Cognitive remediation: The foundation of psychosocial treatment of schizophrenia

Despite advances in psychopharmacology, schizophrenia remains a severely disabling illness. It is now appreciated that cognitive impairment mediates the functional disability associated with the disorder. Cognitive remediation, which is defined as ‘a behavioural training based intervention that aims to improve cognitive processes (attention, memory, executive functioning, social cognition or meta cognition) with the goal of durability and generalization’ is a therapeutic approach that improves cognition and when combined with other rehabilitation strategies improves real-world functioning (Wykes et al., 2011).

Cognitive deficits and schizophrenia

Neurocognitive deficits are common in schizophrenia, albeit there is considerable heterogeneity in the nature and severity of these cognitive deficits between individuals with schizophrenia. The cognitive deficits are so common that they have been proposed as a criterion for the diagnosis of schizophrenia in the DSM V diagnostic system (Keefe and Fenton, 2007). Cognitive difficulties are frequently seen as a separate domain of psychopathology in schizophrenia in factor analyses of symptom profiles using such instruments as the Positive and Negative Syndrome Scale.

The natural history of cognitive impairment in psychosis is now better understood. Birth cohort studies have demonstrated that children who later develop schizophrenia show a range of subtle changes in various cognitive and educational domains long before they present with the disorder (Welham et al., 2009). Further cognitive decline occurs prior to the onset of psychosis but appears relatively stable after the onset of psychosis. There are dynamic cognitive changes occurring with the transition to psychosis, with deficits in visual memory and attention set shifting (Wood et al., 2007). Curiously, from a lifespan perspective, cognitive impairment may be one of the most stable features of schizophrenia. In addition there are problems in cognitive processing, with impaired strategy use, reduced automatic processing and reduced cognitive processing capacity. When considering cognitive impairment of psychosis more broadly, social cognitive deficits are a separate but related domain of pathology with impaired facial recognition, social perception, theory of mind, attribution bias and emotional processing.

Cognitive remediation (CRT) and schizophrenia

There is now clear evidence from a number of meta-analytic studies that cognitive remediation is effective in remediating the cognitive deficits of psychosis (McGurk et al., 2007; Wykes et al., 2011). Fourteen different programmes have been used with the common therapeutic factors being the predominant use of strategy-based learning and coupling CRT with psychosocial rehabilitation. The meta-analysis by Wykes et al. (2011) included 40 studies, a total of 2104 participants, from 11 countries with an effect size of 0.43 for global cognition. In general CRT is most effective following stabilization of acute symptoms. Recommended treatments are at least an hour long, with two to four sessions per week. The average length of treatment in the latest meta-analysis was 32.2 hours (Wykes et al., 2011).

There are multiple CRT programmes available. Programmes designed specifically for schizophrenia take into account the insidious nature of cognitive impairment with associated problems in motivation and perceived self-efficacy. These primary and secondary consequences of the illness have informed the approach developed by Professor Alice Medalia (i.e. Neuropsychological Educational Approach to Remediation; NEAR) (Medalia et al., 2001). Past experiences of failure in learning situations can contribute to a reluctance to engage in therapies related to cognition. In this approach attention is paid to the learning environment and activities that are intrinsically motivating. An important consumer-led acceptability study showed that CRT is valued and acceptable to participants (Rose et al., 2008). This study also drew attention to a possible side effect of CRT with self-esteem improving in those participants whose memory improved but declined in those not benefitting from the programme.

Given the natural history of cognitive deficits of psychosis, predating diagnosis, the ‘at risk’ time may be when the therapy will be most potent and relevant (Eack et al., 2010). Research in CRT in early psychosis has encouraged trials of CRT in at-risk mental states (Rauchensteiner et al., 2011).

Early studies focused on improvement in neurocognition but more recent studies also emphasize functional improvement associated with CRT. The best evidence to date comes from research into CRT integrated with vocational rehabilitation (VR) with the coupling of CRT with VR resulting in more hours worked and improved job retention (McGurk and Wykes, 2008; McGurk et al., 2007, 2009). Furthermore, the relationship between neurocognition, social cognition and functional outcome (Nuechterlein et al., 2011; Schmidt et al., 2011) suggests that improved neurocognition may be a necessary basis for other recovery strategies. Research that has paired cognitive remediation with social skills training (Bowie et al., 2012) has found that these combined approaches are more powerful than the other psychosocial treatment alone. Rehabilitative programmes such as Integrated Psychosocial Therapy (Roder et al., 2011) or Cognitive Enhancement Therapy (Hogarty et al., 2004) that combine cognitive remediation, social cognition therapy and other elements of psychosocial rehabilitation, significantly improve outcome for people with schizophrenia (Roder et al., 2010). However, further effectiveness research needs to be conducted on how best to combine treatments, in what sequence or combination.

The Australian context

The second national mental health survey found that despite an increase in psychosocial rehabilitation from the previous survey (22.9% in 1997/98 to 36.8% in 2010), only a minority of people with a psychotic illness were able to access treatment specifically targeted at community recovery (Morgan et al., 2012). This contrasts with the very high penetration of pharmacotherapy, with 94.4% of people with psychosis from the same survey taking medication at some stage over the previous 12 months. Functional impairment continues to characterize the lived experience of people with psychosis. As cognitive deficits are central to that impairment, the broad use of cognitive remediation in tandem with other psychosocial interventions should be basic to improving rehabilitation outcomes. Programmes remediating the neurocognitive and social cognitive deficits of psychosis need to become ‘institutionalized’ into routine care before an estimate can be made of ‘treatment resistant’ functional impairment.

Australia has experience in the provision of CRT programmes. Queensland clinicians have developed a programme that provides CRT in combination with other psychosocial programmes. Redoblado-Hodge and colleagues published a randomized controlled, multisite study of CRT in the ‘naturalistic and ecological-valid setting’ of inpatient and community public mental health services in Sydney (Redoblado-Hodge et al., 2010). The improved cognitive performance was sustained at 4 months and generalized to improved social and occupational functioning. This study supported the concept of implementation and dissemination of CRT in a range of Australian mental health services. Incorporating a recommendation for CRT in schizophrenia treatment guidelines would also assist the ‘institutional’ integration of this therapeutic modality.

Summary

Cognitive deficits are common and central to the disabling consequences of schizophrenia. Comprehensive treatment of psychosis should include cognitive remediation as current antipsychotics are not effective on this domain of the illness. Cognitive remediation has been shown to be an effective intervention leading to improved cognition and real world functioning, especially when combined with other psychosocial treatments. Cognitive remediation could provide a foundation upon which other effective treatments can be built. CRT has been successfully introduced into a variety of Australian mental health services. The clinical challenge is to implement and disseminate CRT so that it becomes ‘treatment as usual’ for people living with schizophrenia.