD group at visit 1 was significantly higher than the scores of the SZ group at visit 1 (mean difference = 1.41, p = 0.00) and at visit 1 (mean difference = 1.33, p = 0.00). Additionally, the attention subscale scores of the BD group at visit 1 were marginally higher than the scores of the SAD group at visit 1 (mean difference = 0.92, p = 0.05). The scores on the attention subscale for the SZ group at visit 2 were significantly lower than those of the SAD group at visit 2 (mean difference=-0.84, p = 0.04).
3.2.3. The differences on the orientation subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found a main effect of group (Wald χ2 = 7.764, df = 2, p = 0.02), especially for the BD group (β = 4.45, p = 0.00). The effect of time was not significant (Wald χ2 = 2.99, df = 1, p = 0.08).
The interaction effect between time and group was significant (Wald χ2 = 10.295, df = 2, p = 0.01), especially for the BD group at visit 2 (β=-3.36, p = 0.00).
The post-hoc test showed that the scores on the orientation subscale of the BD group at visit 2 were significantly lower than the scores of the BD group at visit 1 (mean difference=-2.92, p = 0.00). The scores on the orientation subscale of the BD group at visit 1 were significantly higher than the scores recorded for the SZ group at visit 1 (mean difference = 4.45, p = 0.00) and visit 2 (mean difference = 4.02, p = 0.00).
Additionally, the scores on the orientation subscale for the BD group at visit 1 were marginally higher than the scores for the SAD group at visit 1 (mean difference = 2.78, p = 0.056) and visit 2 (mean difference = 2.59, p = 0.054), respectively.
3.2.4. The differences on the fluency subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found a main effect of group (Wald χ2 = 6.86, df = 2, p = 0.03), especially for the BD group (β = 3.23, p = 0.000). Time also had a main effect (Wald χ2 = 11.90, df = 1, p = 0.00). The effect of interaction between time and group was significant (Wald χ2 = 47.01, df = 2, p = 0.00), especially for the BD group at visit 2 (β=-3.6, p = 0.00).
The post-hoc test showed that the scores on the fluency subscale for the BD group at visit 2 were significantly lower than at visit 1 (mean difference=-3.13, p = 0.00).
Additionally, the scores on the fluency subscale for the BD group at visit 1 were significantly higher than the scores for fluency for the SAD group at visit 1 (mean difference = 2.39, p = 0.00) and visit 2 (mean difference = 2.00, p = 0.02) and the scores on the fluency subscale for the SZ group at visit 1 (mean difference = 3.23, p = 0.000) and visit 2 (mean difference = 2.76, p = 0.000).
3.2.5. The differences on the language subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found a main effect of group (Wald χ2 = 43.31, df = 2, p = 0.00), especially on the BD group (β = 1.698, p = 0.000). Time (Wald χ2 = 0.37, df = 1, p = 0.54) and interaction between time and group (Wald χ2 = 0.69, df = 2, p = 0.71) did not have main effects.
3.2.6. The differences on the abstraction and judgment subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found no significant main effect for time (Wald χ2 = 0.68, df = 1, p = 0.41) or group (Wald χ2 = 1.19, df = 2, p = 0.55), and the interaction between group and time also had no significance (Wald χ2 = 0.25, df = 2, p = 088).
3.2.7. The differences on the visual construction subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found no significant main effect for time (Wald χ2 = 2.28, df = 1, p = 0.13) or group (Wald χ2 = 0.64, df = 2, p = 0.73), and the interaction between group and time also had no significance (Wald χ2 = 4.51, df = 2, p = 0.11).
3.2.8. The differences on the mental manipulation subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found no significant main effect for time (Wald χ2 = 0.02, df = 1, p = 0.89) or group (Wald χ2 = 1.89, df = 2, p = 0.39), and the interaction between group and time also had no significance (Wald χ2 = 1.31, df = 2, p = 0.52).
3.2.9. The differences on the long-term memory subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found no significant main effect for time (Wald χ2 = 0.69, df = 1, p = 0.41) or group (Wald χ2 = 2.53, df = 2, p = 0.28), and the interaction between group and time also had no significance (Wald χ2 = 4.9, df = 2, p = 0.09).
3.2.10. The differences on the short-term memory subscale among the three groups at visit 1 and visit 2
The results of the GEE analysis found no significant main effect for time (Wald χ2 = 0.32, df = 1, p = 0.57) or group (Wald χ2 = 2.50, df = 2, p = 0.29), and the interaction between group and time also had no significance (Wald χ2 = 0.81, df = 2, p = 0.67).