## Materials and Methods
### Instruments  
The following questionnaires were used:  
Stress Evaluation Questionnaire for COVID-19 (SEQ-COVID-19). An ad hoc instrument designed by the authors of the present study that included items on the stress situation in the face of COVID-19 as well as various sociodemographic variables aimed at the participating teachers (gender, age, years of experience, marital status, and whether they had offspring) (Appendix A). The items focused on COVID-19 collected information about the level of stress generated by: (1) being infected by COVID-19; (2) a family member being infected; (3) a co-worker being infected; (4) a student being infected; (5) the student's family being infected; and (6) friends being infected. A Likert-type scale ranging from 1 \"does not stress me at all\" to 10 \"stresses me a lot\" was used. The sum of the six items resulted in a variable called \"COVID-19 Stress\". This is used as a variable in the ANN.  
Maslach Burnout Inventory-General Survey. Spanish adaptation by [63] of the Maslach Burnout Inventory-General Survey (MBI-GS), based on the MBI by [8,9] and on the burnout construct defined by [64], according to which individuals who are subjected to continuous levels of stress at both personal and relational levels in the workplace may develop three dimensions: high burnout, high cynicism, and low professional efficacy. The MBI-GS is composed of 15 items divided as follows: items 1, 2, 3, 4, and 6 belong to the burnout dimension (example item: \"I am emotionally exhausted by my job\"), items 5, 7, 10, 11, 12, and 15 to the professional efficacy dimension (example item: \"I can effectively solve problems that arise in my job\") and, finally, items 8, 9, 13, and 14 to the cynicism dimension (example item: \"I have lost interest in my job since I started in this position\"). It should be added that each item in the questionnaire comes with a letter at the end of it, referring to the dimension to which it belongs. In addition, the items of which this questionnaire is composed must be answered through a Likert-type scale with the lowest score (0) being never/never and the highest score (6) always/every day. This questionnaire is reliable and valid. In the research carried out by [9], the 22-item instrument had a [PERSON]'s alpha of 0.9 for the emotional exhaustion dimension, 0.79 for the cynicism dimension, 0.71 for professional efficacy and, finally, an overall alpha of the three dimensions of 0.76. In global terms, the [PERSON]'s alpha obtained in this research was 0.8.  
Brief Resilience Coping Scale (BRCS). Instrument developed by [65] and adapted to Spanish by [66]. It consists of 4 items on a Likert-type scale from 1 to 5, where 1 means that it does not reflect a typical reaction at all and 5 reflects the usual way of responding. An example of a questionnaire item is \"I look for creative ways to cope with difficult situations\". Scores range from 4 to 20. According to the authors, a score of 13 points or less indicates low resilience. If the score obtained is equal to or higher than 17, it is said to be high resilience. It is a reliable and valid instrument. It has a [PERSON]'s alpha of 0.86. In the present investigation a Cronbach's alpha of 0.73 was obtained.