Cognitive Remediation Therapy (CRT) is a behavioral-training based intervention that aims to improve cognitive processes and psychosocial functioning.
The first records of rehabilitation programs appeared during World War I. The objective was to rehabilitate soldiers with traumatic brain injuries. These techniques were further developed during World War II.
Around 1943, the rehabilitation ideas were extended to psychiatric disabilities. Furthermore, with the deinstitutionalisation movement and the community mental heath care development in the 1950’s and 1960’s, the interest in preventing disability in severe psychiatric diseases also flourished. Attending to the growing evidence of the last decades about the prevalence and impact of cognitive deficits in severe mental illness, the interest in cognitive remediation was stimulated. Relevant studies on Schizophrenia started to appear in 1980’s, namely, studies with the Wisconsin Card Sorting Test (it tests executive function). These studies proved not only that the executive function is diminished in Schizophrenia but also that it can be enhanced.
Since then, cognitive remediation techniques have been developed to improve several cognitive areas and a variety of programs gave been created.
CRT consists in several nonpharmacological methods focused on improving cognitive processes in people with severe mental disorders. These methods can promote functional improvement, not only by reducing learning limitations, but also by increasing individual confidence.
There are different types of CRT programs: individual or group sessions guided by a therapist, using mainly paper and pen; computerized programs (self-guided or guided by a therapist); and online programs.
The exercises target one or several specific cognitive functions. Sessions consist in repeating series of tasks, beginning at a basic level and gradually increasing difficulty throughout the program, based on principles of errorless learning and targeted reinforcement. The tasks are diverse, using games and neurocognitive tests, for example, memory exercises, motor dexterity tasks, visual reading exercises, etc. Besides the repetition of tasks, it promotes the patient capacity to think about the different ways of solving a task as well as to be aware of its own difficulties.
The vast majority of programs and studies are directed to Schizophrenia. A few examples:
Integrated Psychological Therapy for Schizophrenia (IPT) (Brenner et al, 1992). It is a group program, administered in five modules (cognitive differentiation, social perception, verbal communication, social skills and interpersonal problem solving). The program integrates cognitive and psychosocial interventions;
Cognitive Enhancement Therapy (CET) (Hogarty and Flesher, 1999). This program combines cognitive training by computer with group social cognition training. The objectives are to adequately assess stimuli and social contexts and to enhance thinking flexibility.
Neurocognitive Enhancement Therapy (NET) (Bell et al, 2001). It is a computer-based program, focused in vocational rehabilitation.
Neuropsychological Educational Approach to Rehabilitation (NEAR) (Medalia et al 2002). This treatment was developed within educational psychology and uses training techniques that are intrinsically motivating. Different cognitive skills are trained by individualized computer exercises, within group sessions.
Cognitive Remediation Therapy (CRT) (Wykes and Reeder, 2005). Initially developed in Australia by Ann Delahunty and then reformulated by Til Wykes in the United Kingdom. The main objective is to increase the capacity and efficiency of cognitive functions, trough information processing strategies. It consists of three modules: cognitive shift, memory and planning. The program is applied individually, using mainly paper and pencil tasks.
Cognitive remediation is usually used in combination with pharmacotherapy. Also, if combined with vocational rehabilitation, the effects can be enhanced. For each patient, an interdisciplinary team must define a structured plan. It’s utterly important that the rehabilitation program is adapted to the individual.
During the last decade, CRT has been used mostly for disorders commonly associated with persistent symptoms, cognitive impairment and long-term disability, such as attention deficit disorders, brain injury, and schizophrenia spectrum disorders.
Emerging evidence suggests that CRT is also an effective intervention for mood disorders and that these treatment effects translate into improvements in cognitive performance and possibly functioning.
CRT has recently been developed for children and adolescents with anorexia nervosa. It focuses on decreasing rigid cognitions and behaviours, as well as increasing central coherence.
Younger age, higher education level, shorter length of stay, and lower PANSS Negative and Disorganized factors predict a positive response to cognitive remediation.
CRT, associated with psychopharmacological therapy resulted in significant improvements in global cognition, particularly in terms of verbal memory, executive functioning, and working memory. In the context of psychiatric rehabilitation, resulted in improving vocational and social functioning. Although negative symptoms have not been considered a primary target for CRT, recent research suggested that CRT might also have a positive effect on negative symptoms.
A cognitive remediation program transferring learning skills into the real world is useful to increase the quality of working life in persons with severe mental illness and cognitive dysfunction who want to work competitively. After therapy, increased activations are observed in various brain regions mainly in frontal - especially prefrontal - and also in occipital and anterior cingulate regions during working memory and executive tasks. Several studies provide evidence of an improved functional connectivity after cognitive training, suggesting a neuroplastic effect of therapy through mechanisms of functional reorganization.
Cognitive remediation may be particularly effective in people in the early course of illness or prior to the onset of illness due to the better neuroplasticity in people who are younger and have not yet experienced the consequences of long-term psychosis.
A growing literature using neuroimaging techniques showed that cognitive remediation paradigms engage neural targets.
From a different perspective, some changes in serum levels of Brain derived neurotrophic factor (BDNF) have been described. However, the status of BDNF as a biomarker of cognitive recovery is possibly premature. Some studies suggested a role of genes affecting dopamine modulation on outcomes of cognitive remediation.
Unfortunately, different programs, imaging tasks, and techniques may explain the heterogeneity of observed outcomes. Future studies would need to specify the effect of cognitive training depending on those variables.
Book: Cognitive Remediation Therapy for Schizophrenia: Theory and Practice Professor Til Wykes and Dr. Clare Reeder, Routledge, 2006