(c) Characteristics of between-group studies: measure of outcome

1st author (date)	ADHD symptoms	Cognitive/executive function	Emotional disturbance	Quality of life	Academic performance	Mindfulness
Bachmann (2018) [13]	CAARS-SR/OR	n-back	n.r.	n.r.	n.r.	n.r.
Bueno (2015) [44]	ASRS	ANT, CPT-2	BDI, STAI-T, PANAS-X	AAQoL	n.r.	n.r.
Cole (2016) [40]	ASRS v1.1, BIS-11	n.r.	BDI-II, BHS, STAXI	WHOQoL-BREF, QFS	n.r.	KIMS
Edel (2017) [32]	DSM-IV-(SR/OR)	n.r.	WRI	GSES	n.r.	MAAS
Fleming (2015) [35]	BAARS-IV, BADDS	CPT-2	BAI, BDI-II	AAQoL	GPA	FFMQ
Gu (2017) [48]	CAARS-S:SV	ANT	BAI; BDI-II	VAS	GPA	MAAS
Hepark (2019) [45]	CAARS-INV, CAARS-SR	BRIEF-ASR	BDI-II-NL, STAI	OQ 45.2	n.r.	KIMS
Janssen (2019) [50]	CAARS-INV:SV, CAARS-S: SV	BRIEF-A	n.r.	OQ 45.2, MHC-SF	n.r.	FFMQ-SF, SCF-SF
Mitchell (2017) [25]	Current ADHD Symptom Scale	DEFS, BRIEF-A, ANT, CPT, DST, TMT, WAIS-R	DERS, DTS	n.r.	n.r.	n.r.
Schoenberg (2014) [12]	CAARS-S:SV	CPT-X	n.r.	OQ 45.2	n.r.	KIMS

(2) ADHD symptoms: ASRS (v1.1) = Adult ADHD Self-Report Scale; BAARS-IV = Barkley Adult ADHD Rating Scale-IV; BADDS = Brown ADD Rating Scales; BIS-11 = 11th version of the Barratt Impulsiveness Scale; CAARS-S:SV = Conners' Adult ADHD Self-Rating Scale; CAARS-SV = Conners' Adult ADHD Rating Scales-Screening Version; CAARS-SR = self-report version of the Conners' Adult ADHD Rating Scale; CAARS-INV = investigator rating version of the Conners' Adult ADHD Rating Scale; DSM-IV-(SR/OR) = Diagnostic and Statistical Manual of Mental Disorders, 4th Edition (self-rating/other-rating). (2) Cognitive/executive function: ANT = Attention Network Task; BRIEF-A = Behavior Rating Inventory of Executive Functioning-Adult Version; BRIEF-ASR = Behavior Rating Inventory of Executive Function-Adult Self-Report version; CPT-2 = the Conners' Continuous Performance Test-2nd edition; CPT-X = visual Continuous Performance Task; DEFS = Deficits in Executive Functioning Scale; DST = Digit Span Test (WAIS-R); TMT = Trail Making Test; WAIS-R = Wechsler Adult Intelligence Scale-Revised. (3) Emotional disturbance: BAI = Beck Anxiety Inventory; BDI-II/BDI-II-NL = Beck Depression Inventory (2nd edition); BHS = Beck Hopelessness Scale; DERS = Difficulties in Emotion Regulation Scale; PANAS-X = Affect Schedule-Expanded form; STAI = State-Trait Anxiety Inventory; STAXI = State-Trait Anger Expression Inventory; WRI = Wender–Reimherr Interview. (4) Quality of life: AAQoL = Adult ADHD Quality of Life Questionnaire; GSES = Generalized Self-Efficacy Scale; MHC-SF = Positive Mental Health Short Form; OQ 45.2 = Outcome Questionnaire; QFS = questionnaire of social functioning; VAS = Visual Analog Scale (personal health status); WHOQoL-BREF = World Health Organization Quality of Life. (5) Mindfulness: MAAS = Mindful Attention Awareness Scale; FFMQ = Five Facet Mindfulness Questionnaire; KIMS = Kentucky Inventory of Mindfulness Skills; SCF-SF = Self-Compassion Short Form. (6) Academic performance: GPA = Grade Point Average.