Abstract
Background
Cognitive impairments in schizophrenia share considerable overlap with those seen in traumatic brain injury (TBI). This overlap offers a rationale for investigating whether cognitive remediation strategies developed for TBI can be tailored to benefit schizophrenia.
Purpose
This exploratory study assessed the efficacy and generalisability of the Brainwave-R cognitive remediation programme, designed initially for TBI, in improving neuropsychological functioning and symptom dimensions in individuals with schizophrenia.
Methods
This was a tertiary Psychiatric Care Facility-based exploratory study following the pre-and-post intervention with a control group (CG) design. Twenty hospitalised male patients diagnosed with schizophrenia were purposively sampled and divided into intervention and CGs (n = 10 each). Participants were assessed pre- and post-intervention using the Luria-Nebraska Neuropsychological Battery and the Positive and Negative Syndrome Scale. Mann–Whitney U tests were employed to compare the effect size of the intervention between groups.
Results
The intervention group exhibited statistically significant improvements across a broad range of neuropsychological domains. Additionally, significant reductions were observed in negative and select positive symptom scores, highlighting the programme’s multidimensional clinical impact.
Conclusion
This study provides promising preliminary evidence for the cross-diagnostic applicability of TBI-based cognitive remediation in schizophrenia. However, the findings must be interpreted cautiously due to key limitations: small, all-male sample size; short intervention duration; and absence of long-term or functional outcome assessments. Future research should prioritise larger, gender-diverse, and longitudinal designs to establish the broader utility and personalisation of cognitive interventions in schizophrenia.
Introduction
While psychotic disorders are not a common result of all traumatic brain injuries (TBI), 1 the neurochemical consequences of head trauma 2 show notable similarities to those seen in schizophrenia. 3 Beyond the direct damage TBI inflicts on distributed neural networks that support higher-order cognition, the injury also disrupts the regulation and availability of several major neurotransmitters. 4 Such neurochemical imbalances can interfere with fundamental cognitive mechanisms. Given these alterations, it is not surprising that the cognitive profiles of individuals with TBI and those with schizophrenia often overlap. A growing body of evidence points to parallel impairments across both groups, most consistently in the domains of attention, memory, and executive functioning.
Research from both cognitive studies and neuroimaging has repeatedly linked abnormalities in frontal lobe functioning—and the consequent executive impairments—to schizophrenia 5 as well as to TBI. 6 Some investigators have proposed that these shared deficits may arise from a similar underlying mechanism, specifically a disruption in reticulo-frontal pathways, which could account for the executive difficulties observed in both conditions. 7
In their 2004 study, Fujii and colleagues 8 administered standard neuropsychological tests to TBI patients with and without psychosis, as well as to a schizophrenia cohort. The absence of significant differences across these groups supports the notion that TBI-related cognitive deficits often resemble those seen in schizophrenia, and similar impairments have been noted in people with TBI, regardless of the presence or absence of post-traumatic psychosis. In a later investigation, Michael and colleagues (2014) employed a computerised assessment to examine specific aspects of attention, including orienting, interference control, and the ability to divide attention. 9 Although disturbances in orienting and divided attention were comparable in both schizophrenia and TBI populations, a marked reduction in interference control was observed exclusively among TBI patients.
The pervasive detrimental effect that similar deficits exert in closed head injury suggests that their impact has probably been underestimated in schizophrenia. It is still uncertain whether the remaining cognitive deficits can be improved, as this question requires direct empirical investigation. Part of the scepticism surrounding the possibility of modifying cognitive deficits in schizophrenia stems from the assumption that these deficits are stable, hereditary vulnerabilities linked to the disorder 10 or a biological mechanism underlying the emergence of negative symptoms. 11 If this premise is accurate, then achieving substantial recovery would depend on approaches capable of modifying these persistent vulnerabilities and lessening their lasting effects.
Because current treatments do not fully address the underlying cognitive disturbances, these impairments continue to hinder comprehensive recovery from schizophrenia. Patients who show improvement in other symptom areas nonetheless struggle with the everyday consequences of cognitive dysfunction, affecting work and social performance, life satisfaction, family stress, and their ability to respond effectively to therapy. Compensatory cognitive techniques may help manage or lessen the influence of these cognitive weaknesses. While the exact nature of an effective intervention is still uncertain, pursuing such efforts is certainly justified.
Methods
Study Design
This was a facility-based exploratory study following the pre-and-post intervention with a control group (CG) design.
