{'fraction_non_alphanumeric': 0.03548053737512918, 'fraction_numerical': 0.010678608336203927, 'mean_word_length': 5.439024390243903, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Depression and anxiety in elderly patients with chronic obstructive pulmonary disease.

Chronic obstructive pulmonary disease (COPD) is a major cause of morbidity, disability and mortality in old age [1]. It has been predicted that COPD will be the world’s fifthranking cause of disability by 2020 [2]. Co-morbid psychological impairments (depression and anxiety) are common in COPD and are often associated with increased disability and morbidity. They also impair quality of life in COPD and are often not fully explored in the clinical management of COPD patients. In the UK, the National Institute of Clinical Excellence COPD Guidelines [1] estimates the prevalence of depression in COPD to be 40% (36–44%) and suggests that anxiety symptoms may have a prevalence of 36% (31–41%) [3]. With such a high prevalence, why is depression so often undetected and untreated? First, recognition of co-morbid depression is difficult, because some of the physical symptoms of COPD may mimic the core symptoms of depression, for example, poor sleeping pattern, anorexia and loss of enjoyment due to breathlessness. Second, screening tools for depression and anxiety symptoms are not routinely employed by health care professionals caring for COPD patients. Third, patients often deny that they are suffering from anxiety and depression, perhaps because of perceptions of the stigma attached to these problems [4]. Unrecognised and untreated depression has major implications in compliance with medical treatment and may increase the frequency of consultation with health services, for example, in primary care [5]. In COPD, it increases the likelihood of hospital admission in those most severely disabled [4]. Anxiety is common in patients with COPD. It is often associated with clinical depression, and a study from our centre identified that 37% of depressed COPD patients had clinical anxiety compared with 5% of non-depressed COPD patients [4]. COPD is among a number of medical disorders associated with a high rate of depression. The wide range of conditions suggest that the aetiology is multifactorial. Suggested mechanisms include cerebrovascular and microangiopathy (heart disease, diabetes), localised disruption to frontostriatal brain circuits (stroke), social adversity (diabetes) and neurodegenerative brain disease (Alzheimer’s disease, idiopathic Parkinson’s disease), pain (arthritis, cancer) and oncological therapy (cancer) [6]. Furthermore, there is robust evidence that depression worsens the outcome and mortality of many of these conditions [6], and this has been demonstrated for COPD too [7]. There is little data regarding aetiological mechanisms leading to depression in COPD. However, disability and handicap are powerful predictors of depression and are likely to be the major determinants in COPD [8]. Whether biological mechanisms play a significant role has not been clarified.