Table 1.

Consent and participation

Age of CYP referred to CAMHS	CYP aged <11	CYP aged 11–15		CYP aged 16–17
Initial contact with	Parent/carer			Depends on contact details provided with the CAMHS referral*
Consent provided by	Parent/carer	Parent/carer	Parent/carer	CYP AND parent/carer (optional)	CYP
Assent provided by	None	CYP (optional)	None	None	None
Participant(s)	Parent/carer only	CYP and parent/carer dyad	Parent/carer only	CYP and parent/carer dyad	CYP only
Primary participant†	Parent/carer	Parent/carer	Parent/carer	CYP	CYP
Secondary participant	None	CYP	None	Parent/carer	None
DAWBA completed by	Parent/carer	Parent/carer AND CYP	Parent/carer	CYP AND parent/carer	CYP
Research questionnaires completed by	Parent/carer report on CYP Parent/carer self-report	Parent/carer report on CYP Parent/carer self-report CYP self-report	Parent/carer report on CYP Parent/carer self-report	CYP self-report Parent/carer report on CYP Parent/carer self-report	CYP self-report

For all CYP aged <16 the initial contact about the study will be with the parent/carer. The involvement of CYP aged 11–15 will be at the discretion of the parent/carer.

*For CYP aged 16–17 if the CYP’s contact details are provided on the CAMHS referral the first contact about the study will be with the CYP who can choose to nominate a parent/carer to participate in the trial alongside them or participate alone. If the parent/carer’s contact details only are available the first contact will be with the parent/carer and the parent/carer will be asked whether the CYP can also be contacted but may choose to refuse this. The parent/carer will not be able to participate in the STADIA trial without the involvement or consent of the CYP.

†The primary participant is the person who must provide consent as a minimum requirement in order for randomisation to take place. Assent (of CYP aged 11–15) and parental consent (for CYP aged 16 and 17) may also be sought but is not mandatory and therefore will not be required prior to randomisation.

CAMHS, Child and Adolescent Mental Health Services; CYP, children and young people; DAWBA, Development and Well-Being Assessment; STADIA, STAndardised DIagnostic Assessment for children and adolescents with emotional difficulties.