Delirium, dementia, and other cognitive disorders

Organic psychiatric disorders result from brain dys­function caused by organic pathology inside or outside the brain. Dementia is the most common condition, with Alzheimer’s disease alone affecting 1 per cent of the population at 60 years, rising to 40 per cent over 80 years. Many of the rarer organic psychiatric dis­orders tend to affect a wider age range, but present in similar ways. Given the changing demographics of most developed countries, disorders producing cognitive im­pairment in older adults are becoming increasingly important for provision of healthcare services and in daily clinical practice. This chapter will cover the more common causes of cognitive impairment, and there is additional information in Chapters 18 and 20 on psych­iatry of older adults in psychiatry and medicine. There are three common clinical presentations of or­ganic psychiatric disorders: … 1 Delirium— an acute generalized impairment of brain function, in which the most important feature is impairment of consciousness. The disturbance of brain function is generalized, and the primary cause is often outside the brain; for example, sepsis due to a urinary tract infection. 2 Dementia— chronic generalized impairment, in which the main clinical feature is global intellectual impairment. There are also changes in mood and behaviour. The brain dysfunction is generalized, and the primary cause is within the brain; for example, a degenerative condition such as Alzheimer’s disease. 3 Specific syndromes— which include disorders with a predominant impairment of isolated areas; for example, memory (amnesic syndrome), thought, mood, or personality change. These include neurological disorders that frequently result in organic psychological complications; for example, epilepsy…. Table 26.1 lists the main categories of psychiatric disorder associated with organic brain disease. The following sections describe these syndromes and the psychiatric consequences of a number of neurological conditions. Organic causes of other core psychiatric conditions (e.g. anxiety and psychosis) are covered in the relevant specific chapters. Delirium is characterized by an acute impairment of consciousness producing a generalized cognitive impairment. The word delirium is derived from the Latin, ‘lira’, which means to wander from the furrow. Delirium is a common condition, affecting up to 30 per cent of patients in general medical or surgical wards, with the primary cause often being a sys­temic illness. The term ‘acute confusional state’ is a synonym for delirium.

The scale of the problem

One in four individuals suffer from a psychiatric disorder at some point in their life, with 15– 20 per cent fitting cri­teria for a mental disorder at any given time. The latter corresponds to around 450 million people worldwide, placing mental disorders as one of the leading causes of global morbidity. Mental health problems represent five of the ten leading causes of disability worldwide. The World Health Organization (WHO) reported in mid 2016 that ‘the global cost of mental illness is £651 billion per year’, stating that the equivalent of 50 million working years was being lost annually due to mental disorders. The financial global impact is clearly vast, but on a smaller scale, the social and psychological impacts of having a mental dis­order on yourself or your family are greater still. It is often difficult for the general public and clin­icians outside psychiatry to think of mental health dis­orders as ‘diseases’ because it is harder to pinpoint a specific pathological cause for them. When confronted with this view, it is helpful to consider that most of medicine was actually founded on this basis. For ex­ample, although medicine has been a profession for the past 2500 years, it was only in the late 1980s that Helicobacter pylori was linked to gastric/ duodenal ul­cers and gastric carcinoma, or more recently still that the BRCA genes were found to be a cause of breast cancer. Still much of clinical medicine treats a patient’s symptoms rather than objective abnormalities. The WHO has given the following definition of mental health:… Mental health is defined as a state of well- being in which every individual realizes his or her own po­tential, can cope with the normal stresses of life, can work productively and fruitfully, and is able to make a contribution to her or his community.… This is a helpful definition, because it clearly defines a mental disorder as a condition that disrupts this state in any way, and sets clear goals of treatment for the clinician. It identifies the fact that a disruption of an individual’s mental health impacts negatively not only upon their enjoyment and ability to cope with life, but also upon that of the wider community.

