Table 2 Questionnaires employed at the different study assessment times

 Gender

1

X

 Month& year of birth

2

X

 Family status & partner

3

X

 Education

2

X

 Employment

2

X

 Income

1

X

 Subjective general health (SF-1)

1

X

X

X

 Quality of life (EUROHIS-QoL Index)

8

X

X

X

 Self-construal Scale (SCS)

24

X

 Subjective Socio-Economic Status

1

X

 Continuum beliefs (CB_new)

12

X

X

X

X

 Causal beliefs (List)

18

X

X

X

X

 Mental health literacy, depression specific (D-Lit)

12

X

X

X

X

 Self-efficacy to help oneself

6

X

X

X

X

 Self-efficacy to seek out professional help

7

X

X

X

X

 Subjective sense of illness (B-IPQ-R)

9

X

X

X

 Self-identification as mentally ill (SELF-I)

5

X

X

X

X

 Attitudes towards help-seeking (ATSPPH-SF)

10

X

X

X

X

 Motivation behind help-seeking (ACMQ)

6

X

X

 Help-seeking intention (List)

16

X

X

X

X

 Help-seeking subjective norms, attitudes and perceived control (TPB)

10

X

X

X

X

 Help-seeking behaviour/ health-care utilisation

18

X

X

 Perceived public stigma and the agreement with stigma (SSMIS-public & -self-SF)

10

X

X

X

X

 Social distance stigma (SDS)

7

X

X

X

X

 Discrimination of mental illness

3

X

X

X

X

 Sense of blame for mental illness

4

X

X

X

X

 Self-stigma for seeking out professional help (SSOSH-SF)

3

X

X

X

X

 Shame for being mentally ill and seeking out help

2

X

X

X

X

 Emotional reaction towards a person with mental illness (ERMIS)

10

X

X

X

X

 Depressive Symptoms (PHQ-9)

9

X

X

X

X

 Anxiety Symptoms (PHQ-anxiety module)

7

X

 Differential diagnosis

1

X

 Previous treatment experience

3–7

X

 Perceived availability and accessibility to the health care system

1–5

X

 Covid-19 questions

4

X

X

X

∑ = 246