Sample
This study was conducted at a tertiary Psychiatric Care Facility located in the eastern part of India. Patients were selected following the recruitment criteria. Right-handed patients of schizophrenia diagnosed according to the Clinical Description and Diagnostic Requirements of International Classification of Diseases-11, 12 in the age group of 25–45 years, with minimum schooling of middle-class standard and five years or more of illness duration, having significant cognitive deficits, on the maintenance dose of anti-psychotic medication, providing informed consent, were included. Individuals showing marked psychopathology, limited ability to understand study instructions, or any form of visual or hearing impairment were not considered for participation. Additionally, to minimise potential confounding influences on cognitive performance, those with a history of substance use, intellectual disability, significant medical conditions, or other organic disorders were excluded. All participants were evaluated using the Positive and Negative Syndrome Scale (PANSS) along with the Hand Preference Battery. Participants were first recruited using purposive sampling based on eligibility criteria. Thereafter, random assignment was conducted using a computer-generated randomisation sequence, prepared by an independent research assistant. Allocation was concealed using sequentially numbered, opaque, sealed envelopes to ensure transparency and reproducibility. A total of 30 individuals were screened for participation, among whom 10 did not satisfy the eligibility requirements. The remaining 20 qualified participants were randomly assigned to either the intervention group (IG) (n = 10) or the CG (n = 10). All participants adhered to their assigned conditions, with no attrition or missing follow-up data. Consequently, all 20 individuals completed the study and were included in the final analyses. The two groups were comparable in terms of socio-demographic characteristics, clinical profiles, neuropsychological measures, and medication status. The mean ages for the IG and CG were 31 ± 2.92 years and 29.60 ± 3.43 years, respectively. All of the participants were male. In both groups majority of the patients were married, Hindu by religion, unemployed, from a semi-urban background, of middle socio-economic status and were residing in a nuclear family. Most of the participants’ income was less than 5,000 rupees per month. The mean age at illness onset for the IG and CGs was 25.50 ± 3.24 years and 25.50 ± 3.24 years, respectively. The mean duration of illness (in years) for the IG and CG was 5.80 ± 0.78 years and 5.80 ± 0.91 years, respectively. Comparison between the groups regarding mode of onset and course of illness shows no significant differences. The majority of participants in both groups exhibited an insidious onset of illness, with a continuous progression thereafter.
Tools
Socio-demographic and Clinical Data Sheet
A semi-structured proforma, developed for the purposes of this study, was employed to obtain comprehensive participant data. The instrument systematically documented socio-demographic parameters—including age, sex, religious affiliation, educational attainment, marital status, residential background, and occupational status. It further incorporated an extensive clinical profile, capturing variables such as the age and mode of illness onset, longitudinal course and duration of the disorder, current pharmacotherapy and associated adverse effects, and history of alcohol or substance misuse. Additional sections addressed familial psychiatric morbidity and documented any significant neurological or medical antecedents, including prior TBI, seizure episodes, intellectual developmental disorder, and other notable physical, organic, or psychiatric conditions that could influence the clinical presentation or cognitive outcomes.
Hand Preference Battery
The assessment developed by Annett (1970) includes six performance items designed to evaluate hand preference. A consistent right-hand response across all items designates right-handedness; similarly, exclusive left-hand use indicates left-handedness. Any combination of right- and left-hand use across the tasks is taken to represent mixed handedness. 13
Positive and Negative Syndrome Scale (PANSS)
Created by Kay et al. (1987), this Scale serves as a standardised measure for quantifying symptom severity in schizophrenia. This 30-item rating scale captures multiple symptom domains, including positive and negative features as well as broader psychopathological manifestations. 14 Internal consistency estimates, based on alpha coefficients, revealed robust reliability and item coherence, with values between 0.73 and 0.83 for each subscale. The first seven items [Delusions (P1), Conceptual Disorganisation (P2), Hallucinatory Behaviour (P3), Excitement (P4), Grandiosity (P5), Suspiciousness/Persecution (P6), Hostility (P7)] are grouped to form a positive scale which measures symptoms that are super added to a normal mental status and The next seven items—Blunted Affect (N1), Emotional Withdrawal (N2), Poor Rapport (N3), Passive/Apathetic Social Withdrawal (N4), Difficulty in Abstract Thinking (N5), Lack of Spontaneity and Flow of Conversation (N6), and Stereotyped Thinking (N7)—comprise the negative symptom subscale, which evaluates deficits not typically present in a normal mental state. The remaining 16 items form the General Psychopathology Scale and provide an index of the overall severity of schizophrenia. Each item is scored on a seven-point scale, with higher ratings indicating greater levels of psychopathology.