Psychiatry and you

Improving your emotional resilience is a key task for you as a medical student. As a future doctor, your health and well- being are vital to that of your patients: if you are not functioning reliably, you will not be able to help your pa­tients as much as you otherwise would. It is therefore vital that you look after your body and mind and, by implica­tion, adopt a lifestyle that is both healthy and sustainable. It is often said that doctors make bad patients. There is some evidence that doctors are slow to seek help for health problems, and comply poorly with advice given by other healthcare professionals. In addition, doctors’ lives may be unhealthy, with high levels of stress, low levels of exercise, and excessive consumption of alcohol. The mental health of doctors is a particular con­cern. Doctors are at relatively high risk of mental dis­order, and female doctors appear to be at higher risk of suicide than women in the general population. The reasons are several, and include the following: … ● The nature of doctors. Doctors are driven to succeed, and do not tolerate failure well. It is inevitable that some of our patients will die, some treatments will not be successful, and that, in a professional lifetime, some mistakes will be made. Our aim should be to reflect on and learn from these events, and then to move on positively. ● The nature of doctors’ work. Doctors tend to work hard, work for long hours, and work in challenging, resource- constrained environments. ● Poor help- seeking. Doctors may be reluctant to seek help for their medical problems, and this is particularly likely when the problem is psychiatric. ● Unsupportive and unsustainable lifestyle. Many doctors have challenging careers and challenging home lives, and allow themselves little time to recharge their batteries away from these ever-present stressors. They may not prioritize the maintenance of important resilience factors, such as the relationship with their partner, or interests outside medicine. ● Knowledge of and access to the means of suicide. Doctors (and vets, farmers, and pharmacists, to whom the above- mentioned factors also apply) have special expertise in the use of chemicals which are toxic in overdose.

Personality and its disorders

Personality is a difficult concept to define: it is ex­tremely hard to encapsulate what makes a person ‘who they are’ in general terms. Personality is typically thought of as the set of characteristics which make us think, feel, and act in our own unique way. Personality is pervasive; people tend to behave in similar ways throughout life and across differing social and inter­personal contexts. The characteristics of personality, called traits, are a set of common features which are observed in variable degrees in different people. Traits provide a useful structure in which to describe a per­sonality: Box 31.1 shows some common personality traits. Some traits may be perceived as an asset to the individual, while others are more of a nuisance. We all have a little more or a little less of any given trait. The word ‘temperament’ rather than personality is used to describe the behavioural characteristics dis­played by young children. This is because our person­ality takes time to develop; it is shaped by a multitude of environmental, biological, and factors which interact throughout early life. By our late teens or early twenties, the majority of individuals have the set of traits which define the personality we will have for the rest of our lives. Having an understanding of an individual’s per­sonality helps clinicians to predict their patients’ re­sponse to illness and its treatment. The majority of us have some less favourable aspects to our personality, but we work around them and/ or have more prominent favourable traits that allow us to get on with our lives. For a minority of people, their less favourable traits are so prominent that they cause problems for themselves or for those around them. It is these people who we think of as having a personality disorder. It is extremely difficult to draw a line between normal personality and personality disorder, so this simple pragmatic approach is helpful in clinical practice. People with a personality disorder may: … ● have difficulties with social situations and relationships; ● have difficulties controlling their feelings and/ or behaviour; ● react in unusual ways to illness or to treatment; ● behave in unusual ways when mentally ill; ● have more extreme or unusual reactions to stressful events; ● behave in ways that are detrimental to themselves or others ● be more prone to developing other types of mental disorder.

Problems due to use of alcohol and other psychoactive substances

Archaeological evidence has demonstrated that for at least the past 10,000 years humans have been using psychoactive substances. From the chewing of coca leaves in Ancient Peru (c.4000– 3000 bce) to the popular use of laudanum in Victorian England, the recreational, cultural, and medicinal use of ‘mind- altering’ substances has been widespread. As of 2016, alcohol and other psychoactive substances remain a leading cause of medical and social problems world­wide: humans are clearly vulnerable to their attrac­tion. Although a myriad of substances are available, only a few are commonly used, and all tend to produce similar harms upon the individual and society. This chapter will provide a general approach to managing a patient presenting with a problem stemming from substance misuse. It is extremely difficult to gather accurate data on the use of substances in the general population, especially if they are illegal. It is therefore likely that most figures are underestimations of the true incidence. The WHO estimates that tobacco, alcohol, and illicit drugs are a factor in 12.4 per cent of all deaths worldwide. This is a stark reminder of the severity that problems associated with substance usage can reach, but the morbidity sur­rounding them affects a much wider section of society. In the UK, 80 per cent of adults drink alcohol, 19 per cent smoke tobacco, and 30 per cent admit to having used an illegal drug at least once in their lifetime. Worldwide, the highest prevalence of drug misuse is found in the 16- to 30- year age group, with males outnumbering females at a ratio of 4 to 1. Table 29.1 shows a selection of epidemiological figures associ­ated with commonly used substances. Substance misuse is associated with an array of con­fusing terminology, the majority describing different disorders that may occur due to use of any substance. The following terms are internationally agreed and ap­pear in major classification systems:… ● Intoxication is the direct psychological and physical effects of the substance that are dose dependent and time limited. They are individual to the substance and typically include both pleasurable and unpleasant symptoms.

