Table 1 Characteristics of the included RCTs of SAMe in MDD

Caruso 1984 [36]

SAMe vs PBO

3 weeks

200 mg/day

IM

HAM-D (21 items)

Not specified

Kagan 1990 [37]

SAMe vs PBO

3 weeks

200 mg/day

OR

HAM-D (21 items)

DSM-III

Berlanga 1992 [38]

SAMe + IMI vs PBO + IMI

2 weeks

200 mg/day

IM

HAM-D (17 items)

DSM-III-R

Papakostas 2010 [39]

SAMe + SRI vs PBO + SRI

6 weeks

800 mg/day

OR

HAM-D

DSM-IV

Delle Chiaie 2002a [40]

SAMe vs IMI

6 weeks

1600 mg/day

OR

HAM-D (21 items)

DSM-IV

Delle Chiaie 2002b [40]

SAMe vs IMI

4 weeks

400 mg/day

IM

HAM-D (21 items)

DSM-IV

Mischoulon 2014a [41]

SAMe vs PBO

12 weeks

1600–3200 mg/day

OR

HAM-D (17 items)

IDS-C ≥ 25

Mischoulon 2014b [41]

SAMe vs EST

12 weeks

1600–3200 mg/day

OR

HAM-D (17 items)

IDS-C ≥ 25

Sarris 2014a [42]

SAMe vs PBO

12 weeks

1600 mg/day

OR

HAM-D (17 items)

DSM-IV

Sarris 2014b [42]

SAMe vs EST

12 weeks

1600 mg/day

OR

HAM-D (17 items)

DSM-IV

Sarris 2018 [43]

SAMe vs PBO

8 weeks

800 mg/day

OR

MADRS

DSM-V