**2. STUDY 1: the DGEEC study**

#### **2.1 Methods**

### *2.1.1 Procedures*

The *Psychological Health and Well-Being | School study* (also called the DGEEC study) was done by the Directorate General of Education and Science Statistics, the Directorate General of Education, the National Programme for the Promotion of School Success, Aventura Social Team/ISAMB, the University of Lisbon, the Order of Portuguese Psychologists, and the Calouste Gulbenkian Foundation, with the approval of the Ministry of Education.

Schools and classes were chosen randomly from a national list, and all the ethical procedures, authorisations, and anonymous and voluntary participation were guaranteed. Questionnaires were administered online. Full details are in the final national report of the DGEEC study [4].

### *2.1.2 Participants*

This study included 4444 pupils (*M* = 13.39 ± 2.414; Min = 9 e Max = 18), of whom 52.2% are girls. 27.2% of the participants attended the 2nd cycle of schooling, and 72.8% attended lower and upper secondary education.

### **2.2 Instruments**

The measures and variables under study are described in **Table 1**.

### **2.3 Statistical analysis and main results**

Two groups were created from the measurement of life satisfaction (low—50.3%; high—49.7%) and two groups were created from the evaluation of psychological symptoms (reduced—53.4%; and pronounced—46.6%). In both variables, the median was used as a cut-off point). The combination of four situations resulted in four groups: (1) *Complete Psychological Health*—high life satisfaction and low psychological symptoms (35.6%); (2) *Incomplete Psychological Health*—low life satisfaction and low psychological symptoms (17.7%); (3) *Incomplete Psychological Distress*—high life satisfaction and pronounced psychological symptoms (14.1%); (4) *Complete Psychological Distress*—low life satisfaction and pronounced psychological symptoms (32.6%).

Age and gender differences and differences related to lifestyles and perceptions of quality of life were analysed through Chi-squares or ANOVAS. A significant level was set at *p* < .05.
