Preface

Despite the many myths, legends, anecdotes, and apocryphal stories that frequently surround psychiatry and its practitioners, it nonetheless remains a branch of medicine, albeit with influences from a wide range of other, diverse fields. It should therefore come as no surprise that the pathology laboratory plays an important role in the diagnosis and management of a number of psychiatric disorders. While there is at present no single, specific laboratory test for any psychiatric disorder, the laboratory nevertheless helps clinicians to exclude important, treatable causes of psychiatric morbidity and assists with appropriate treatment strategies. For example, whilst a psychotic patient may be initially thought to have schizophrenia, the laboratory can assist in the exclusion of diverse causes of psychosis such as infection, neoplasm, or sequelae of substance abuse. In addition, many of the medications used to treat this psychotic patient may have a range of adverse metabolic effects, which are amenable to, or indeed require, laboratory monitoring.

At present there does not appear to exist any specific single book in current use that addresses the often close association between laboratory medicine and mental health. There are, however, at least two previously published volumes dedicated to laboratory testing in psychiatry. The first of these ¹ provides an excellent, if perhaps out of date, overview of the field, but is not intended as a handbook for front-line clinicians. The second one ² is designed as a pocket handbook but is, again, out of date and does not, for example, consider the metabolic associations or therapeutic drug monitoring aspects of the newer psychotropics.

The current book therefore aims to fill this gap, and is intended as a basic guide to laboratory aspects of mental illness in the non-pregnant general adult population, generally taken to include the age range from 18 to 65. It focuses specifically on those aspects of psychiatry amenable to laboratory involvement and is not designed as a definitive textbook of general medicine, laboratory medicine, pathology, psychiatry, or psychopharmacology. Whilst it aims to span and complement these related disciplines, appropriate specialized texts or expert advisors should always be consulted for further information as required. The reader should also note that treatment will not be discussed in this book (except briefly in Chapters 3 and 5) as this should be undertaken after consultation with the appropriate experts and/or those with appropriate experience.

This book aims to cover the bulk of the important disorders that will be seen by the general-adult psychiatrist. Rarer conditions and most organic brain syndromes (neuropsychiatric syndromes) are excluded as these are covered in appropriate detail elsewhere. Additionally, other important investigations (imaging, electrophysiology) are not described here as they are felt to fall outside the remit of the pathology laboratory.

It is hoped that this book will initially be of utility for those two usually disparate groups of professionals, namely pathologists and psychiatrists. Additionally, the book should prove useful for general practitioners, pharmacists, nurses, medical students, doctors in training, laboratory staff, specialists in internal medicine, researchers, and others. To help non-mental-health workers understand psychiatric nosology, details of selected psychiatric conditions are included in order to assist, at least in part, in understanding the complexity of psychiatric disorders and presentations and why clinicians may request particular tests and investigations.

Where appropriate, definitions of specific psychiatric disorders will be based mainly on ICD-10 (International Statistical Classification of Diseases and Related Health Problems, 10th Revision) criteria with only occasional reference to DSM-IV ( Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition ). Equally, details of selected medical presentations will be included to provide useful background as well as to assist with appropriate laboratory investigation and diagnosis.

Whilst every effort has been made to reflect current knowledge and minimize errors, it should be recognized that both psychiatry and laboratory medicine are ever-changing fields, and no liability can be accepted for inaccuracy, incompleteness, injury, damage, or loss. Where possible, the most recent guidance published by the UK National Institute for Health and Clinical Excellence (NICE) will be quoted.

Finally, this book is all my own work and is an entirely independent production. I have not received any commercial or institutional support, sponsorship, or other input and consequently have no declarations of, or conflicts of, interest.

1. Gold MS, Pottash ALC. Diagnostic and Laboratory Testing in Psychiatry. New York: Plenum Publishing Corporation, 1986.

2. Rosse RB, Giese AA, Deutsch SI, Morihisa JM. Concise Guide to Laboratory and Diagnostic Testing in Psychiatry. Washington, DC: American Psychiatric Press, 1989.