Table 4.

Key findings.

References	Study aim(s)	Key finding(s)
Godfrey et al. (1985)	Evaluate long-term memory improvements in participants having as a base an intensive memory rehabilitation program for amnesic alcoholics	Both the memory training group and the active control group showed improved memory function in the post-test. There is no information about a statistical comparison between the groups in order to examine possible differences.
Godfrey and Knight (1985)	Understand whether the memory function can be generalized to other memory functioning tasks and determine the duration of maintenance of the gains in question	The control group showed the same benefits in memory performance as the experimental group.
Yohman et al. (1988)	Determine whether the neuropsychological areas involved in patients with alcoholism who undergo cognitive training have improved compared with individuals who have not received any type of training; understand whether other cognitive areas can benefit from training, even if it is specific to a certain area	The problem-solving group showed improvements in the results of the problem-solving tests compared with the group that did not receive any training. However, the problem-solving group did not show increase in terms of memory and in perceptual-motor skills.
Hannon et al. (1989)	Examine the effectiveness of memory retraining in individuals with alcohol problems	The results did not show sufficient support to confirm the objective of the study. Only the Memory Matrix Test showed gains between the pre- and the post-test.
Wetzig and Hardin (1990)	Understand whether cognitive retraining impacts a sample of individuals with SUD and cognitive impairment	Individuals who received remedial training achieved an equal and superior performance on the Wisconsin Card Sorting Test than the general population.
Steingass et al. (1994)	Determine whether semantically encoded material is favored by the treatment	The experimental group that received treatment showed improvements in terms of reproduction of figures and verbal memory.
Fals-Stewart and Lucente (1994)	Based on a cognitive rehabilitation program, evaluate whether there are neuropsychological changes in a sample of individuals with drug use and the presence of cognitive deficits	During the first 2 months of treatment, patients who received the cognitive rehabilitation program showed gains in cognitive functioning: Cerebral recovery was faster in these patients.
Peterson et al. (2002)	Investigate the efficacy of the NeurXerciseTM program, which concerns a computerized cognitive remediation program, within the scope of cognitive recovery	The effectiveness of the computerized cognitive remediation program used in the study was not confirmed. There were no statistically significant differences between the group that received the program, the placebo group, and the group without intervention.
Goldstein et al. (2005)	Investigate the effectiveness of a cognitive training program in order to benefit the cognitive functioning of individuals with alcohol use disorder and comorbidities with other neuropsychiatric disorders, namely in the subacute phase of detoxification	There were cognitive increases in the experimental group compared to the placebo group, namely in the conceptual flexibility and attention.
Fals-Stewart and Lam (2010)	Evaluate whether patients in the experimental group who received standard treatment plus computer-assisted cognitive rehabilitation, compared with a control group who received an intensive care program, showed better results in cognitive functioning	The group with standard treatment plus computer-assisted cognitive rehabilitation showed a faster overall improvement in cognitive functioning compared to the control group. However, it was not possible to determine whether these improvements were differential for the various cognitive functions.
Rupp et al. (2012)	Assess whether cognitive remediation therapy during treatment improves cognitive functioning in patients with alcohol use disorder.	The group that received cognitive remediation therapy showed significant increment in memory, executive functioning and care, especially in WM delayed memory and attention (divided attention and alertness). Improvements were also noted in the Mini Mental State Examination and Complex Figure Test indices.
Gamito et al. (2013)	Evaluate the effect of cognitive stimulation using serious games in a sample of patients with alcohol dependence syndrome	There were improvements in the general cognitive functions assessed in all groups. However, there was an improvement in the frontal area in the cognitive functioning of the individuals in the group who received a cognitive stimulation program, using mobile technology.
Gamito et al. (2014)	Evaluate the cognitive effects in a sample of individuals with alcohol dependence based on a neuropsychological intervention using serious games and mobile technology	There was an increase in general cognitive skills, both in the control group and in the experimental group. However, the improvement was more significant in terms of frontal lobe functions in the experimental group. Processing speed was evaluated using two versions of the Color Trail Test (CTT). Although there was a decrease in the error rate and execution time of CTT1 and CTT2, there was no statistically significant interaction in terms of the treatment factor.
Eack et al. (2015)	Evaluate the efficacy and feasibility of using Cognitive Enhancement Therapy in a sample of patients with schizophrenia and alcohol/cannabis misuse	Cognitive Enhancement Therapy was an effective and viable treatment for cognitive impairments in schizophrenic patients with alcohol/cannabis problems. The neurocognitive gains were most evident in verbal learning and processing speed (NIMH MATRICS Consensus Cognitive Battery), although neither showed statistically significant differences.
