Cognitive Enhancers in Schizophrenia: non-pharmacological approach

This post is a follow up part to the previous post, which introduced the pharmacological approach to the enhancement of cognition in schizophrenia.

With no major clinical success to date in targeting cognitive deficits in schizophrenia, attention shifted to behavioural, neuro-cognitive interventions. These approaches are based on the assumption that a broad and intensive activation of neural processing systems can stimulate neural resources to improve their functioning. It is believed that intense activation of cognitive (mental) systems damaged in patients with schizophrenia could effectively lead to a general and lasting functional improvement. As a result, several cognitive training strategies have been developed and these can generally be divided into either (1) COGNITION-ENHANCING or (2) COMPENSATORY approaches. The former approaches train patients with laboratory tasks designed to improve specific abilities in various cognitive domains, such as perception, learning, or memory. On the contrary, the latter approaches attempt to bypass cognitive deficits and teach strategies to compensate for them by relying on aids or other processes (Tomás, Roder, & Ruis, 2010).

1) COGNITION-ENHANCING PROGRAMMES

• Cognitive Remediation Therapy (CRT)
• Cognitive Enhancement Therapy (CET)
• Integrated Psychological Therapy for Schizophrenia (IPT) 

CRT aims to improve attention, working memory, cognitive flexibility, planning and executive functioning. CRT is usually administered via use of a computer, with the tasks appearing on the monitor. Research to date demonstrates small to moderate durable effects of CRT and that irrespective of therapy characteristics CRT can provide benefits to patients with cognitive difficulties. Although having more symptoms is associated with smaller effects, all participants were shown to benefit from CRT.

CET is a recovery-phase intervention for symptomatically stable schizophrenic out-patients with reduced relapse risk (Hogarty et al., 2004). This programme tackles areas and disabilities of a wider functional range. For example, specifically designed exercises target analytic logic, decision making, strategic and foresightful planning, as well as the intuitive thinking that supports social cognition (thinking). CET is a small-group approach that combines approximately 75 hours of progressive software training exercises in attention, memory and problem solving with 1.5 hours per week of social cognitive group exercises. Consistent positive results are fund in processing speed and verbal memory. A drawback of this approach is that it is only applicable to patients with a certain intellectual level (with an IQ above 80) who are psychopathologically stable (Tomás et al., 2010).

IPT integrates neuro-cognitive and psychosocial rehabilitation methods.IPT is administered to groups and consists of five, hierarchically organised sub-programs: cognitive differentiation, social perception, verbal communication, social skills and interpersonal problem solving. Studies typically reveal the largest improvements in neuro-cognitive functioning, however, effects on psychosocial functioning tend to be smaller (Roder et al., 2006). More research is currently needed to evaluate the effectiveness of this approach.

2) COMPENSATORY REHABILITATION PROGRAMMES

• Errorless Learning (EL)
• Cognitive Adaptation Training (CAT)

EL involves two main procedures: prevention of errors during the learning phase and automation of perfect task execution (Terrace, 1963). It refers to teaching procedures that are designed in such a way that a learner/patient does not have to - and does not- makes mistakes as she/he learns new information and new procedures.

CAT uses environmental supports and various clues such as signs, check-lists or alarmed drug packaging. It also encourages organisation of belongings and the sequencing of appropriate routines.

In effect, compensatory strategies work to some extent, however, they do not succeed in achieving pre-morbid levels of performance (Tomás et al., 2010). Moreover, they are aimed at people with significant cognitive impairment that is difficult to restore and thus renders them less suitable for people with recent illness who are more intact.

References

Roder, V., Mueller, D. R., Mueser, K. T., & Brenner, H. D. (2006). Integrated psychological therapy for schizophrenia: is it effective? Schizophrenia bulletin, 32 Suppl 1, S81-93. doi:10.1093/schbul/sbl021 

Terrace, H. S. (1963). Discrimination learning with and without errors. Journal of the Experimental analysis of Behaviour, 6, 1-27.

Tomás, P., Roder, I. F. V., & Ruiz, J. C. (2010). cognitive Rehabilitation Programs in Schizophrenia: Current Status and Perspectives. International Journal of Psychology and Psychological Therapy, 10(2), 191-204.

