Description of the condition
Chronic obstructive pulmonary disease (COPD) consists primarily of chronic bronchitis and emphysema, conditions which are characterised by the inflammation of airways and the destruction of pulmonary tissues. The diagnosis of COPD is based on the documentation of a post bronchodilator forced expiratory volume1/forced vital capacity (FEV1/FVC) less than 70% (Rabe 2007). Anxiety disorder is a generalised term for a myriad of abnormal and pathological fear and anxiety states, including generalised anxiety disorder (GAD), panic disorder (PD), agoraphobia, neurocirculatory asthenia, obsessive-compulsive disorder (OCD), and phobic disorders.
Evidence suggests that there is an increased prevalence of anxiety disorders in patients with COPD (Maurer 2008). The lifetime prevalence of GAD in particular amongst patients with COPD is estimated at between 10% and 15.8% (Brenes 2003). GAD is defined as excessive anxiety which lasts for at least six months. Individuals must also experience three or more of the following symptoms: difficulty in concentrating; fatigue after little exertion; sleep disturbance; a sensation of being 'keyed up' (nervous or anxious); irritability or muscle tension, or both (Diagnostic and Statistical Manual (DSM) IV criteria) (APA 1994). Rates of anxiety symptoms in patients with COPD range from 13% to 51% and are higher than the rates in patients with heart failure, cancer, and other medical conditions (Brenes 2003).COPD is associated with a higher risk of anxiety, and once anxiety develops among patients with COPD it is related to poor health outcomes, including in terms of exercise tolerance, quality of life and COPD exacerbations (Eisner 2010). By compromising health status, mood disorders lead to increased risk of hospitalisation and re-hospitalisation (Gudmundsson 2005) and hence also increase direct and indirect costs to the health system.
Various models could be considered to explain increased levels of anxiety and panic in patients with COPD (Ley 1985; Perna 2004). One of the models (Clark 1986) explains this relationship as catastrophic misinterpretations of ambiguous bodily sensations (such as shortness of breath, rapid heart rate) which increase arousal, creating a positive feedback loop that results in a panic attack. A crucial difference between physically healthy people and those with COPD is that in the latter, breathing, the most basic of all physical functions necessary for life, is objectively threatened (as measured by tests of lung function) and subjectively difficult. Dyspnoea (shortness of breath) can be an unpleasant and potentially frightening experience at any time, and, as the key symptom of an eventually fatal illness like COPD, it is an ambiguous sensation open to catastrophic interpretation, leading to increased levels of anxiety and panic in people with COPD (Livermore 2010).
Description of the intervention
Management strategies for the treatment of anxiety disorders in people with COPD include both pharmacological and non-pharmacological interventions. Evidence that pharmacological therapies (anti-anxiety and/or antidepressant medications) provide statistically or clinically significant benefits for this group of patients is limited (Usmani 2011). Psychological therapies include cognitive and/or behavioural therapies, psychodynamic psychotherapy, interpersonal psychotherapy, non-directive therapy, support therapy and counselling (Rose 2002; Davison 2003). Psychological therapies are intentional interpersonal relationships used by trained psychotherapists to aid patients with problems of living, with an aim of increasing the individual's well-being. Psychological therapies may also be performed by practitioners with a number of different qualifications, including psychologists, marriage and family therapists, occupational therapists, licensed clinical social workers, counsellors, psychiatric nurses, psychoanalysts, and psychiatrists.The mode of delivery for these therapies comprise individual, group or family (including couple) therapy, performed by a healthcare professional.
How the intervention might work
Because COPD is an irreversible condition, treatment recommendations are aimed at improving quality of life (Norweg 2005). Current evidence examining quality of life suggests a reduction in satisfaction above and beyond what should be expected by COPD disease severity or co-morbid medical illnesses (Coventry 2007), indicating that psychological status plays an intrinsic role in overall well-being. A recent study examining the impact of anxiety on the lives of patients with COPD found that patients felt isolated and would avoid social occasions and usual daily activities (Willgoss 2011). As a result, therapies targeting the reduction of psychological stressors should be expected to improve quality of life (Ries 1995; Rose 2002; Baraniak 2011).
