Table 1.

Description of included studies.

Author	Year	Cases	sample	region	education	types of substance	Study design	Quality score
Gobeje et al. [28]	2019	171	502	Amhara	High School	ALL substances	Cross-sectional	8
Eyasu t al [34]	2018	270	1211	SNNPR	College	Khat	Cross-sectional	7
Gebremariam et al. [7]	2018	69	695	Amhara	University	ALL substances	Cross-sectional	5
Mesfin et al. [33]	2017	138	384	SNNPR	College	ALL substances	Cross-sectional	8
kassa et al. [29]	2017	51	1577	SNNPR	High School	Khat	Cross-sectional	8
Gamachu et al. [54]	2017	417	648	Somalia	University	ALL substances	Cross-sectional	7
Abdeta et al. [11]	2017	30	296	Oromia	University	Khat	Cross-sectional	4
Adere et al. [24]	2017	238	730	Amhara	University	ALL substances	Cross-sectional	6
Dires et al. [55]	2016	47	296	Oromia	High School	Khat	Cross-sectional	8
Haftay et al. [1]	2016	57	471	Tigray	University	ALL substances	Cross-sectional	7
Berihun et al. [56]	2015	213	118	Addis	High School	ALL substances	Cross-sectional	7
Teshome et al. [19]	2015	343	728	Oromia	University	Khat	Cross-sectional	8
Astatkie et al. [23]	2015	784	1290	SNNPR	University	Khat	Cross-sectional	7
Wazema and Madhavi [57]	2015	76	620	Oromia	University	Khat	Cross-sectional	7
Awoke et al. [43]	2014	347	378	Amhara	High School	Khat	Cross-sectional	7
Ahmed et al. [30]	2014	174	220	Oromia	High School	ALL substances	Cross-sectional	8
berhanu et al. [44]	2014	190	651	Amhara	High School	ALL substances	Cross-sectional	7
Gebrehanna et al. [9]	2014	230	3268	Amhara	University	Khat	Cross-sectional	6
Tsegay et al. [13]	2014	314	845	Amhara	University	ALL substances	Cross-sectional	8
Moges [22]	2014	150	623	SNNPR	University	ALL substances	Cross-sectional	7
Tesfaye et al. [20]	2014	70	1040	Harari	University	ALL substances	Cross-sectional	4
Kassa et al. [21]	2014	262	586	SNNPR	University	ALL substances	Cross-sectional	4
Eticha and Kidane [14]	2014	457	193	Tigray	University	Cigarrate	Cross-sectional	8
Yeshalem et al. [31]	2013	60	754	Amhara	College	Khat	Cross-sectional	7
Tesfahun et al. [58]	2013	644	423	Amhara	College	ALL substances	Cross-sectional	7
Gebreslassie et al. [10]	2013	203	764	Tigray	University	ALL substances	Cross-sectional	4
Rada et al. [44]	2012	406	1890	Harari	High School	Khat	Cross-sectional	8
Deressa et al. [16]	2011	142	622	Addis	University	ALL substances	Cross-sectional	6
Legese et al. [59]	2004	146	127	Oromia	University	Khat	Cross-sectional	7