Depression, the leading cause of disability worldwide, is the focus of 2017 World Health Day. To honor the day, Oncology Central spoke with Christopher Sharpley from the University of New England (New South Wales, Australia) about his research into uncovering novel treatments for depression in prostate cancer patients and his hopes for the future of the field.
Could you tell us about your career to date?
I began my working life as a teacher, then a Psychologist and then undertook postgraduate training in research, moving to become a university academic in my early 30’s. After a career of nearly 30 years at Monash University (Melbourne, Australia) and Bond University (Queensland, Australia), I retired as Professor of Health Sciences in 2004. However, I soon became bored and returned to further study (BSc, MSc) in 2007 – 2011. I then recommenced my academic career as Professor of Neuroscience at the University of New England (New South Wales, Australia).
One of your projects focuses on how hormone therapy affects the mental well-being of prostate cancer patients. Could you tell us a bit more about the aims, findings and implications of this project?
Hormone therapy (HT) is used to good advantage in treating some types of prostate cancer but has been known to induce side effects including anxiety and depression. In a recent study published in Psycho-Oncology  we demonstrated that the origin of the elevated depression scores by patients on HT was really reliant on the effects that this treatment had upon their erectile function. That is, they were unable to achieve satisfactory erections and this made them unhappy due to loss of sexual pleasure. However, although that lifted their depression scores, it did not mean that these men were clinically depressed in the usual sense because they did not show similar increases in the other symptoms of depression. So, we argued on the basis of these findings that the depressive effects of HT might be best understood as being associated with “anhedonia” (loss of pleasure) in one specific aspect of their lives rather than global sadness or depression per se. It’s also important to note that these ‘depressive’ effects will probably decrease after the end of HT for most patients.
Are there any steps clinicians can take to maintain the mental well-being of prostate cancer patients?
Yes, as suggested above, clinicians should (a) be aware that the ‘depressive’ effects of HT may be confined to just loss of pleasure in sexual activity rather than pervading sadness or depressed mood and that this limited anhedonia does not really constitute the kind of global loss of interests and enjoyment that is necessary to achieve full-blown depression; (b) they should tell their prostate patients about this; and (c) they could also encourage patients to explore alternative sexual interaction procedures with their partners during the HT period.
You have previously researched the role of melancholia in prostate cancer patients’ depression . Could you tell us about your findings?
This was really a step along the way to the findings reported above on HT. That is, we noted that our patients suffered from symptoms of anhedonia rather than depressed mood and those anhedonia symptoms are also a key aspect of melancholia. It is of interest that in that earlier study , we found no clear association between HT and anhedonia or melancholia. Thus, it may be that the underlying loss of sexual function and enjoyment found in HT patients might also be present in patients who received other treatments such as surgery and radiotherapy. There are some reports about the rates of impotence in patients who receive these treatments and it may be that the core issue for these men (regardless of treatment type) is the damaging effect that treatment has upon their ability to get and maintain an erection and their consequent loss of sexual pleasure. If this is the case, then much of the work that goes into providing counselling support for these patients should also consider simple information about the effects of treatment and ways to find alternate sexual expression pathways and satisfaction.
You have also researched the utilization of cluster analysis of anxiety-depression to identify subgroups of prostate cancer patients for targeted treatment planning  ?
We demonstrated that patients could be grouped into three clusters according to the type of anxiety-depression symptoms they experienced. This is important because it means that the distress experienced by some prostate cancer patients needs to be conceptualized as being comprised both anxiety as well as depression, rather than just depression. It’s also very important because it means that just using the total score from an inventory of anxiety or depression to classify a patient’s mental state will miss the details of his condition and will probably result in a less effective treatment than otherwise. Both of these disorders are linked by common symptoms but this paper identified how the combined list of symptoms could be split into three groups. The three groups (or “clusters”) were built on the basis of the symptoms of “feeling down, depressed, or hopeless” (which are symptoms of depression), “worrying too much about different things” and “not being able to stop or control worrying” (which are symptoms of anxiety). The implications of these findings are that clinicians should not focus upon the total score from a depression inventory but should also explore the specific symptom scores, and should also include symptoms of anxiety as well.
What advancements would you like to see in the field of treating depression in cancer patients in the next 5–10 years?
As suggested in my answers to several questions above, I would like to see the development of “individualized medicine” approaches to diagnosing and treatment prostate cancer patients’ mental health states rather than simplistic approaches that aim to be equally effective with what is a wide range of symptomatology. There is an abundance of literature that (a) reports that approximately 30% of these men will become clinically depressed , with many more suffering from subclinical depression (which can be just as debilitating as Major Depression  and (b) not all depressions are the same . Using the total scores from clinical interviews and/or self-report inventories will disguise the actual symptom profiles of depression in these men and does not allow for the incorporation of the presence of anxiety, which we found was a major aspect of their distress. Oncologists may not have the time or focus to deal with these aspects of prostate cancer but they should at least refer all patients for a mental health screening. Whoever does that screening should examine patients’ responses at the symptom level as well as at the total score level. Finally, “off-the-shelf” or manualized treatments do not recognize the variation in patients’ anxiety-depression symptoms profiles and the resultant need for targeted treatments that address patients’ symptoms.
Do you have any closing comments for our readers?
The sort of “one-size-fits-all” approach that relies on treatment manuals is out of date and irresponsible today. Although those treatments were helpful in standardizing therapy in the past in research studies, they now need to be replaced by truly individualized treatment models in clinical settings. To do less is unethical.
After 10 years as a school teacher, Chris trained as a clinical psychologist and taught psychological assessment and psychotherapy at Monash University and Bond University for 20 years. He was Professor of Clinical Psychology and Health Sciences and the Founding Dean of the Faculty of Health Sciences & Medicine at Bond University. He then retrained as a Neuroscientist and is currently Professor of Neuroscience within the School of Science & Technology. His particular research interests are in the interface between the neurobiology and clinical manifestations of depression and clinical aspects of depression in Autism Spectrum Disorder.