Background
Depression – a condition marked by persistently low mood and a loss of interest or pleasure in daily activities – is common among people living with MS, adding significant burden to their well-being. It is challenging to detect depression in individuals with MS, as a distinction must be made between depression as a symptom of MS and as an individual syndrome. Click here to read more about depression as a symptom of MS.
In an article recently published in Nature Reviews Neurology, psychiatrist and MS Society-funded researcher Dr. Anthony Feinstein and colleagues reviewed the current scientific literature on MS-related depression. Specifically, they focused on causes, the influence of disease course, biological and psychosocial
factors, presence of other conditions, and treatment options.
Causes
Upon evaluation of genetic data collected from people with MS, the researchers concluded that the link between genetics and depression in MS remains unclear. Advancements in imaging technology have pointed to specific structural changes in the brain that may be associated with depression, however this information provides only a piece of the larger puzzle of how and why depression commonly arises in people with MS.
The article also describes a growing body of evidence which strongly connects depression to various psychosocial factors. Studies demonstrate that factors such as helplessness, uncertainty, and high stress levels are associated with depression in people with MS, and that certain coping mechanisms can greatly help in preventing or lessening symptoms.
Influence of disease course
Clinical data report higher levels of depression in people with relapsing-remitting MS compared with progressive MS, which points to the potential involvement of inflammation in the development of depression. The authors note that some aspects of depression fluctuate over time. One study they describe - involving 132 people with relapsing-remitting MS - reported a high levels of depression after a relapse, which subsided over time. Although improvements were observed, rates of depression remained high at 6 months, suggesting that, despite remission, some people with MS may not fully recover from depression.
Co-morbidities
Studies have shown that the presence of co-morbidities may contribute to the onset and severity of depression in people with MS. Co-morbidities refer to other conditions that arise in addition to MS. For example, researchers point out that people with MS who suffer from depression may also likely be affected by fatigue. However, it is difficult to fully understand this relationship, as fatigue may occur independently or as a symptom of depression. The authors suggest that successful treatment of depression may lead to improvement in fatigue.
Anxiety and anxiety-related conditions are also highly prevalent in people with MS, and are present in almost two thirds of people with MS who suffer from depression. Like depression, anxiety is difficult to diagnose in people with MS due to overlap of symptoms. Research has shown that people with MS who are affected by depression and anxiety experience tend to engage in thoughts of self-harm and face challenges with social interaction.
Cognitive impairment is observed in over half of people with MS, and can affect memory, complex thinking, and information processing. According to researchers, depression can have a negative influence on cognition, and it is unclear whether cognitive deficits can be reversed if the depression is treated. Imaging technology enables researchers to form more definitive conclusions about the link between cognitive impairment and depression in people with MS, but further research is still required.
Treatment
People with MS who are affected by depression can seek treatment in the form of medication, cognitive behavioral therapy (CBT), and exercise. CBT is a type of therapy that involves helping individuals understand the thoughts and feelings that influence their behaviour. Some research shows that CBT can be just as effective as antidepressant medication. Work in this area is still premature, and although benefits are apparent, additional studies and clinical trials are required to make an appropriate conclusion about their effectiveness.
Comment and future directions:
According to researchers, in order to advance research and clinical care for depression in MS, two research priorities must be addressed: clearly define the biological and psychosocial nature of depression in MS, and develop a rigorous definition of depression which can be used for accurate diagnosis.
In terms of how to manage depression, It is suggested that a combination of therapies may be the most effective approach to treating depression (Read about how Dr. Neil Rector from Sunnybrook Research Institute in Toronto is combining CBT and exercise to treat depression and cognitive impairment in people with MS with a grant from the MS Society). Understanding depression in people with MS is critical to develop effective strategies that will not only address the symptoms of depression, but also those conditions linked to depression, thereby improving overall health and quality of life of people living with MS.
Source:
Feinstein A et al. The link between multiple sclerosis and depression. Nat Rev Neurol 2014 Aug 12 [Epub ahead of print].