Cognitive Remediation and Transcranial Direct Current Stimulation in Severe Mental Illness (SMI)

Seven per cent of patients suffering from severe mental illness (SMI) need long-term intensive treatment and support in a clinical setting or sheltered living. These service users often experience problems on multiple domains, such as persistent complaints as a result of medication resistance, physical health problems and self-care, psychosocial and cognitive dysfunctioning. Cognitive remediation (CR) training is a type of training aimed at improving thinking abilities (cognitive functioning) and daily functioning. However, we don't yet know if CR training can also help people with SMI who need supported housing due to their severe cognitive and daily living problems. In this project, we are investigating whether we can improve daily functioning in this group by using a form of CR training that focuses on learning new cognitive skills and how to use these new skills in everyday life. Additionally, we are exploring whether combining CR training with mild brain stimulation (transcranial Direct Current Stimulation) can enhance the effects of CR training.

A fundamental challenge for many people with severe mental illness (SMI) is dealing with the impact of cognitive impairments in daily life functioning. A possible treatment approach is cognitive remediation training (CR), a training developed to target cognitive deficits with the ultimate aim to improve daily functioning. Participants engage in cognitive exercises, learn more about their own cognition and the use of (cognitive) strategies to compensate for deficits. However, in people with SMI, abnormal synaptic plasticity is observed. This might hinder newly learned cognitive skills to sustain and limit the benefits from CR. For this reason, people with SMI may benefit from the combination of CR with a method that may promote neural plasticity: transcranial direct current stimulation (tDCS). In a pragmatic, triple-blinded, randomized, sham-controlled, multi-center trial with a multiple baseline design, we will investigate the effectiveness of combining CR and tDCS in helping participants reach personal goals, minimizing problems in daily functioning and improving cognitive functioning. 126 service users with SMI will receive 16-20 weeks of twice-weekly CR combined with active (N=63) or sham tDCS (N=63). We will perform functional, cognitive, and clinical outcome assessments at baseline, after a 16-week waiting period, post-treatment and 6-months post-treatment and compare the effects within-participants (waiting period vs. treatment period) and between-participants (CR+active tDCS vs. CR+sham tDCS). Further, an optional in-depth interview will be conducted post-intervention (T2) to investigate subjective experiences of CR and its perceived effect on metacognition, daily functioning, helpful components, and areas for improvement. This multi-center trial will evaluate whether CR on its own and whether CR in combination with tDCS can be a clinically relevant addition to further enhance recovery through enhancing service users' goal attainment, daily functioning and cognitive performance. In case results of this trial confirm our hypotheses, it may be recommended to include the combined information in the guidelines for SMI care and to implement the method in standardized care.