Eating disorders

The term ‘eating disorder’ describes a range of conditions characterized by abnormal eating habits and methods of weight control which lead to a significant impairment of psychological, social, and physical functioning. Eating disorders are serious, complex conditions; they are not simply a problem of eating too much or too little, or an attempt to achieve the perfect physique. Anorexia nervosa has the highest mortality of any psychiatric disorder, and it is notoriously difficult both to engage eating- disordered patients, and to treat them success­fully. There is a positive association between early diag­nosis and prognosis, so the skills to recognize an eating disorder— whether they present with psychological or physical symptoms— are essential for all clinicians. At the time of writing, the description of eating dis­orders within diagnostic classification systems has been undergoing considerable change. Under the ICD- 10 and DSM- IV classification systems, three main eating disorders were recognized (Fig. 27.1): … 1 anorexia nervosa; 2 bulimia nervosa; 3 eating disorder not otherwise specified (EDNOS). … However, this classification has been shown to have various difficulties: … ● The majority of cases were attracting an ‘EDNOS’ label, whereas it was supposed to be a residual category (Fig. 27.1). ● EDNOS contained within it the subdiagnosis ‘binge eating disorder’ (BED). Recent research has demonstrated BED accounts for approximately 10 per cent of eating disorders in clinical cohorts. ● The categorical nature of the system does not allow for the fact that most eating disorders change over time, and frequently move back and forth along the spectrum of presentations. ● The DSM- 5 classification system (see ‘Further reading’) has tried to tackle the first two of these difficulties, and the upcoming ICD- 11 will echo these changes (Table 27.1) There is now a separate category for BED, and three other defined conditions. This is a positive change, but has only reduced the ‘NOS/ unspecified’ percentage to some extent, and has not considered the changeable nature of eating disorder symptomatology. Hopefully in the future a solution to the difficulty of turning a spectrum of pathology into a categorical system will emerge.

Reactions to stressful experiences

In biological terms, stress literally means a force from the outside world acting upon an individual, and is a phenomenon we have all experienced. The term ‘stress’ was first used in the 1930s by the endocrin­ologist Hans Selye to describe the responses of la­boratory animals to various stimuli. Originally, Selye meant ‘stress’ to be the response of an organism to a perceived threat or ‘stressor’, but the term is now used to mean the stimulus rather than the response in some cases. When presented with a stressor of any type, everyone will produce a reaction to that stress, and this is a normal physiological event. However, if the reac­tion is prolonged, too intense, or atypical in some way, stress can become abnormal and cause problems. Stressful events, even when reacted to normally, are important contributors to the causes of many kinds of psychiatric disorder. In this chapter, we consider those psychiatric disorders that are specific reactions to stressful experiences. These may occur independently or alongside other psychiatric conditions and include: … ● acute stress reactions: short- term disorders after stressful events; ● post- traumatic stress disorder: a disorder following exceptionally severe stress; ● adjustment disorders: conditions occurring after a change in life circumstances; ● grief reactions: the normal and abnormal responses to bereavement; ● reactions to special kinds of acute stress: for example, traffic accidents, war, earthquakes, etc… For all these conditions, an identifiable stressor is a necessary but not always sufficient factor in its aetiology. GPs encounter the vast majority of patients with stress disorders who present to the health services, but all clinicians will see these patients in their clinical specialties. The reasons for this are threefold: … 1 Acute physical illness and its treatment are stressful. 2 Chronic illness or disability can result in substantial changes in life circumstances. 3 Clinicians treat people involved in other kinds of stressful experiences…. Everyone reacts to stress differently, and what consti­tutes a stressful event is therefore highly subjective. However, there are certain situations that are likely to be experienced as stressful by anyone. The Holmes and Rahe Stress Scale is a list of 43 life events which predispose to stress- related illnesses, weighted ac­cording to their respective probability of doing so.

Child and adolescent psychiatry: general aspects of care

Child and adolescent psychiatry is a broad dis­cipline relevant to any health professional who has regular contact with young people. Childhood emotional, behavioural, and developmental prob­lems are common, especially in children with other medical or social difficulties. This chapter aims to provide an approach to child mental health diffi­culties, while Chapter 32 deals with common and/ or important psychiatric disorders that are specific to childhood. You may find it helpful to revise some basic child development— this can be found in any general paediatrics text (see ‘Further reading’). An overview of the differences between child and adult psychiatry is shown in Box 17.1. As in adult psychiatry, diagnosis of psychiatric dis­orders often relies on the clinician being able to recog­nize variants of and the limits of normal behaviour and emotions. In children, problems should be classified as either a delay in, or a deviation from, the usual pattern of development. Sometimes problems are due to an excess of what is an inherently normal characteristic in young people (e.g. anger in oppositional defiance disorder), rather than a new phenomenon (e.g. hallu­cinations or self- harm) as is frequently seen in adults. There are four types of symptoms that typically pre­sent to child and adolescent psychiatry services: … 1 Emotional symptoms: anxiety, fears, obsessions, mood, sleep, appetite, somatization. 2 Behavioural disorders: defiant behaviour, aggression, antisocial behaviour, eating disorders. 3 Developmental delays: motor, speech, play, attention, bladder/ bowels, reading, writing and maths. 4 Relationship difficulties with other children or adults…. There will also be other presenting complaints which fit the usual presentation of an adult disorder (e.g. mania, psychosis), and these are classified as they would be in an adult. Occasionally, there will also be a situ­ation where the child is healthy, but the problem is ei­ther a parental illness, or abuse of the child by an adult. Learning disorders are covered in Chapter 19. Table 17.1 outlines specific psychiatric conditions diagnosed at less than 18 years, and Box 17.2 lists general psychiatric conditions that are also commonly found in children.