Enhancing Cognition in Schizophrenia - pharmacological approach

Cognitive impairment is a core feature of schizophrenia, with more than 80% of patients showing significant impairments (Keefe & Fenton, 2007). The range of cognitive impairments in individuals with schizophrenia is broad, with the more robust and replicable deficits typically found in the domains of processing speed, episodic memory, working memory and executive function. These impairments have been shown to be associated with various impaired functional outcomes and thus development of new therapies to enhance cognition has become one of the most pressing challenges. Cognitive deficits persits throughout the course of the illness and as such, negatively affect daily functioning, work outcomes and treatment adherence. While anti-pscyhotic medications can control psychotic symptoms for the majority of patients, such improvements do not automatically transfer into the functional outcome, such as community functioning. Additionally, anti-psychotic drugs that are currently the main form of treatment in schizophrenia demonstrate only a modest positive effect on cognition.

Despite a large number of compelling rationales and significant body of preclinical data, there are no dramatic or consistent results that any one medication has the power to increase cognitive skills to the level of normal functioning. While a wide range of cholinergic, dopaminergic, glutamatergic and cannabinoid compounds have been developed, the Food and Drug Administration (FDA) has not yet approved any of the drug development programmes specifically aimed at treating cognitive impairments in schizophrenia.

Pharmacological approach: Potential Cognitive-Enhancing Drugs in Schizophrenia

1. Antipsychotic Drugs (APDs)

While numerous studies have demonstrated the dramatic efficacy of APDs in suppressing psychotic symptoms and preventing their recurrence, they have also revealed their inability to alleviate the negative and cognitive symptoms of the illness. There are, however, some studies that suggest that some of the newer atypical antipsychotics e.g. aripiprazole, clozapine, quetiapine, olanzapine, risperidone and ziprasidone, may provide minimal benefits in certain specific areas of cognition.

2. Donepezil, Rivastigmine, Galantamine

Researchers sometimes focus on drugs that have proved effective in other cognitively impaired conditions, such as in dementia. Several drugs approved for dementia stimulate acetylcholine by blocking its breakdown, which has been shown to improve cognition and slow cognitive decline. Donepezil belongs to this type. The results in schizophrenia field, however, are not very encouraging, with only a few studies showing somewhat minimal memory improvement.

Rivastagime has also been investigated but only in smaller-scale studies. No significant findings have been reported to date.

Evidence of cognitive benefit with galantamine has been mixed so far. The overall trend indicates that at lower doses galantamine exerts a positive effect on cognition but at higher doses it is consistently associated with negative results. The most effective dosage is yet to be established.

3. Nicotine and nicotinic receptors

It is now widely accepted that nicotinic receptor abnormalities are present in schizophrenia. The vast majority of studies found some positive effects, improvements were frequently recorded in working memory and attentional/executive control functions and in episodic memory. However, nicotine did not improve every measure examined in each study and the magnitude of the effects was not large. Additionally, nicotine as a therapeutic agent may be limited by tachyphylaxis.

4. Modafinil

Modafinil is a wakefulness-promoting agent, shown to be effective in enhancing cognition in sleep-deprived and healthy individuals, as well as in some psychiatric disorders. While having effect on many neurotransmitter systems, modafinil has an uncertain mechanism of action. Results at this stage appears to be inconclusive. Benefits demonstrated by early studies were not replicated by larger-scale studies.

NB: Non-pharmacological applications will be reviewed in a future post

Reference

Keefe, R. S. E., & Fenton, W. S. (2007). How should DSM-V criteria for schizophrenia include cognitive  impairment? Schizophrenia bulletin, 33(4), 912-20. doi:10.1093/schbul/sbm046

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Problem solving for personality disorder

Mary McMurran and Stephen Coupe describe a promising approach to a distressing disorder

 

What is problem-solving therapy?

Problem-solving therapy has a solid evidence base for alleviating distress and improving social functioning in people with a range of psychological and health problems. This approach has considerable appeal for both therapists and clients, in that its basic principles are easy to understand, it does not pathologise individuals, and it empowers people to solve those problems that they prioritise. Applications of problem-solving therapy for people who are diagnosable with personality disorders have been pioneered by researchers and clinicians in the UK.

Social problem solving is the process by which individuals attempt to discover and apply adaptive means of coping with the wide variety of stressful problems encountered in the course of everyday living (D’Zurilla & Nezu, 2007). There is abundant evidence of an association between social problem-solving deficits and psychological distress, physical ill health, substance misuse, hostility and aggression, and mental health problems. Problem-solving therapy can help people to cope better with everyday problems and can lead to better mental and physical health. Problem-solving therapy teaches the skills required for effective social problem solving. These are the ability to recognise problems when they arise, define the problem clearly and accurately, set realistic goals for change, produce a diversity of possible solutions, anticipate outcomes, devise effective actions plans that have stepwise stages, and carry out those action plans to solve problems effectively. 

Click on the following link to read more about: Problem Solving Therapy