The Origins and Course of Common Mental Disorders

Prof David Goldberg, Ian M Goodyer

• Publisher: Routledge
• Year: 2014
• eBook ISBN: 9781317821984
• Topic: Psychology
• Subtopic: History & Theory in Psychology
• Index: Psychology

Why are some people more vulnerable to common mental disorders than others?

What effects do genes and environments exert on the development of mental disorders?

The Origins and Course of Common Mental Disorders describes the nature, characteristics and causes of common emotional and behavioural disorders as they develop across the lifespan, providing a clear and concise account of recent advances in our knowledge of the origins and history of anxious, depressive, anti-social, and substance related disorders.

Combining a lifespan approach with developments in neurobiology, this book describes the epidemiology of emotional and behavioural disorders in childhood, adolescence and adult life. David Goldberg and Ian Goodyer demonstrate how both genes and environments exert different but key effects on the development of these disorders and suggest a developmental model as the most appropriate for determining vulnerabilities for psychopathology. Divided into four sections, the book covers:

the nature and distribution of common mental disorders
the biological basis of common disorders
the human life cycle relevant to common disorders
the developmental model.

This highly readable account of the origins of emotional and behavioural disorders will be of interest to behavioural science students and all mental health professionals including psychiatrists, psychologists, social workers, nurses, and counsellors.

Part I

---

The nature and distribution of common mental disorders

---

Chapter 1

---

Competing models for common mental disorders

---

Categorical models of common mental disorders

The conventional taxonomy of mental disorders is that set out in the fifth chapter of the World Health Organisation's International Classification of Disease, tenth edition (WHO 1988: ICD-10). This is broadly comparable to the fourth edition of the American Psychiatric Association's (1994) Diagnostic and Statistical Manual, fourth edition (DSM-4).

These classifications are arrived at by consensus meetings of distinguished psychiatrists, either in Geneva or in Washington. They are essentially arbitrary, ‘top-down’ classifications — and they are necessarily revised at regular intervals, as new treatments become available, as new mental disorders emerge, or as research findings indicate heterogeneity within diagnostic entities.

Inevitably, it is easier to reach consensus about major, severe disorders that are worldwide in their distribution — like dementia, mental retardation, schizophrenia and bipolar disorder. It is far more difficult to achieve consensus about the common mental disorders, where cultural factors and differing diagnostic habits dictate different patterns of common symptoms of mental distress.

Thus, ‘brain fag’ (Africa), ‘kidney weakness’ (China), ‘Jibyo’ (Japan), ‘burn-out’ (USA), ‘chronic fatigue’ (UK) or ‘neurasthenia’ (Asia) are all ways of referring to syndromes of disordered function in various parts of the world that have no known organic pathology. One solution to this otherwise intractable problem is to impose the diagnostic concepts that have been agreed by senior psychiatrists upon general physicians in the rest of the world. These concepts are heavily influenced by American and European psychiatrists, and may do less than justice to the forms of disorder in other parts of the world.

It should cause no surprise that different diagnostic systems assign quite different diagnostic labels to the same patients, or even to distinguish between cases and normals. In community surveys that have used more than one categorical system to classify people, Surtees et al. (1983) found agreement in only 61 per cent in Edinburgh; Grayson et al. (1990) in only 65 per cent in Manchester; and in only 72 per cent in the Netherlands.

Within the group of cases by both systems, agreement about diagnosis was even worse: for example, Surtees found agreement in only 16.7 per cent of ‘anxiety’ patients, and 56 per cent of ‘depressed’ patients, Grayson and his colleagues found agreement in 25.6 per cent and 50 per cent in Manchester, UK, and van den Brink and others (1990) found agreement in 47.5 per cent and 57.5 per cent of these groups. Those investigators using a single categorical system, triumphantly produce figures of specious accuracy.

A further problem is that these categories do not occur on their own, but in combinations with other disorders: thus Angst and Dobler-Mikola (1985) calculated that combinations were nine times more likely than chance in depression, five times in panic, and 3.5 times for anxiety. American investigators solve this problem by portentously announcing that different disorders are ‘co-morbid’ with one another: thus, a person who has sufficient symptoms of both anxiety and depression is declared to have ‘major depressive disorder co-morbid with generalised anxiety disorder’. Thus, the National Co-morbidity study in the USA shows a ‘co-morbidity’ between depression and anxiety over 12 months as 57.5 per cent (CI 53–61.7) (Kessler et al. 2003).