Thinking about prognosis

The prognostic assessment of a patient aims to pre­dict the future, using the range of evidence available. This evidence relates to: … ● the individual patient (e.g. their own history of illness, and their compliance with medication); ● groups of patients like the individual patient, that is, diagnostic and subdiagnostic groups (e.g. in depressive disorder, the risk of recurrence; and in anorexia nervosa, the risk of suicide or of death by starvation); ● psychiatric patients in general (e.g. the importance of good relationships with healthcare professionals, supportive family and friends, and insight into illness). … Prognostic assessment results in an understanding of the following: … ● What outcomes are likely to happen? Relevant outcomes can be related to the illness (relapse and recurrence, for example— see ‘Terminology’ for definitions), to treatments (such as side effects or complications), to risks (to self, to others— see Chapter 7), or to important social outcomes (such as return to work, marital break- up, or permission to drive a car, bus, or lorry). ● How likely are they to happen, and when/ over what time period? An estimate of both likelihood and timeline is helpful. So, for example, in a patient with recurrent depressive episodes, who is now well, we may view that their lifetime risk of suicide is significantly higher than the population risk, that they are not currently at increased risk, and that suicide attempts are likely to occur in the context of depressive recurrence. ● What can change the nature or likelihood of the outcomes? For example, in the case just mentioned, we may view that the lifetime risk of recurrence can be reduced by training the patient and family to spot the early warning signs of illness, by reducing daily consumption of alcohol, and by finding regular, stable employment. In addition, we can reduce suicidal risk by ensuring that the patient is prescribed medicines that are relatively safe in overdose (e.g. SSRI antidepressants rather than tricyclics), and by making family members aware of the risk of their own medication being used in an overdose.

Thinking about aetiology

Doctors need to be able to combine scientific know­ledge with empathic understanding in order to form a coherent account of their patients, their illnesses, and their difficulties. In this chapter, we will de­scribe how this can be achieved in the assessment of the aetiology (cause or causes) of a patient’s disorder. A knowledge of the causes of psychiatric disorders is important for two main reasons: … ● It helps the doctor to evaluate possible causes of an individual patient’s psychiatric disorder and life difficulties. This is the focus for this chapter. ● It adds to the general understanding of psychiatric disorders, which may contribute to advances in diagnosis, treatment, or prognosis. This is reviewed in subsequent chapters…. When assessing aetiology in a particular patient, we usually structure this by talking of predisposing, precipitating, and perpetuating (often called maintaining) factors (see Fig. 7.1 and Box 7.1). These ‘three Ps’ are often supplemented by a fourth P: protective factors. These terms are used most commonly in psychiatry and related disciplines. However, the principles are broadly applicable in medicine. We therefore recommend that you prac­tise their use in long- term physical conditions such as diabetes, asthma, and vascular disease. Predisposing factors determine vulnerability to other causes that act close to the time of the illness. Many predisposing factors act early in life. Physical factors, for example, include genetic endowment, the environ­ment in utero, and trauma at birth. Psychological and social factors in infancy and childhood are also rele­vant, such as bullying at school, abuse in its various forms, and family stability. Such factors lead to the de­velopment of a person’s ‘constitution’, which leads to wide variability, at a population level, in vulnerability to disorder: some people are highly vulnerable, some are highly resilient, and most are somewhere in be­tween. Some personality traits increase vulnerability to specific disorders— for example, obsessional traits predispose to depressive illness, perhaps because the challenges and uncertainty of everyday life inevitably lead to disappointment for those seeking order and perfection at all times. Precipitating factors are events that occur shortly before the onset of a disorder and appear to have induced it. Again, these may be physical, psy­chological, or social. Physical precipitating causes include diseases such as hypothyroidism, myo­cardial infarction, breast cancer, and stroke, and the effects of drugs taken for treatment or used il­legally.