Rass et al. (2015)	Examine whether WMT brings cognitive changes in a sample of methadone maintenance patients.	The experimental group of methadone maintenance patients achieved improvements in some measures of WM after receiving WMT, namely in visuospatial WM and digit span. However, there were no improvements on WM measures dissimilar from the training tasks.
Bell et al. (2016)	Evaluate the efficacy of cognitive training in memory deficits and verbal learning of older veterans with alcohol use disorder	Cognitive training in conjunction with work therapy was effective in ameliorating memory deficits in a sample of individuals with alcohol use disorder.
Brooks et al. (2016)	Evaluate the effect of standard psychological TAU and adjunct WMT on brain volume in male in-patients receiving treatment for methamphetamine (MA) use.	The control group (TAU) presented larger volume in the bilateral putamen and reduced volume in the left middle temporal gyrus, right post-central gyrus and left insula cortex. The experiemntal group (TAU + WMT) showed more pronounced increases in volume that extended across large areas of the bilateral basal ganglia, along reduced bilateral cerebellar volume. WM accuracy at post-test in the experimental group was associated with larger volume in the right middle frontal cortex and orbitofrontal cortex. While there was an improvement in WM accuracy in the experimental group, no near-transfer effects were found (no changes in the Trail Making Test).
Gamito et al. (2016)	Evaluate the efficacy of a Cognitive Stimulation Program, using mobile devices, related to the cognitive rehabilitation of recovering alcoholic individuals	There was significant benefit in terms of frontal lobe functioning in the experimental group.
Bell et al. (2017)	Test whether the group of individuals who received cognitive remediation therapy and work therapy showed improvements in neurocognitive functions compared with a group that only received work therapy	There were significant differences in the executive functioning indexes in the group that received cognitive remediation therapy and work therapy. There were no statistically significant differences in the rate of change of processing speed between cognitive remediation therapy with work therapy and the work therapy with treatment as usual.
Brooks et al. (2017)	Evaluate the impact of daily WMT alongside treatment as usual (TAU) on self-report measures of impulsivity and self regulation in patients receiving treatment for methamphetamine (MA) use.	From the experimental group (TAU + WMT), those who engaged in the highest level of training had a learning effect of 35% between pre and post-test, and showed significant changes in self-reported impulsivity and self-regulation scores. There were no significant differences in executive measures (Trail Making Test) between pre and pot-test in the experimental group.
Gamito et al. (2017)	Analyze the efficacy of cognitive training in the rehabilitation and stimulation of addicts in recovery, based on a serious games approach	There was an increase in cognitive functioning in terms of frontal brain functions as well as sustained attention and verbal memory. There were also improvements in decision-making and cognitive flexibility.
Gunn et al. (2018)	Examine the efficacy a complex WMT program in those with an alcohol use disorder (AUD), as well as predictors of training improvement.	There was significant transfer on two near WM transfer measures (Rotation Span and Auditory Consonant Trigram) at post-test and 30-day follow-up for individuals who completed the WMT, independent of the group (AUD vs. healthy control). There was also evidence of transfer on one moderate transfer task (Running Spatial Span) at post-test, but not on the 30-day follow-up.
Hendershot et al. (2018)	Assess whether the WMT together with treatment as usual contributes to improvements in executive functioning in the short term	There were marginally significant improvements found in the digit span (primary outcome) and in the results of the Cogmed Progress Indicator index (secondary outcome). There were no other secondary outcome improvements to support the efficacy of WMT.
Zhu et al. (2018)	Understand whether cognitive impairments can be improved based on the Computerized Cognitive Addiction Therapy (CCAT) application	Comparing with the control group, the CCAT group had better cognitive performance after 4 weeks of training as well as better performance on impulsive control tasks.
Khemiri et al. (2019)	Test the efficacy and viability of a WMT program (computerized) in patients with alcohol use disorder	The experimental group saw significant improvements in verbal, but not spacial, WM functioning. No effect of WMT was found on other cognitive functions.
Rezapour et al. (2019)	Evaluate the efficacy of a cognitive rehabilitation treatment with a view to improving the neurocognitive functions of individuals with opioid use disorder	The group of individuals who received cognitive rehabilitation treatment showed significant improvements in terms of processing speed, WM, and memory span. There was also an increase in these individuals in the switching and learning tests. In turn, these effects were shown to persist for at least 6 months.