Table 1 Controlled clinical trials reporting cognitive rehabilitation in adults with MDD

Areann 2016 [37]

132 adults with a PHQ-9 score > 10:

1- Experimental group (n = 56)

2- Control group (n = 76)

1- Experimental group: Project EVO (a cognitive training app)

2- Control group: an app that provided daily health tips

No post-intervention significant difference between groups: P-value = 0.15

Au 2021 [38]

22 patients with MDD:

1- Experimental group (n = 12)

2- Control group (n = 10)

1- Experimental group: occupational therapy and Chinese version of the PM module of the Cognitive

Compensatory Training (CCT-C-PM)

2- Control group: occupational therapy

• ͰDepression anxiety stress scale score (DASS) Group*Time interaction F = 1.35, P = .99

• Cambridge prospective memory test score (CAMPROMPT-C) Group*Time interaction F = 7.97, P = .01

Bowie 2013 [39]

33 patients with treatment resistant MDD:

1- Experimental group (n = 17)

2- Control group (n = 16)

1- Experimental group: cognitive remediation (CR)

2- Control group: wait list

Assessments:

• Attention and processing speed: The symbol coding task, the continuous performance test, controlled oral word association test, Animal naming test, and Trail making test

• Verbal Memory: The Hopkins verbal learning Test

• Executive functioning: The letter number sequencing test, trail making test, and The Stroop color-word test

• Attention and information processing speed Group*Time interaction: F[1, 18] = 7.8, p = 0.012

• Verbal learning and memory Group*Time interaction: F[1, 16] = 6.2, p = 0.023

• Executive functioning Group*Time interaction: F[1, 17] = 0.8, p = 0.38

Ferrari 2021 [40]

115 MDD inpatients:

1- Experimental group (n = 56)

2- Control group (n = 59)

1- Experimental group: Cognitive Control Training (CCT)

2- Control group: comparable sham-training

• The Beck depression inventory (BDI-II) Group*Time interaction: F[1, 107] = 0.04, p = 0.84

• the random number generation task (RNGT) Group*Time interaction: F[3, 108] = 1.91, p = 0.13

Hoorelbeke 2016 [41]

68 patients with remitted MDD:

1- Experimental group (n = 34)

2- Control group (n = 34)

1- Experimental group: Cognitive Control Training (CCT)

2- Control group: a low cognitive load training

• The Beck depression inventory (BDI-II) Group*Time interaction: F[2, 65] = 1.2, p = 0.3

• Remission of depression questionnaire (RDQ) Group*Time interaction: F[1, 66] = 11.21, p = 0.001

• Non-adaptive PASAT accuracy Group*Time interaction: F[1, 66] = 18.52, p < 0.001

Klojčnik 2021 [42]

20 patients with MDD:

1- Experimental group (n = 10)

2- Control group (n = 10)

1- Experimental group: Standard rehabilitation interventions with computerized cognitive remediation (CCRT)

2- Control group: Standard rehabilitation interventions

• The Beck depression inventory (BDI-II) Group*Time interaction: F[1, 18] = 9.92, p = 0.006

• The test for attentional performance (TAP) Group*Time interaction:

Alertness: F[1.18] = 10.57, p = 0.004

Inhibition: F[1.18] = 20.99, p < 0.001

Flexibility: F[1.18] = 9.18, p = 0.007

Divided attention: F[1.18] = 10.18, p = 0.005

• The tower of London (TOL) Group*Time interaction:

Total move score: F[1.18] = 17.16, p = 0.001

Number of correct solutions: F[1.18] = 41.88, p < 0.001

Total problem-solving time: F[1.18] = 18.26, p < 0.001

Total execution time: F[1.18] = 6.38, p = 0.02

• The behavior rating inventory of executive function-adult (BRIEF-A) Group*Time interaction:

Inhibition: F[1.18] = 1.1, p = 0.3

Shift: F[1.18] = 36.07, p < 0.001

Emotional control: F[1.18] = 20.21, p < 0.001

Initiate: F[1.18] = 23.56, p < 0.001

Working memory: F[1.18] = 6.07, p = 0.02

Plan/organize: F[1.18] = 5.39, p = 0.03

Lacoviello 2014 [43]

21 patients with unmedicated MDD:

1- Experimental group (n = 11)

2- Control group (n = 10)

1- Experimental group: The cognitive-emotional training group

2- Control group: Active control group

• The Hamilton depression rating scale (Ham-D) Group*Time interaction: F[1, 19] = 5.6, P = .02

• Unsignificant differences in: Digit-span forward (DSF), Digit-span backward (DSB), and Letter-number sequencing (LNS) subtests of the Wechsler adult intelligence scale

Listunova 2020 [44]

62 patients with partial remission MDD:

1- Experimental group (n = 38)

2- Control group (n = 19)

1- Experimental group: Cognitive remediation therapy (CRT)

2- Control group: Passive control group

Assessments:

• Attention: Alertness, divided attention and selective attention subscales of the test battery of the Vienna test