Luria-Nebraska Neuropsychological Battery (LNNB-Form 1)
Developed by Golden and colleagues (1985), LNNB is a comprehensive neuropsychological assessment battery intended to evaluate multiple domains of brain functioning. The instrument contains 269 items, which are systematically organised according to the underlying functional constructs into 11 clinical scales, five summary indices, eight localisation scales, and 28 factor-derived dimensions. The clinical scales—Motor (C1), Rhythm (C2), Tactile (C3), Visual (C4), Receptive Speech (C5), Expressive Speech (C6), Writing (C7), Reading (C8), Arithmetic (C9), Memory (C10), and Intellectual Processes (C11)—represent the core components of the battery and measure a wide spectrum of sensorimotor, perceptual, linguistic, and cognitive processes. The summary scales offer higher-order interpretive information, including differentiation between neurologically intact and brain-injured individuals, estimation of impairment severity, and indicators of functional lateralisation. 15
The LNNB has strong empirical support for both its construct and concurrent validity. Research on its reliability indicates solid internal consistency coefficients between 0.78 and 0.94, split-half reliability values ranging from 0.89 to 0.98, test–retest reliability spanning 0.69 to 0.96, and inter-rater reliability between 0.75 and 0.97. The materials included in Form-I (WPS Catalogue Number WX-5) comprise all stimulus cards—those originally created by Anne-Lise Christensen, as well as seven additional cards—along with pressure-sensitive labels and an audio cassette used for administering the C2 scale. Each stimulus card is marked with a specific letter–number code, which corresponds with the designations provided in the manual.
The Cognitive Rehabilitation Package for Intervention
The Brainwave-R cognitive rehabilitation programme, originally developed for TBI 16 was adapted for this study. The Brainwave-R modules were modified to suit schizophrenia-specific cognitive deficits. Cultural adaptations included simplifying instructions, incorporating contextually familiar stimuli, and adjusting task difficulty to accommodate variability in symptom severity. Clinical adaptations included shorter session durations, enhanced scaffolding, and additional therapist-guided prompts to maintain engagement. The intervention was delivered individually over 60 sessions, with each session lasting approximately 30–40 minutes per day, except weekends, for 12 weeks. Hence, the average total duration of intervention per individual was approximately 45 hours.
Each session was structured in the following order as brief orientation to cognitive training, an introduction and rationale for new tasks, a discussion of task steps, task demonstration, guided practice, error correction, feedback, homework assignment, and assessment. Patients were reminded to attend regularly, maintain a task notebook, and report any difficulties.
The programme consisted of three modules: attention, memory, and executive function. The attention module targeted focused, sustained, selective, alternating, and divided attention with progressive difficulty and speed. The memory module emphasised educational and compensatory strategies, addressing attention, organisation, and information processing to manage deficits, especially in declarative memory. The executive function module provided structured strategies for routines, goal planning, and problem-solving.
Procedure
Thirty patients with schizophrenia (diagnosed according to the CDDR of ICD-11, 2024) were interviewed and screened from the male wards of the Care Facility. A total of 20 patients who satisfied the predetermined inclusion and exclusion parameters were selected after initial screening procedures. All subjects provided signed informed consent prior to enrolment. The investigation was carried out in full compliance with ethical guidelines articulated in the Declaration of Helsinki.
Clinical interview and required history were collected from the patient and the case record file. Socio-demographic and Clinical Data Sheet were filled for initial information. Annett’s Hand Preference Battery was used to decide handedness. Baseline assessment of all the patients was done. The Positive and Negative Syndrome Scale (PANSS) was administered to assess symptom severity. LNNB: Form I was used to assess neuropsychological functioning.
After baseline assessment, the drawn sample was randomly divided into two groups- Group A (IG) and Group B (CG), with 10 patients in each group. Both groups received a standardised, two-session psychoeducation module covering illness understanding, symptom management, medication adherence, and coping skills, along with routine therapeutic intervention (group meeting and pharmacotherapy). Sessions were delivered using a brief manual to ensure consistency. However, only the IG received the cognitive rehabilitation programme, in addition, for 12 weeks. The training programme was tailored according to the needs of the individual. All intervention sessions were delivered by a trained professional, and fidelity was maintained through weekly supervision meetings with a senior supervisor. A structured intervention checklist was used to monitor consistency across sessions. Patients were re-assessed after completion of 12 weeks of training.
