Mental health and chronic diseases: a challenge to be faced from a new perspective

Introduction

In modern psychiatric classification systems, it is possible that a mental disorder (such as depression, anxiety, or bipolar one) may be classified as ‘due to another medical condition’. In the case of DSM-5, this diagnosis is made when ‘there is evidence from the history, physical examination, or laboratory findings that the disturbance is the direct pathophysiological consequence of another medical condition’ (American Psychiatric Association [APA], 2013).

This approach has an intrinsic contradiction: A descriptive classification system, by definition, should not take account of the aetiopathogenesis of the disorder. In fact, in this case, the diagnosis is a consequence of an aetiopathogenic criterion (the disorder is due to a general medical condition). If we consider that we still do not abandon a classification based solely on syndromic description because we don’t know the causes of psychiatric diseases, it seems bizarre that such a classification identifies a certain type of disturbance as ‘caused by’.

The papers that follow in this special themed issue explain in detail how specific chronic diseases may alter that balance of factors that produce psychological well-being. The ways in which, in each chronic disease, a psychiatric disorder can occur are incredibly complex. Thus, it is very difficult, at present, to say when a mental disorder is caused by another condition, when common factors may have influenced the onset of both diseases. Furthermore, when these conditions are so interconnected that it is entirely possible to suppress the ‘other condition’, the mental disorder is regarded as a single entity.

The presence of co-morbidity with a mental illness, however, connotes another chronic disease in a way that cannot be ignored.

Despite the different and specific mechanisms that can lead to a mental disorder before (as first onset syndrome), during, or as a result of another chronic disease, mental illnesses may also affect compliance to treatment for the other disease. Medication for these co-morbidities may lead to drug interactions. The conditions may affect biorhythms, thereby influencing compliance and outcomes. Hence, underlying vulnerabilities to mental disorders, be they biological, genetic, or social, need to be taken into account while studying the genesis of co-morbidities, but also in planning therapeutic interventions. For example, using corticosteroids in Multiple Sclerosis or Rheumatologic Diseases indicated the side-effects may lead to mood disorders. It is also evident that the course of a mental disorder in co-morbidity with another chronic disease is, on average, different from the course of a similar disorder without co-morbidity. The co-existence of a disorder like depression is the major determinant of disability and impaired quality-of-life in many chronic diseases, and it has been shown that, unless both conditions are treated at the same time, the response to treatment may well be poor.

All of this contrasts with the reality that the majority of clinical trials on the effectiveness of the treatments are conducted with criteria that exclude patients with co-morbidity, and that very few studies have focused specifically on the conditions in which a mental illness appears with another chronic disease, even though, in many chronic diseases, the coexistence of a disorder like depression is the major determinant of disability and impaired quality-of-life.

The impact of these phenomena is so vast that a new focus to the issue of co-morbidity is required.

This special themed issue aims to contribute to this need, focusing on specific fields that could be considered as models more than an exhaustive treatise on the whole field. The authors have offered cross-cutting themes and generalities, as well as contrasts between the various conditions examined. While not an exhaustive treatise, this set of papers, taken together, is more than the sum of its parts.

Specific topics of interest

Grassi, Mezzich, Nanni, Riba, Sabato, and Caruso (2017), in this volume, point out clearly how all the technical progress should be brought back to a user-centric model. The work highlights that those involved in the care must not forget the human dignity dimension of the suffering. The right to approach patients as persons, rather than symptoms of diseased organs, must be recognized, especially in complex situations, technically challenging though it may be, e.g. those of comorbid psychiatric disorders with other chronic diseases. In fact, Caruso, Nanni, Riba, Sabato, and Grassi (2017) deal with the burden of co-morbidity of psychiatric disorders in cancer. One essential point that they develop and emphasize is that such a frequent condition of comorbidity (affecting ∼30% of people diagnosed with cancer) is reflected through its impact on the nuclear family. The authors remind us that a family approach is needed in cancer care, introducing the caregiver-patient dyad as a unit to be the focus for assessment and intervention. The work reviewed here suggests the most significant psychosocial disorders causing burdens for cancer patients and their caregivers, and the authors illustrate methods for more proper referral and treatment. It should not be under-estimated that the impact of pathology like cancer can produce stress-related disorders in the person suffering from it. Ovarian cancer is one of the deadliest malignancies. This cancer also affects women in adulthood with young children. The impact of this diagnosis is, therefore, highly traumatic, and affected women are prone to significant distress during the whole course of the disease. Gesi, Carmassi, Sancassiani, Gadducci, and Dell’Osso (2017) review the literature on the relationship between ovarian cancer and Post-Traumatic Stress Disorder, an association of great clinical relevance that should be accurately identified when present.

Josephson and Jetté (2017) deal with epidemiology, clinical manifestations, and treatment considerations for co-morbid psychiatric conditions (especially major depressive disorder, anxiety, and psychosis) and epilepsy. As evidence of a higher risk of psychiatric comorbidity in focal epilepsies (especially, but not exclusively, those of the temporal region) over those of generalized epilepsy, the authors point out that pathophysiology varies. The relevant topic of suicide and suicidal ideation in epilepsy is also addressed. This paper aims also to familiarize the reader with the need for high-quality and clinically informative research on co-morbid conditions in epilepsy, and of potential application with evidence-based support for the treatment of these conditions.

