TABLE 1.

Summary of primary measures in TIGER.

Method	Measure	Domain assessed	V1	V2	M
Clinical interview:	K-SADS-PL	Clinical diagnosis	X
	CDRS-R	Depression symptom severity	X
	C-SSR-S	Suicidal ideation and behaviors	X
	SITBI	Non-suicidal self-injury	X
	FIGS*	Family psychiatric history	X
Self-report:	Tanner	Pubertal development	X
	RADS-2	Depression symptom severity	X		X
	SIQ-JH	Explicit suicidal ideation	X
	PHQ-9	Depression symptom severity	X		X
	MASC-2	Anxiety symptom severity	X		X
	MPVS	Bullying	X
	STRAIN	Life stress	X
	CTQ*	Childhood trauma	X
	DERS*	Emotion regulation difficulties	X
MRI:	T1-weighted SPGR	Grey and white matter		X
	Resting-state fMRI	Functional connectivity		X
	Diffusion-weighted MRI	Structural connectivity		X
	1H-MRS (ACC)	Glutamate, Glutathione, Ascorbate		X
	ACC Glu	Glutamate		X
	ACC GSH and ACC Asc	Antioxidants		X
Cognitive task:	IAT – death version	Implicit suicidal ideation		X
Blood:	IL-1β, IL-6, IL-10, TNF-α	Inflammation		X

Measures will be assessed at all three timepoints unless marked with a * which indicates the measure will only be administered at T1. Measures under column “M” are administered at the bi-monthly online follow-up assessments.