Characteristics of included studies
| Author (year) | Region | Design | Isotretinoin users | Mean/median age (year) | Female (%) | Acne severity | Comparison groups | Dose | Treatment duration | Depression assessment |
| Kellett et al (1999)23 | UK | Prospective | 34 | 24 | 44 | NA | Before versus after | 1.0 mg/(kg⋅d) | 4 months | HADS-D |
| Jick et al 24 (2000) a | Canada | Retrospective | 7195 | <30 (75%) | 47 | NA | Before versus after | 40 mg (86%) | 3–6 months (62%) | ICD code |
| Jick et al 24 (2000) b | UK | Retrospective | 340 | <30 (78%) | 42 | NA | Before versus after | 20 mg (75%) | 1–2 months (81%) | ICD code |
| Ng et al 25 (2002) | Australia | Prospective | 174 | 20 | 41 | Moderate to severe | Before versus after | 0.8–1.0 mg/(kg⋅d) | 6 months | BDI |
| Ferahbas et al 26 (2004) | Turkey | Prospective | 23 | 20 | 43 | Severe | Before versus after | 0.5–1.0 mg/(kg⋅d) | 4 months | MADRS |
| Kellett et al 28 (2005) | UK | Prospective | 33 | 25 | 36 | NA | Before versus after | 1.0 mg/(kg⋅d) | 4 months | BDI |
| Kaymak et al 29 (2006) | Turkey | Prospective | 24 | 100 | 58 | Moderate | Before versus after | 0.75–1.0 mg/(kg⋅d) | 5–7 months | HRS |
| Chia et al 27 (2005) | USA | Prospective | 59 | 12–19 | 25 | Moderate to severe | Before versus after | 1.0 mg/(kg⋅d) | 3–4 months | CES-D |
| Azoulay et al 31 (2008) | Canada | Retrospective | 126 | 28 | 53 | NA | Users versus non-users | NA | 5 months | ICD code |
| Kaymak et al 33 (2009) | Turkey | Prospective | 37 | 21 | 69 | Mild to severe | Before versus after | 0.5–0.8 mg/(kg⋅d) | >5 months | BDI, HADS-D |
| Bozdag et al 32 (2009) | Turkey | Prospective | 50 | 20 | 52 | Moderate to severe | Before versus after | 1.0 mg/(kg⋅d) | 4 months | BDI |
| Rehn et al 34 (2009) | Finland | Prospective | 126 | 20 | 0 | Moderate to severe | Before versus after | 0.5 mg/(kg⋅d) | 3 months | BDI |
| Simic et al 35 (2009) | Bosnia and Herzegovina | Prospective | 85 | 19 | 34 | Moderate to severe | Isotretinoin versus vitamin C | 1.0 mg/(kg⋅d) | 2 months | BDI |
| McGrath et al 36 (2010) | UK | Prospective | 65 | 20 | 31 | Mean AGS score 3.3 | Before versus after | 0.5–1.0 mg/(kg⋅d) | 3 months | CES-D |
| Ergun et al 38 (2012) | Turkey | Prospective | 65 | 22 | 73 | Severe or resistant | Before versus after | 0.5–1.0 mg/(kg⋅d) | ≈ 5 months | HADS-D |
| Ormerod et al 39 (2012) | UK | Prospective | 16 | 22 | 25 | Severe | Before versus after | 0.5–1.0 mg/(kg⋅d) | 3–6 months | BDI |
| Yesilova et al 40 (2012) | Turkey | Prospective | 43 | 23 | 70 | Mild to severe | Before versus after | 0.5–1.0 mg/(kg⋅d) | 6 months | HADS-D |
| Marron et al 41 (2013) | Spain | Prospective | 346 | 21 | 59 | Moderate | Before versus after | Total: 120 mg/kg | 7 months | HADS-D |
| Fakour et al 37 (2014) | Iran | Prospective | 98 | 22 | 61 | Severe | Before versus after | 0.5 mg/(kg⋅d) | 4 months | BDI |
| Gnanaraj et al 42 (2015) | India | Prospective | 143 | 21 | 34 | Moderate to severe | Before versus after | 0.5 mg/(kg⋅d) | 3 months | HRS |
| Suarez et al 43 (2016) | Venezuela | Prospective | 36 | 21 | 44 | Severe (25%) | Before versus after | 30 mg/d | 3 months | ZDS |
AGS, Acne Grading scale; BDI, Beck Depression Inventory; CES-D, Centre for Epidemiologic Studies Depression Scale; HADS-D, Hospital Anxiety and Depression Scale-Depression; HRS, Hamilton Rating Scale; ICD, International Classification of Diseases; MADRS, Montgomery-Asberg Depression Rating Scale; NA, not available; ZDS, Zung Self-Rating Depression Scale.