ReviewCognitive behavioural interventions for depression in chronic neurological conditions: A systematic review
Introduction
The prevalence rates of chronic neurological conditions (CNCs) vary significantly globally. Crude estimates of the prevalence of Parkinson's disease (PD) across Europe vary between 66.5 and 12,500 per 100,000 [1], whilst the prevalence of dementia is between 640 per 100,000 in the UK for ages between 75 and 84 and 1830 per 100,000 in Finland [2]. The prevalence of epilepsy also varies, with estimates of 330 per 100,000 affected in Italy and as much as 780 per 100,000 in Poland [3]. Whilst the latitude–prevalence relationship is no longer tenable in multiple sclerosis (MS; [4]), the prevalence of this condition also varies greatly across the world, with it being relatively rare in Asia (for example, in Siberia it is estimated to affect 12 to 41 per 100,000) and more common in areas like Europe and the United States of America (in the Shetland Islands, for example, the prevalence is estimated at 152 per 100,000; [5]). The management and treatment of these CNCs significantly increase the cost of care. In the UK, for example, poor mental health exacerbates this cost by up to 45%, equating to approximately £1 in every £8 spent [6].
People living with long term health conditions have an increased prevalence of psychiatric comorbidity [7], which is also true for CNCs. In PD the prevalence of emotional distress is high, with up to 50% of the population affected by depression [7], and up to 28% of patients fulfilling the criteria for a formal anxiety disorder whilst 40% present anxiety symptoms [8]. In MS the probability of a comorbid depression is also high, with a lifetime prevalence of 50% [9]. Dementia is also associated with a high prevalence of both anxiety and depression, with research suggesting that 72% of vascular dementia (VD) and 38% of Alzheimer's disease (AD) patients suffer two or more anxiety symptoms and 19% (VD) and 8% (AD) suffering depression [10]. An estimated 20–30% of epilepsy patients are affected by a psychiatric comorbidity and even more in patients with refractory seizures [11]. A study of 60 patients with refractory epilepsy revealed that approximately 70% had a comorbid DSM III disorder [12]. The consequences of comorbid psychiatric conditions in CNCs are widespread and severe. For example, depression and anxiety in PD are associated with faster disease progression [13], leaving the workforce [14], lower health-related quality of life [15], higher levels of dependency, and greater caregiver burden [16].
The National Institute for Clinical Excellence (NICE) guidelines for the management and treatment of depression in chronic physical health problems present a stepped-care model that consists of increasingly intensive levels of CBT interventions before suggesting SSRIs for treatment refractory depression (including sub threshold depression; [17]). Guidelines acknowledge that there is only a limited evidence-base for using specific anti-depressant medication in such conditions and highlight the risk of interaction between psychotropic and non-psychoactive medication. The psychological interventions recommended by the NICE guidelines range from education and advice on sleep hygiene, to behavioural activation and thought challenging. However, the application of more high-intensity interventions may be limited by the impairment characteristics of neurological conditions. However a more recent systematic review and meta-analysis found some evidence for efficacy of antidepressants improving mood in people with neurological conditions but little to suggest that such treatments improve quality of life, day-to-day functioning, and cognitive outcomes [18].
Systematic reviews exist that evaluate the efficacy of either CBT or antidepressants in specific neurological conditions [19], [20], [21] and antidepressants in neurological conditions as a category [18]. However no such reviews could be identified assessing CBT in neurological conditions as a category. This is relevant as many neurological conditions share impairment characteristics such as in executive dysfunction and mobility limitations that may limit the application of traditional CBT interventions and so the results of this review may be generalizable. The objective of this review is to assess the clinical effectiveness of CBT for depression comorbid to chronic neurological conditions, investigating whether the hypothesized limitations of the application of traditional CBT interventions in chronic neurological conditions has a detrimental effect on treatment outcomes. In this review, we have excluded acquired brain injury (such as stroke) studies from this review because we have chosen to focus on neurological conditions that are progressive and without a potential recovery course; we believe that these shared characteristics will have implications for cognitive specificity [22] and the characteristic of the CBT treatment protocols utilised by the studies reviewed in this paper. We focus on comorbid depression rather than anxiety in this review not only for reasons again that relate to cognitive specificity and treatment protocols, but also for pragmatic reasons such as maintaining a focus for this review.
Section snippets
Methods
This systematic review was conducted at the Institute of Psychiatry, Psychology, and Neuroscience (King's College London) using studies that were retrieved by performing electronic searches of the Cochrane Controlled Trials Register, OVID MEDLINE, PubMed, and PsychINFO, along with the reference of identified papers. The entire timescale was used up to December 2014 (week 50) inclusive.
The search strategy employed the following MESH terms: “Parkinson's disease” or “dementia” or “Alzheimer's
Results
164 papers retrieved through the search strategy and reference lists of papers were identified. Of these, nine were duplicates and 123 were excluded on title and/or abstract review because they did not fulfil the inclusion criteria. The remaining 32 texts were read in full and 10 were excluded when assessed again against eligibility criteria (three because the studies were not reporting a cognitive or behavioural intervention and three because they were not evaluating treatment) and four
Discussion
This systematic review aimed to evaluate the efficacy of CBT and CBT-based interventions for the treatment of depression that is comorbid to CNCs. Overall the reviewed studies suggest that cognitive and/or behavioural interventions can be an effective treatment for depression in these conditions. However several issues were highlighted by this review concerning the use of controls and non-specific effects of therapy, treatment-delivery modality and dropout rates, paucity of blinding, and
Acknowledgements
Authors BAF and RGB receive salary support from the National Institute for Health Research (NIHR) Mental Health Biomedical Research Centre and Dementia Research Unit at South London and Maudsley NHS Foundation Trust and King's College London. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health.
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2021, General Hospital PsychiatryCitation Excerpt :In relation to medical management, one meta-analysis found evidence that antidepressants can improve depression outcomes and are safe in patients with PD, MS, ABI and epilepsy, but there was insufficient evidence anti-depressants can improve functional or cognitive outcomes [45]. On the other hand, there is some evidence that psychological interventions based on cognitive behaviour therapy (CBT) can improve depression and disability outcomes in adults with both acquired and chronic neurological disorders [46,47] and emerging research that psychological interventions based on compensatory cognitive rehabilitation, which provide strategies for maximising cognitive function and minimising the impact of cognitive difficulties on day-to-day functioning, can improve perceived cognitive outcomes (e.g., memory complaints) [48–50]. However, further research in this area is needed and more rigorous clinical trials are required before firm conclusions can be made about the most effective ways of managing psychological and neuropsychiatric outcomes in people with neurological disorders [51–53].
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2020, Journal of Psychosomatic ResearchCitation Excerpt :This is encouraging given people with neurological disorders often report significant difficulties in these areas, which can be further complicated by the neurological disease and treatment regimens [6,19]. The magnitude of clinical improvements in depression and anxiety symptoms observed in this trial compare favourably to reviews of psychological interventions, based on CBT principles, for patients with both chronic [16] and acquired neurological disorders [17]. However, it should be noted that there are currently few benchmarks of outcomes of psychological interventions relevant across patients with different neurological disorders.