The connecting adolescents to reduce relapse (CARR) trial: study protocol for a randomized controlled trial comparing the efficacy of Groups 4 Health and cognitive behaviour therapy in young people

Table 1 Overview of CARR measures and timepoints of measurement

Construct	Measure	T0 Baseline	T1 After session 1	T2 After session 2	T3 After session 3	T4 After session 4	T5 Post-treatment	T6 6-month follow up	T7 12-month follow up
Primary outcomes	Depression (DASS-21)	•	•	•	•	•	•	•	•
	Depression (PHQ-9)	•					•	•	•
	Loneliness (4 item)	•	•	•	•	•	•	•	•
	Loneliness (20 item)	•					•	•	•
Secondary outcomes	Social anxiety	•					•	•	•
	GP attendance (last month)	•					•	•	•
	Wellbeing	•					•	•	•
	Life satisfaction	•					•	•	•
	Self esteem	•					•	•	•
	Subjective physical health	•					•	•	•
Process measures	Multiple group membership	•					•	•	•
	Multiple group compatibility	•					•	•	•
	Mental illness identity	•					•	•	•
	Group cohesion						•
	Therapy group identification		•	•	•	•	•
	Service identification						•
Acceptability/feasibility	Useful		•	•	•	•	•	•	•
	Enjoyed						•	•	•
	Interesting						•	•	•
	Learnt something						•	•	•
	Homework completion		•	•	•	•	•
	Facilitator questionnaire		•	•	•	•	•
	Attendance		•	•	•	•	•