Cardio-vascular diseases are a major public health challenge, and these are frequently comorbid with psychiatric (especially mood) disorders. Fornaro, Solmi, Veronese, Berardis, Buonaguro, Tomasetti, et al. (2017), in their paper, highlight that patients with cardio-vascular diseases and mood disorders suffer significant disability and mortality. The authors provide evidence that these relationships are bidirectional, due to a shared genetic risk of pathways involved in stress reactions serotonin or dopamine signalling. They quite rightly recommend that patients with cardio-vascular diseases should be routinely screened for the presence of mood disorders. Behavioural lifestyle interventions targeting nutrition and exercise, coping strategies, and information about health should be routinely provided to patients with mood disorders, to prevent cardio-vascular diseases. A narrative review of the evidence of effective treatment is also provided.

Machado, Sancassiani, Paes, Rocha, Murillo-Rodriguez, and Nardi (2017), in their paper, address the association between panic disorder (PD) and cardiovascular diseases (CVD). They show from the literature that that PD pathophysiology could cause or potentiate CVD; however, this is a causal relationship which is not well recognized or well understood. They synthesize the evidence of the mechanisms and mediators that could be responsible for the association between PD and CVD. This can increase the likelihood of new possibilities for clinical management and for understanding pathophysiological mechanisms and causality.

Wilson Disease is a rare inherited disorder causing copper accumulation in different organs, mainly the liver and brain. The systematic review by Mura, Zimbrean, Demelia, and Carta (2017) illustrates why psychiatric disturbances (especially depressive and bipolar disorders) represent a major diagnostic and therapeutic conundrum in Wilson Disease, which may contribute to lower Quality-of-Life and poorer therapeutic adherence. Therapies for this disease lead to a good life expectancy, provided therapeutic adherence is maintained with good clinical follow-up using a multidisciplinary approach, along with education about risks in those affected and their relatives. Mura et al. remind us that studying how injuries secondary to copper accumulation can produce mood disorder may be a useful model to identify pathogenic hypotheses related to mood disorder comorbidities.

Patten, Marrie, and Carta (2017) detail the comorbidity of depressive disorders and multiple sclerosis (MS) that can occur in up to 50% of people living with MS. The authors review the literature on aetiology of depression in MS, including biological mechanisms, as well as the stressors, threats, and losses that accompany living with an unpredictable and often disabling disease. The complex nature of treatment of depressive disorders in MS is addressed, although they recognize that, although the research evidence is limited, available results support the effectiveness of standard treatment approaches, including cognitive behavioural therapies and antidepressant medications. They conclude that, after reviewing the literature on the validity of standard measurement scales for depressive disorders, these are valid.

In their paper, Cossu, Carta, Contu, Mela, Demelia, Elli, et al. (2017) summarize the studies on the link between psychiatric disorders and coeliac disease. Coeliac disease is the most common autoimmune lifelong disorder in western populations (more than 1% of people suffer from this disorder), with clinical manifestations of diarrhoea, weight loss, and anaemia. Psychiatric comorbidity often makes its diagnosis difficult, which also contributes to poor quality-of-life. This co-morbidity may also affect adherence to the gluten-free diet, which is the principal treatment that needs to be introduced in the early stages of the disease. Thus, screening for psychiatric disorders in coeliac disease is essential and recommended.

Sancassiani, Machado, Ruggiero, Cacace, Carmassi, Gesi, et al. (2017), in their paper, deal with the theme of Fibromyalgia (FM), a syndrome characterized by chronic widespread pain, which often presents with comorbid psychiatric disorders, and resulting psychological distress. They review the literature about the management of FM from a psychosomatic perspective, with a focus on five main topics (diagnosis; pathogenesis of chronic widespread pain; early stress and trauma as a central sensitization model; FM; and psychiatric comorbidity and treatment). Available evidence confirms the relevance of considering comorbidity with psychiatric disorders in pain management. The model of FM as a central sensitization syndrome and the involvement of the patients as active participants in their pain management may help improve outcomes.

Miguel-Puga, Villafuerte, and Arias-Carrión (2017) describe psychiatric comorbidity with movement disorders, especially those due to degenerative disorders. In these conditions, the extent of degenerative process as well as the impact of medication on the brain and the stress of living with a major disorder may influence the presentation of the various different disorders. The paper offers a practical approach that can help clinicians to recognize and manage psychiatric disorders in the most frequent movement disorders.

Finally, the contribution of Amoozegar (2017) addresses epidemiology, pathophysiology, genetic and environmental factors, temporal association, treatment options, and screening issues related to the association between Migraine and Major Depressive Disorder. This comorbidity is really common, and it leads significant disability. There is evidence of bi-directional causality, but longitudinal studies and brain imaging studies are warranted to better understand the pathophysiology.

Conclusions

We believe we have illustrated, in the specific fields addressed as models, how this field requires the most advanced techniques (from brain imaging to genetic research), as well as clinical synthesis skills that can bring advanced knowledge to the specific need of the person through a user-centric approach.

Moreover, since in most of these conditions early diagnosis and screening is essential, in this context more than in other fields, it is apparent that no translational dimension (‘bench side, bedside, and community’) can be neglected.

All of this indicates a path that has to go beyond the acquired certainties, a path in which simplifications can, however, be harmful.

Disclosure statement

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the paper.