### INTRODUCTION

### METHODS

### Study design and participants

### Measures

### Statistical analysis

*χ*

^{2}), root mean squared error of approximation (RMSEA), Tucker-Lewis index (TLI), and comparative fit index (CFI) based on the conventional guidelines set by Hu and Bentler [19]. TLI, CFI >0.95, RMSEA <0.06 values were considered evidence of a well-fitting model [19]. Cronbach’s alpha and McDonald’s omega were used to assess the internal consistency of the MIQ-T-SF. The scores for each subscale in the MIQ-T-SF were calculated as the sum of the subscale item scores. The normality of the distribution of the analyzed variables was assessed using the Shapiro-Wilk analysis. As the parameters did not follow a normal distribution, non-parametric analyses were performed in correlation tests among the subscales and for concurrent validity with the TEMPS-A and PAI-BOR (Spearman’s correlation test), as well as in tests used to compare scores between gender and age groups (Kruskal-Wallis analysis). Multi-group CFA was used to evaluate measurement invariance in order to confirm that MIQ-T-SF was assessing the same construct across gender and age groups. We examined the evidence for configural invariance (equality of factor structures), metric invariance (equality of factor loadings), and scalar invariance (equality of item intercepts). For configural invariance, the goodness-of-fit was evaluated using similar guidelines as the CFA: CFI >0.95, RMSEA <0.06. For metric and scalar invariance, the variance of CFI and RMSEA (ΔCFI, ΔRMSEA) were used as indices. ΔCFI <0.01 and ΔRMSEA <0.015 were considered acceptable values as evidence of invariance [20,21]. R 3.5.1 (R Foundation for Statistical Computing, Vienna, Austria; https://cran.r-project.org/bin/windows/base/old/3.5.1/) software was used for all statistical analyses.

### RESULTS

### Clinical and demographic characteristics

### EFA

### CFA

*χ*

^{2}=74.81; degrees of freedom=109; p>0.05; RMSEA=0.038; RMSEA 95% confidence interval=0.030–0.047; TLI=0.952; CFI=0.961). As the

*χ*

^{2}is heavily influenced by sample size [22], it is reported here only for completeness of data.

### Reliability analysis and correlations within the MIQ-T-SF scales

_{t}=0.90), Downward Tendency (α=0.86, Ω

_{t}=0.86), Upward Tendency (α=0.71, Ω

_{t}=0.72), Seasonality (α=0.83, Ω

_{t}=0.84), and Childhood Instability (α=0.85, Ω

_{t}=0.85), all had a reliability coefficient of 0.7 or higher. The complete MIQ-T-SF showed a Cronbach’s alpha value of 0.90 and McDonald’s omega value of 0.92, indicating excellent internal consistency.