A person suffering from schizophrenia is often in double jeopardy. While enduring the direct consequences of this devastating mental disorder, the individual with schizophrenia also has to bear a much higher burden of physical disorders than others in the general population. Stefan Leucht and colleagues systematically catalogue in this book all the physical co-morbidities that have been associated with schizophrenia. This knowledge in itself is not new and over the last 100+ years, numerous studies have documented this. However the major studies have typically focused on the epidemiology of the co-morbidity, and case reports discuss treatment of the co-morbid conditions. Recently, the second-generation antipsychotics have been associated with weight gain and the metabolic syndrome, and a body of literature has sprung up examining the increased risk for cardiovascular and metabolic disorders in schizophrenia. There is, however, no single comprehensive work that brings this vast literature together in one place, and this book attempts to fill the void. As such, this is a valuable addition to our libraries and can serve as a quick reference to check-up on the co-occurrence of a vast array of specific physical disorders with schizophrenia. This exhaustive listing, however, comes with a price, namely that the material presented for most illness groups is limited, and there is typically minimal discussion of the reasons for, and implications of the co-morbidity. Additionally, all co-morbid conditions are treated alike, as if their medical import is equal, which it is not. For example, Borelliasis, ‘dental disease’ and ‘temporomandibular joint disease’ get the same amount of space and discussion as autoimmune disorders, epilepsy and deafness. The reader will recognize that the latter disorders have major aetio-pathological, treatment, and quality-of-life implications in schizophrenia, while the former do not. Thus, to paraphrase a common cliché, while thoroughly and precisely counting the trees, the authors miss the landscape of the co-morbidity forest. In fact, there are 84 small sections devoted to individual disorders or groups of disorders! Therefore, the reader is likely to get bogged down with the minutiae of various rates of this exhaustive listing of disorders and possibly put away the book for another day.
The best part of the book is the Preface (page ix), introduction (pages 1–2), and the last 2 pages of chapter 4 (Discussion). In these, the authors highlight the sad fact that psychiatrists are reluctant to treat physical illness and their medical skills become rusty soon into their psychiatric practice. On the other hand internists and medical specialists often fail to adequately recognize mental disorders and when they do, under-treat them. Integration of medical skills into psychiatric practice and psychiatric skills into medical practice is badly needed. The brief mention of these deficiencies is insufficient given the paramount importance of these issues and the overwhelming costs of co-morbidity. The authors have simply missed out on the opportunity to present the policies, procedures, educational needs, personnel, logistics, and costs and benefits of integrated treatment models as well as the current state-of-this-art, and to inform the readers what works and what does not. While the Preface mentions briefly what needs to be done, the reader looking for a more thorough discussion in subsequent chapters will be disappointed to find there is none.
The methodology utilized in documenting the various co-morbidities is an extensive literature search resulting in more than 475 references. Sections 3.1 to 3.23 form the bulk of the book and list the results of the literature search, with brief comments by the authors. The sections on HIV, cancer, cardiovascular disorders, diabetes, obstetric complications, rheumatoid arthritis and cancer are more thoroughly covered and well referenced, with extensive tables. Disorders with higher prevalence in schizophrenia seem to fall into two categories – (1) those that could be attributed to the lifestyle of persons with schizophrenia, for example HIV, obstetric complications, obesity, cardiovascular disorders, diabetes and sleep disorders, and (2) those that may have a subtle but more direct aetio-pathological connection, for example neurodevelopmental abnormalities, autoimmune disorders, epilepsy and hearing impairment. Interestingly, there are a few disorders with a reported lower prevalence in schizophrenia, such as rheumatoid arthritis, myasthenia gravis, certain cancers and pain syndromes. It is not clear whether somehow the biology of schizophrenia offers a protection against these disorders, or that schizophrenia patients with these disorders seek treatment less often and hence remain under-reported. Again this reviewer sincerely wished that these interesting data were ploughed through more thoroughly and their broader implications were presented.
The authors chose to exclude mortality studies and iatrogenic conditions such as adverse effects of medication. This is quite disappointing. If colleagues in medical specialities are to be impressed with the seriousness of physical co-morbidity in schizophrenia, it is by learning the high mortality rates. Likewise, leaving out iatrogenic illnesses from the otherwise exhaustive review misses another opportunity of informing practitioners and policy makers of the very conditions that are most preventable, since they are caused by us. It is this reviewer's impression that our medical colleagues are more eager to learn about co-morbidities that they can do something about, than risk factors that are beyond the practitioner's immediate control. For example, it is more useful to know of the risk of death from benzodiazepines prescribed to a schizophrenia patient with co-morbid sleep apnoea than it is to be aware of the rates of chlamydiasis, Gilbert syndrome, urinary incontinence, etc.
All in all, a quick and easy reference guide and a good starting point for trainees and readers interested in co-morbidity but one that does not fully address the challenges of co-morbidity nor exploit the potential for advancement of knowledge from its study.