• Learning and Memory: California verbal learning test (CVLT) and figural memory subscale of the test battery of the Vienna test

• Executive functioning: Trail Making Test-L Version B, Tower of London-F, N-Back-verbal, and inhibition subscale of the test battery of the Vienna test

• Unsignificant differences in: The Hamilton depression rating scale (Ham-D), The Beck depression inventory (BDI-II), information processing speed, executive function, learning and memory

• Attention Group*Time interaction: F[1, 35] = 5.232, p = 0.014

Moshier 2015 [45]

32 adults with a BDI-II score in 16 to 35 range:

1- Experimental group (n = 16)

2- Control group (n = 16)

1- Experimental group: Cognitive Control Training (CCT)

2- Control group: The peripheral vision task

• The Beck depression inventory (BDI-II) Group*Time interaction: F[1.6,60] = 0.64, p = 0.49

• The repeated knob-checking task Group*Time interaction:

Memory accuracy: F[1, 64] = 0.45, p = 0.5

Memory confidence: F[1, 65] = 1.2, p = 0.27

Memory vividness: F[1, 65] = 2.66, p = 0.1

Memory detail: F[1, 65] = 2.67, p = 0.1

Moshier 2017 [46]

34 patients with MDD:

1- Experimental group (n = 17)

2- Control group (n = 17)

1- Experimental group: Computerized cognitive Control Training (CCT)

2- Control group: The peripheral vision task

• Unsignificant differences in the Beck depression inventory (BDI-II)

Semkovska 2015 [47]

24 MDD inpatients:

1- Experimental group (n = 12)

2- Control group (n = 12)

1- Experimental group: Computerized neurocognitive remediation therapy (NCRT)

2- Control group: Computer games

• Unsignificant differences in the Beck depression inventory (BDI-II)

Semkovska 2017 [48]

22 patients with remitted MDD:

1- Experimental group (n = 11)

2- Control group (n = 11)

1- Experimental group: Computerized neurocognitive remediation therapy (NCRT)

2- Control group: Computer games

• The Beck depression inventory (BDI-II) Group*Time interaction: F[1, 19] = 0.31 P = 0.59

• The Hamilton depression rating scale Group*Time interaction: F[1, 19] = 0.003 P = 0.96

• The Selective attention test Group*Time interaction: F[1, 19] = 7.05 P = 0.01

• The digit span backward test Group*Time interaction: F[1, 19] = 11.81 P = 0.003

• The logical memory test Group*Time interaction:

Logical memory-I (total): F[1, 19] = 0.003 P = 0.96

Logical memory-II (retention): F[1, 19] = 14.36 P = 0.001

• The towers of London test Group*Time interaction: F[1, 19] = 26.9 P < 0.001

• The fluency switching test Group*Time interaction: F[1, 19] = 7.24 P = 0.01

Trapp 2016 [49]

41 MDD inpatients:

1- Experimental group (n = 21)

2- Control group (n = 20)

1- Experimental group: Cognitive remediation therapy (CRT)

2- Control group: Passive control group

Assessments:

• Depression: Beck depression inventory and Hamilton depression rating scale

• Memory: visual reproduction II and logical memory II of Wechsler memory scale (WMS)

• Working memory: WMS spatial span forward, WMS spatial span backward, WMS digit span forward, WMS digit span backward, WMS visual reproduction I, and WMS logical memory I

• Attention: Degraded continuous performance test (CPT) omissions, Degraded CPT commissions, and Trail Making Test (TMT) A performance time

• Executive function: WCST total errors, TMT B performance time, and TMT B-A

• Depression Group*Time interaction: F = 2.38 P = 0.13

• Attention Group*Time interaction: F = 0.62 P = 0.6

• Executive function Group*Time interaction: F = 3.14 P = 0.03

• Working memory Group*Time interaction: F = 2.63 P = 0.03

• Memory Group*Time interaction: F = 4.5 P = 0.03

Wanmaker 2014 [50]

61 adults with a BDI-II ≥ 10:

1- Experimental group (n = 34)

2- Control group (n = 27)

1- Experimental group: Working memory training

2- Control group: Video game

• The Beck depression inventory (BDI-II) Group*Time interaction: F[1, 46] = 0.63 P > 0.05

• The span board test Group*Time interaction: F[1, 46] = 8.98 P < 0.01

Wanmaker 2015 [51]

98 MDD patients (with or without anxiety) or GAD patients with at least moderate depressive symptoms (by BDI-II):

1- Experimental group (n = 49)

2- Control group (n = 49)

1- Experimental group: Working memory training

2- Control group: Video game

• The Beck depression inventory (BDI-II) Group*Time interaction: F[1,72] = 0.06 P > 0.05

• The digit forward test Group*Time interaction: F[1, 69] = 1.42 P > 0.05

• The digit backward test Group*Time interaction: F[1, 68] = 4.85 P < 0.05

• The reading span test test Group*Time interaction: F[1, 69] = 4.85 P < 0.05