Table 1 Overview of the questionnaires being used

PSS-10: Perceived Stress Scale

(primary outcome measure)

Primary objective

Developed by Cohen, Kamarck, and Mermelstein, translated and validated by Klein, Brähler et al., 2016 [47]. Investigates the degree to which life was unpredictable, uncontrollable, and overwhelming within the last month. Very good internal consistency (a = .84). Positive correlation with depression and anxiety, negative one with quality of life.

10 items

DERS-SF: Difficulties in Emotion Regulation Scale Short Form

Measures emotion (dys-)regulation multidimensional. According to the model by Gratz and Roemer [48], the subscales “non-acceptance”, “problems with target oriented behaviour”, “impulsive conduct problems”, “lack of emotional awareness”, “limited access to emotion regulation strategies”, and “lack of emotional clarity”.

16 items

SCS: Self-Compassion Scale

The Self-Compassion Scale was developed by Neff in 2003 with 26 items. The shortened version showed satisfactory to good psychometric properties so far [49].

12 items

WHO-5: WHO Fragebogen zum Wohlbefinden

The facets of psychological well-being like mood, interest, energy, and drive within the last 2 weeks are assessed. Used worldwide, non-invasive questions, translated in 30 languages, the first version was published in 1998. Very good internal consistency with α = .85. German version by Allgaier [50].

5 items

PHQ-4: Gesundheitsfragebogen für Patienten – Depressionsmodul

The PHQ-4 is a valid screening instrument for symptoms of depression and anxiety symptoms (Cronbach α >0.80) [51]. Responses are scored as 0 (“not at all”), 1 (“several days”), 2 (“more than half the days”), or 3 (“nearly every day”). PHQ–4 scores go from normal (0 –2) to mild (3–5) to moderate (6–8) to severe (9 –12). Symptoms within the last 2 weeks are being interrogated.

4 items

DSHI-9: Deliberate Self-Harm Inventory

An initial question is asked whether someone has already intentionally injured his-/herself. If this is answered with yes, the type, onset, and frequency of self-harm are obtained [52].

1–6 items

ISI: Insomnia Severity Index

Measures the quality of sleep and goes back to [53]. Difficulties falling asleep or staying asleep and the impairment they cause in everyday life are in the focus.

7 items

SEED: Short Evaluation of Eating Disorders

It obtains the central symptoms of anorexia (underweight, fear of weight gain, impaired body awareness) and bulimia (binge eating, compensatory measures, excessive preoccupation with figure and weight) within the last month [54]. It has already been used in student samples with good experience.

6 items

SFF: Schutzfaktoren

This short questionnaire captures three scales of protective factors that correlate significantly with data from the SDQ. Children who have more social, personal, and family resources are correspondingly less conspicuous in the SDQ [55].

12 items

SISE: Single-Item Self-Esteem Scale

This 1-item version goes back to the 10-item scale of the Rosenberg Self-Esteem Scale (RSES) developed by Rosenberg in 1965. The original sheet captured self-esteem with 5 positive and 5 negative questions. Recent studies have also demonstrated very good measurement properties for the 1-item version [56]. The question asks how well the statement “I have high self-esteem” applies to oneself. A 4-point Likert scale is then presented.

1 item

CD-RISC-10: Connor-Davidson Resilience Scale-short form

The long version was designed by Connor-Davidson in 2003 to measure resilience. Resilience means the ability to cope with internal or external stressors. The CD-RISC is widely used and has good psychometric properties (a = .84) [57]

10 items

FAS III: Family Affluence Scale

The FAS III measures the socioeconomic status using 6 questions and has very good quality criteria. Furthermore, the MacArthur scale question is connected, which asks about the subjective assessment of the prosperity of the adolescents’ own family [58]

6 items

+ 1