Statistical Analysis
Data were analysed using the Statistical Package for the Social Sciences, version 28 (SPSS-28). The Mann–Whitney U test was employed to compare the control and experimental groups on continuous socio-demographic variables such as age and duration of illness, while chi-square analyses were used for categorical socio-demographic variables. Baseline comparisons of clinical symptoms and neuropsychological performance between the two groups were also conducted using the Mann–Whitney U test. Following the intervention, the same nonparametric test was applied to assess differences in pre- to post-intervention change scores for clinical and neuropsychological outcomes across the groups.
Results
Table 1 shows a comparison of neuropsychological performance between IG and CG at baseline. It shows that there was no significant difference between the IG and CG on most of the domains of neuropsychological functions, with group equivalence (r) ≤ 0.39. However, the groups differed significantly in their reading (p < .01; r = 0.47), writing (p < .05; r = 0.50) abilities and expressive speech (p < .05; r = 0.71). The table further shows a comparison of differences in neuropsychological performance between IG and CG due to intervention. It shows that the neuropsychological performance of the IG after intervention was significantly better than that of the CG. These differences were significant at the 0.01 level for all the elements of neuropsychological performance with an effect size (r) ≥ 0.50.
Comparison of Neuropsychological Performance.
Comparison of Negative Symptoms.
Comparison of Positive Symptoms.
Discussion
On the baseline assessment with the LNNB, both the IG and CG were found to have a generalised impairment across most of the neuropsychological domains assessed. This impairment was more pronounced in some domains, that is, Motor Functions, Tactile Functions, Visual Functions, Expressive Speech, Arithmetic, Memory and Intellectual Functions. On baseline assessment, both IG and CG were found to be comparable across most of the neuropsychological function domains. However, a statistically significant difference was found in the domains of expressive speech, writing and reading.
In terms of efficacy of the cognitive rehabilitation programme, results of the statistical analysis show that significant differences were found across all the neuropsychological function domains in favour of the IG. Whereas, Rhythm, writing and Arithmetic improved at the 0.05 level. The reason for the lesser improvement in these functions may be the complex abilities involved in their performance. Since Rhythm and Arithmetic are functions requiring long-term practice, the three-month rehabilitation programme may not been sufficient for improvement of these finer functions. Since the rehabilitation programme used in the present study was focused on the three core cognitive functions, that is, Attention, Memory, and executive functions, the improvement being observed in other neuropsychological functions is quite encouraging. The reason for this may be that attention, memory and executive functions are the basic and core cognitive functions, and many authors have suggested that the generalised impairment in most of the neuropsychological functions characteristic of schizophrenia may be due to an initial impairment in these basic cognitive skills. Hence, remediation attempts at these core skills should bring improvement in other functions, and the same is being observed in the results of the present study.
Some of these functions, namely, expressive speech, reading and writing, were found to differ significantly between the two groups at the baseline. However, when comparing the effect size of the intervention, the differences found in expressive speech, reading and writing for the IG were 24.90 ± 7.46, 8.60 ± 1.95 and 9.0 ± 2.35, respectively, in comparison to 4.30 ± 2.98, 0.10 ± 1.28 and 1.90 ± 1.28 for the CG. These differences in the neuropsychological functioning of the IG may be assumed to have occurred because of the intervention, but certainly not because of the sample characteristics. These results prove the efficacy of the cognitive rehabilitation programme used in the present study.
Whereas many studies have documented memory deficits in schizophrenia, relatively few studies have investigated the remediation of these deficits. Most of the remediation efforts in this domain have been focused on working memory.17, 18 The present study is the first of its kind, as, along with working memory, most of the other memory subsystems have also been focused. Another issue has been the disappearance of the remediation effects for tasks other than the training task. Many authors have reported failure to generalise the remediation skills to tasks other than the training task.18, 19 The results of the present study suggest that the remediation effects were generalised to tasks other than the training task, and a significantly improved performance was seen on the memory scale of the LNNB after remediation training with the memory module of the Brainwave-R.
Likewise, in the area of executive functioning, numerous investigations have examined whether performance on the WCST can be improved through targeted training. A major shortcoming of this research is that, in most instances, the same tool used for training is also used to assess the outcome, limiting the interpretability of the results. In contrast, the present study demonstrated that engaging patients in the executive function module of the Brainwave-R led to measurable gains on the LNNB, a measure on which they had not previously been trained.
There have been very few studies undertaking remediation of other neuropsychological functions in schizophrenia patients, namely motor functions, rhythm, expressive and receptive speech, reading, writing, etc. However, some impairment has been noticed in these domains, also on items requiring higher-order skills. The findings of the present study show that these functions have also improved significantly from the baseline because of the remediation training. This further shows that remediation of core cognitive deficits in the domains of attention, memory, and executive functions can produce changes in other neuropsychological functions. This is another line of evidence for the efficacy of the cognitive rehabilitation programme used in the present study.
