The authors set themselves the difficult task of deconstructing the prevailing view of depression in the context of medical illness. The World Health Organization raises awareness of depression as the leading cause of disability worldwide and research over the past few decades has increasingly shown that, more frequently than not, depression goes hand in hand with multiple common medical conditions. As the role of antidepressants is questioned and the concept of ‘difficult-to-treat’ depression becomes widespread, they approach a significant theme that is often missed when considering patients with depression.

The authors address primary care physicians (PCPs) as their main audience and note how important it is that PCPs are able to take a holistic approach to depression and consider it in the context of their patients’ other illnesses. However, many other clinicians, including psychiatrists, are likely to benefit from looking through the content of this book. It starts with a review of the most recent biological models of depression, then moves on through the role of epigenetics and systemic hormones in this disorder. With health professionals as the main audience, basic knowledge of neuroscience, neuroendocrinology and immunology is assumed and a reader without this might struggle in the initial chapters.

The biological effects of depression in medical conditions such as cardiac illness, stroke, cancer, neurological disorders, diabetes and wound healing, and the bidirectionality of depressive disorders are covered. The short chapters with multiple subsections enable the reader to quickly navigate through information and pace their reading without having to tackle long sections. This is combined with a review and summary of the most significant research, allowing the reader to quickly become acquainted with the themes.

Included in the book is a brief course on psychopharmacology. Although not meant as a prescriber's guide, the tables addressing side-effect profiles and metabolic enzymes are useful. The book ends with a review of models of mental health training for non-psychiatrists and how electronic health records may be used for better management of depression.

Depression as a Systemic Illness is not a light read but will capture the reader's interest as it guides them on a systematic and concise journey culminating in a more comprehensive understanding of depression as an illness rather than an isolated disorder.