Psychological therapies are often based on the assumption that psychological outcomes such as anxiety are linked with physical manifestations of COPD, for example dyspnoea, which can precipitate episodes of anxiety (Wu 2004). It has been hypothesised that a patient's fear and misinterpretation of bodily experiences from dyspnoea and hyperventilation cause a panic reaction (Nutt 1999). Alternatively, underlying psychological distress can contribute to an increased risk of symptom exacerbations, particularly those treated in the patient's own environment (Laurin 2011). As such, patients with anxiety and panic disorders interpret threats as more dangerous due to a higher awareness of cues such as dyspnoea and tachycardia (Mikkelsen 2004).
A psychological therapy, cognitive-behaviour therapy (CBT), aims to identify and correct dysfunctional emotions, behaviours and cognitions through a goal-oriented, systematic procedure (Rose 2002; Kaplan 2009). In the case of COPD patients, CBT may be a means of managing concurrent anxiety and depression. While not in itself improving an individual's medical condition, CBT may serve to increase perceived self-efficacy and motivate patients to manage their physical condition, thereby improving quality of life (Kunik 2001). Moreover, the learning about oneself that occurs in various forms of psychological therapy may in itself influence the structure and function of brain (Kandel 1998) or may have a significant impact on serotonin metabolism (Viinamaki 1998). 'Third wave CBT' applies to behavioural psychological therapies that integrate mindfulness and acceptance of unwanted thoughts and feelings with a behavioural understanding of emotional suffering, to elicit change in thinking process. Behavioural therapy includes methods that focus on behaviours, not the thoughts and feelings that might be causing them. The behavioural approach to therapy assumes that behaviour that is associated with psychological problems develops through the same processes of learning that affect the development of other behaviours. Psychodynamic therapy focuses on unconscious processes as they are manifested in patients' present behaviour. Hence by making the unconscious aspects of their life a part of their present experience, psychodynamic therapy helps people understand how their behaviour and mood are affected by unconscious feelings. Humanistic psychotherapy emphasises human uniqueness, positive qualities, and individual potential. It works by emphasising one's capacity to make informed and rational choices and develop to one's maximum potential. Integrative therapies are approaches that combine components of different psychological therapy models.
Why it is important to do this review
Anxiety disorders in people with COPD have been shown to increase disability and impair functional status, resulting in an overall reduction in their quality of life (Beck 1988; Weaver 1997). Importantly, the impact of anxiety on these outcomes was shown after adjusting for other potential confounders such as general health status, other medical conditions and COPD severity (Brenes 2003). Kim 2000 reported that anxiety and depression were more strongly related to functional status than the severity of COPD. Co-morbid anxiety in an elderly population with COPD has been suggested as a significant predictor of the frequency of hospital admissions (Yohannes 2000). A recent study has shown that among patients with COPD, anxiety is related to poorer health outcomes including worse submaximal exercise performance, greater risk of self-reported functional limitations and a higher longitudinal risk of COPD exacerbations (Eisner 2010). However, the evidence for treatment of anxiety disorders in COPD is limited, and there are limited data to support the efficacy of medication-only treatments (Borson 1998). The results of a Cochrane review evaluating the effects of pharmacological interventions for anxiety in patients with COPD are inconclusive (Usmani 2011). A feasibility study of antidepressants in this population suggested poor acceptance of antidepressants for various reasons including side-effects and reluctance to take ‘yet another medication’ (Yohannes 2001). Furthermore the association between anxiety/panic and dyspnoea/COPD had been explained by various psychological theories (Clark 1986; Livermore 2010). It is important therefore, to evaluate psychological therapies for the alleviation of these symptoms in patients with COPD.
In light of the health burden caused by psychological disorders and the limited evidence supporting treatment options, this review is one of four linked Cochrane reviews that will assess the effects of pharmacological and psychological therapies for the treatment of anxiety and depression in patients with COPD, one of which has already been published (Usmani 2011) and two of which are in progress (Usmani 2013a, Usmani 2013b).