Combining compensatory cognitive training and medication self-management skills training, in inpatients with schizophrenia: A three-arm parallel, single-blind, randomized controlled trial

Highlights

• CCT had improvements in verbal fluency, total cognitive function and medication adherence compared with the TAU.

• CCT + MSST had improvements in verbal fluency and total cognitive function compared with the TAU.

• CCT + MSST had improvements in positive symptoms and medication adherence compared with the TAU.

• CCT + MSST had improvements in total cognitive function compared with the CCT.

Abstract

Objective

Cognitive impairment has a critical impact on functional outcomes in patients with schizophrenia. Compensatory cognitive training (CCT) has shown promise as a cognitive rehabilitation tool but little is known about its effectiveness when combined with medication self-management skills training (MSST) in patients with schizophrenia. Thus, this study compared the effects of a combined CCT and MSST with CCT and treatment as usual (TAU) on cognitive function, symptoms, and medication adherence.

Method

Eighty-seven inpatients with schizophrenia were randomly assigned to the TAU, CCT, or CCT + MSST groups. Assessments of cognitive function using the Brief Assessment of Cognition in Schizophrenia, symptoms using the Positive and Negative Syndrome Scale, and medication adherence using the Medication Adherence Questionnaire, were administered to all participants at baseline and at post-intervention.

Results

Compared with the TAU group, the CCT group had significant improvements in verbal fluency, total cognitive function and medication adherence, and the CCT + MSST group had significant improvements in verbal fluency, total cognitive function, positive symptoms, and medication adherence. Compared with the CCT group, the CCT + MSST group had significant improvements in total cognitive function.

Conclusions

These results indicate that the integrated intervention may be more advantageous than CCT alone in improving total cognitive function and positive symptoms. Future research should seek to further explore the long-term effects of such a joint intervention.

Introduction

Cognitive impairment is a key feature of schizophrenia. Most patients with schizophrenia experience significant cognitive impairments, especially in working memory, executive functions, processing speed, attention/vigilance, verbal learning and memory [1]. These cognitive domains are key predictors for functional outcomes [2] and degree of disability [3]. Some meta-analyses provided evidences that cognitive remediation treatment was effective in improving cognitive function in patients with schizophrenia [4,5]. Therefore, cognitive remediation therapy is crucial to improve functional outcomes and quality of life in patients with schizophrenia.

Recently, cognitive remediation strategies were categorized into two main models: “restorative” and “compensatory” [6]. The “restorative” model focuses on correcting cognition impairments by training on specific cognitive tasks, whereas the “compensatory” model focuses on reducing dependence on cognitive function by utilizing residual cognitive functions or other environmental resources. Although “restorative” treatments have been shown to have small-to-moderate effects in improving cognitive function in patients with schizophrenia, the effects of “restorative” treatments on functional outcomes and symptoms are variable [4,5,7]. It has been observed that unless the “restorative” approaches was integrated into broader psychiatric rehabilitation interventions such as neuropsychological educational approach [8], or real world simulations and goal setting [9], impacts on functional outcomes and symptoms are less robust. The “compensatory” approaches not only improve cognitive function, but also improve adaptive function and symptoms [10,11]. There are two reasons for this phenomenon. First, compensatory strategies improve patient's adaptive function at home and work environments by behavioral sequencing and utilizing environmental resources including signs and labels [12], which may contribute to improving social problem-solving ability and promoting the maintenance of social activities. Second, as these strategies gradually develop into daily habits, patients become more confident in performing activities they tried to avoid previously, thus leading to an improvement in patients' negative symptoms [13]. Furthermore, the “compensatory” approaches can become lifelong habits that can help patients to reduce their dependence on residual cognitive function, which may contribute to improving functional outcomes and psychiatric symptoms in patients with schizophrenia.

Compensatory cognitive training (CCT) is a form of “compensatory” treatment for cognitive impairments in patients with psychosis and targets four cognitive domains that were selected based on strong correlations between these cognitive domains and functional outcomes, as well as their potential modifiability [14,15]: 1) cognitive flexibility and problem-solving; 2) prospective memory; 3) verbal learning and memory; and 4) attention. The core of CCT is to teach patients to master the “compensation” strategies and form new habits to reduce the cognitive burden in daily life [16]. Research showed that CCT improved attention, verbal memory, negative symptoms, functional skills, and quality of life in patients with psychosis at the 3-month follow-up [17]. Another study showed that CCT had moderate-to-large effects on working memory, depressive symptom, and quality of life in patients with severe mental illnesses at the post-treatment [18].

Although several studies have provided promising results regarding CCT, the effects of CCT combined with medication adherence training on cognitive function in patients with schizophrenia need further research. One potential reason for this is that the neurodegenerative course in some dysfunctional brain regions in schizophrenia was related to relapse [19], and medication adherence has been implicated as the key predictor of psychiatric symptoms in patients with schizophrenia [20]. Approximately half of all the patients with schizophrenia experienced a relapse and were hospitalized due to poor medication adherence [21]. McGurk et al. indicated that the addition of cognitive remediation to supported employment led to a significant increase in cognitive and work functioning in patients with serious mental illness, compared to supported employment alone [22]. Kukla et al. also suggested that combining cognitive remediation and vocational intervention program resulted in a significant increase in work functioning and total cognitive function in patients with schizophrenia spectrum disorders, compared to cognitive remediation therapy alone [23]. Therefore, we speculate that the implementation of the combined CCT and medication adherence training may improve better cognitive function in patients with schizophrenia, compared to CCT alone.

Medication adherence in patients with schizophrenia was also associated with patients' knowledge about prescribed antipsychotics, and positive attitude toward medication [24]. Liberman and Glick compiled medication self-management skills training (MSST) for key factors impacting medication adherence, which include knowledge about the role of antipsychotics, self-management and effect evaluation of antipsychotics, identification and dispose of side effects, and negotiation of medication issues with medical staff [25]. Although previous studies have indicated that MSST is effective in improving medication adherence and reducing symptom severity in patients with schizophrenia after discharge [26,27], the effects of CCT combined with MSST on cognitive function are unknown. Therefore, we investigated the effects of a comprehensive intervention by comparing the effects of CCT and MSST combined with CCT alone, and each, compared with treatment as usual (TAU) on cognitive function, symptoms, and medication adherence at baseline and at post-intervention. We hypothesized that CCT, compared to TAU, would improve cognitive function, psychiatric symptoms, and medication adherence; and that an intervention integrating CCT and MSST, compared to CCT alone, would improve better cognitive function, medication adherence, and psychiatric symptoms in patients with schizophrenia.