It is also of interest that many of the social characteristics of anxious and depressive states overlap with one another: Eaton and Ritter (1988) using the Diagnostic Interview Schedule in the Epidemiologic Catchment Area survey in Baltimore found that the socio-demographic characteristics were similar, the associations between the scale scores and the presence of alcohol problems, drug abuse, schizophrenia and anti-social personality were the same, and so were the associations between scale scores and stressful life events.

A final problem with categories of common disorders is that they do not exhibit consistency over time. Cases of morbid anxiety may be mingled with episodes of depression, may be complicated by predominant obsessional symptoms or hypochondriacal preoccupations at some times but not others: such longitudinal changes in common mental disorders have been documented by numerous investigators over the past 25 years (Eaton and Ritter 1988; Lee and Murray 1988; Andrews et al. 2001; Angst 1990; Goldberg et al. 1998).

A somewhat different approach to internationally agreed diagnostic rules is to use a kind of multivariate analysis called ‘Grades of Membership analysis’. In this approach, subjects who report two of the core symptoms of depression are recruited to study the natural grouping of symptom clusters that emerge in that particular population. An example of this approach would be Blazer and others (1988) examination of 406 people complaining of at least two depressive symptoms, selected from a much larger population in North Carolina. Five ‘fuzzy’ types of patient emerged:

1 A mild dysphoric group 197

2 An elderly cognitively impaired group 83

3 A predominantly depressed group 44

4 A predominantly anxious group 43

5 A group of women with premenstrual symptoms 39

This is an interesting approach since pattern of symptoms found in one country is not being applied, willy-nilly, to another setting. The fuzzy categories that emerge can indeed be cross-tabulated with conventional categorical diagnosis. Notice that a ‘predominantly anxious’ group emerges despite the fact that subjects were selected because of depressive symptoms. However, to adopt this approach internationally would substitute a cacophony of different ‘fuzzy’ groups for the Esperanto of internationally agreed diagnostic rules.

Faced with these apparently unsolvable problems, it may be wondered why categorical models live on. They live on because they are needed. Public health physicians need to compare the health of one population with another, and health managers need to plan mental health services. Working clinicians who wish to offer a structured psychological intervention or a pharmacological intervention must decide whether the individual who has sought their help needs one, or some other, intervention. Also, the diagnostic label frequently justifies the intervention offered; and many people like to know what the clinician thinks is wrong with them if they are to collaborate with a treatment programme. Arbitrary diagnostic labels fulfil this function admirably.

The rules adopted to justify categories are on the whole fairly arbitrary, but then they always are in medicine where a continuously distributed quality is concerned — blood pressure, anaemia or body mass index are all examples — morbidity and mortality increase as one ascends the scale, but the cut-points adopted are determined by the resources available in the health system to investigate and subsequently treat the patient. In 1960, for example, we tolerated a diastolic blood pressure of up to 110 mm mercury in a man, and 120 mm mercury in a woman. It is now possible to treat any diastolic blood pressure above 90 mm: the cost and difficulty of the investigations has decreased and more effective drugs are available — but the phenomena of hypertension have not changed.

The ICD-10 classification allows an interesting modification to a simple dichotomous diagnosis, by dividing depression into four categories: not depressed, mild, moderate and severe depression. This is sensible if there is evidence that different treatment regimes are effective with depression at various levels of severity. In the case of depression, there is accumulating evidence that this is indeed the case.

Dimensional models of common disorders

Aubrey Lewis (1934) wrote that anxiety was a common, and probably integral, part of the depressive reaction, and this accords both with clinical experience and with many different data sets dealing with the distribution of common symptoms in general populations. Adolf Meyer (1955) taught that the individual patient is unique, and can neither be broken down into separate aspects nor categorised into categories of disease entities. His emphasis on understanding the sick individual is called the idiographic method, in contrast to approaches which concentrate on how groups in sick individuals resemble one another, called the nomothetic approach.

It should not be thought that clinicians should be obliged to adopt one approach or the other: the former is indispensable for understanding what Karl Jasper (1963) had earlier referred to as ‘the whole man in his state of sickness’, while the latter is essential if knowledge is to advance concerning the advantages of one treatment over another.

Syndromes, symptoms and dimensions of symptoms

It is important to distinguish between categorical notions of mental disorders, which are themselves syndromal, in that they consist of collections of symptoms observed by clinicians, and dimensional models which are exploring t...

Table of contents

• Cover Page
• Half Title Page
• Title Page
• Copyright Page
• Contents
• Figures
• Tables
• Foreword
• Introduction
• Part I The nature and distribution of common mental disorders
• Part II The biological basis of common disorders
• Part III The human life cycle relevant to common disorders
• Part IV The model proposed
• References
• Author index
• Subject index