Comparison of differences in negative symptoms between IG and CGs after intervention shows that a statistically significant difference (p < .01) was found for all the subdimensions of the negative symptoms subscale. These findings indicate the excellent generalisability of the cognitive rehabilitation programme used in the present study. Researchers have studied the relationship between psychopathology and cognitive functioning in schizophrenia and found that remediation programmes showed significant and persistent improvement on subscales of PANSS. 20 However, the results of the study done by Bell and Mishara (2006) are contrary to the findings of the present and previous studies. 21 Analysis of the study design shows that the remediation programme used in that study consisted of more strategies for work rehabilitation and very few strategies for cognitive rehabilitation. Hence, there was a change seen in functional outcomes, but these could not be generalised to neurocognitive or negative symptoms because these were not the main targeted skills. However, the present study and previous studies which have provided remediation for core cognitive skills report a significant improvement in negative symptoms also.
Statistically significant differences were observed in most of the subdimensions of the positive symptoms scale of PANSS, namely Delusion, hallucinatory behaviour, excitement, suspiciousness and total score when both the groups were compared after intervention for positive symptoms. However, no significant difference was found in some areas, namely, conceptual disorganisation, grandiosity and hostility. Since we have already seen in the previous section discussing the neuropsychological performance of the patients that concept formation could not be remediated with the intervention programme used in the present study. There is a need to use a cognitive remediation programme of longer duration to remediate such higher-order skills. Further, since the main line of treatment for grandiosity and hostility has been pharmacology, improvement in these symptoms cannot be expected from cognitive remediation. Results of the present study regarding generalisation of cognitive rehabilitation to positive symptoms have also been reported by various previous studies.22, 23
There are a few noteworthy factors limiting the generalisability of the findings of the present study. The study is limited by its small sample size, employing 20 subjects in total and only 10 in the IG. Hence, the findings should be interpreted cautiously and serve as preliminary evidence guiding future, larger-scale studies. The study sample consisted of all male subjects without any participation of female representatives. The duration of the intervention was around three months and relatively short. There was no long-term follow-up, which constrained the generalisability and durability of findings. Also, outcome assessors were not blinded due to logistical constraints and the limited research staff available. Hence, future studies should incorporate blinded assessment procedures. Though utmost care was taken to interpret the test and intervention instructions, Cultural mismatch in test and intervention package standardisation may have had some effects on the study findings. Unavailability of real-world functional outcome measures further limit external applicability of the study findings.
Conclusion
The current findings add to an expanding body of research suggesting that cognitive remediation can be a valuable addition to managing schizophrenia, especially when adapted from successful models used in TBI rehabilitation. Historically, clinical neuropsychology aimed to differentiate between psychotic and brain-injured populations, a goal that proved largely unproductive. 24 Ironically, it is now the shared cognitive impairment patterns and their responsiveness to similar remediation strategies that show the most promise. 25 Future studies should aim for larger and more diverse samples featuring demographic and syndromal diversity. Provisions of longer training durations, and inclusion of functional and follow-up assessments may extend and validate these promising results better.
Footnotes
Abbreviations
LNNB = Luria–Nebraska neuropsychological battery
PANSS = Positive and Negative Syndrome Scale
TBI = Traumatic brain injury
Acknowledgements
Our sincere thanks go to all individuals whose assistance and encouragement facilitated the completion of this research. Their contributions, both explicit and behind the scenes, were vital to this endeavour. We are equally grateful to the study participants for their cooperation and for generously offering their time and insights, which formed the foundation of our data.
Authors’ Contribution
Conceptualisation: Sarika Alreja Mishra; Methodology: Sarika Alreja Mishra, Deepak Mishra; Formal analysis and investigation: Deepak Mishra, Sarika Alreja Mishra; Writing ‐ original draft preparation: Sarika Alreja Mishra; Writing ‐ review and editing: Deepak Mishra; Resources: Deepak Mishra, Sarika Alreja Mishra; Supervision: Deepak Mishra.
Declaration of Conflict of Interests
The authors declared no potential conflicts of interest with respect to the research, authorship and/or publication of this article.
Funding
The authors received no financial support for the research, authorship and/or publication of this article.
Patient Consent
All participants provided written informed consent prior to enrolment in the study.
Statement of Ethics
The research protocol was approved by the Institutional Review Board (IRB) of the P.G. Department of Psychology, Ranchi University, Ranchi, Jharkhand, India. This research was conducted ethically in accordance with the World Medical Association Declaration of Helsinki.
