Table 1 Inclusion and exclusion criteria

Inclusion criteria

• Age ≥18 years

• Biological parent/carer/non-biological parent/grandparent/legal guardian

• Access to the internet and personal email account

• Mobile phone number

• Aged 11–15 years

• Parent/carer has given informed consent

• Has a reading age of 11+ years

• Access to mobile phone and internet

• Living with participating parent/carer

• Score 7 or above on Short Mood and Feelings Questionnaire (SMFQ)

Exclusion criteria