The Relationship Between Restless Leg Syndrome and Depression

Introduction 

Mental health is one of the primary factors that determine an individual’s quality of life. Those grappling with mental health issues tend to experience diminished life quality. It is encouraging that in conjunction with the academic community, members of the mental health profession have taken solid steps to improve mental health. One of the measures that they have adopted involves conducting studies with the goal of establishing the factors responsible for poor health outcomes. However, despite the efforts of the mental health practitioners, significant knowledge gaps remain. Restless leg syndrome (RLS) and depression are some of the conditions which are not fully or clearly understood. Since they have adverse impacts on human life, these conditions demand more investment and effort which are geared toward determining their association. Preliminary research indicates that restless leg syndrome may be among the risk factors for depression. The purpose of this paper is to shed great light on the relationship between two conditions. It is hoped that the paper will confirm the finding that restless leg syndrome could lead to depression.

RLS Diagnostic Criteria 

Before exploring the association between RLS and depression, it is critical to set the stage with definitions. Jovic et al. (2018) are among the scholars who have attempted to define and identify the symptoms that accompany RLS. According to these scholars, RLS is a neurological disorder of a chronic nature which is defined by a burning impulse to move one’s legs during sleep. Essentially, Jovic and her colleagues suggest that RLS cause frustrating sleep disturbance thereby eroding one’s quality of sleep. Apart from the uncomfortable urge to move one’s legs, other symptoms that constitute the diagnostic criteria for restless leg syndrome include the fact that the individual experience relief when they move their legs and a circadian rhythm defined by peak symptoms that happen during the night or in the evening (Hening et al., 2009). It is worth noting that the mere fact that one experiences these symptoms does not necessarily mean that they have developed RLS. For diagnosis, it is required that these symptoms should be persistent (Hening et al., 2009). It is important to note that different guidelines have been developed for diagnosing RLS in children. In addition to the symptoms already stated, the pediatric diagnostic criteria also stipulate that the child should experience the sensation to move their leg during moments when they are in active or are lying down (Pichietti et al., 2013). The diagnostic criteria underscore the tremendous discomfort that sufferers of RLS endure.

Depression Diagnostic Criteria 

Guidelines have been developed to provide practitioners with insights for diagnosing depression. The Diagnostic and Statistical Manual of Mental Disorders (DSM) outlines the criteria. According to this text, some of the symptoms that accompany depression include insomnia, depressed mood, fatigue, a sense of worthlessness, indecisiveness, distress and agitation (APA, 2013). In their works, various scholars have confirmed that these adverse outcomes are symptomatic of depression. For example, Krystal (2012) identified insomnia and sleep disturbances as among the symptoms that should lead practitioners to establish that a patient has developed depression.

RLS and Depression Relationship 

Now that the definitions of depression and RLS have been offered, the discussion can proceed to examine the relationship between the two conditions. Koo et al. (2016) are some of the scholars who have committed remarkable effort to understanding this relationship. They conducted a study which involved elderly men diagnosed with RLS and depression. After examining the data, Koo and his team obtained insights that led them to conclude that RLS increases the likelihood of an individual developing depression. Other scholars have made similar conclusions. For instance, in their article, Bayard et al. (2011) note that individuals with RLS are more likely to be depressed and report symptoms linked to anxiety. This conclusion is echoed in an article by Li (2012) and a team of other researchers who observed that depression in women can be blamed on RLS. There appears to be consensus within the research community that RLS is a risk factor for depression. The findings that Koo et al. obtained will provide a foundation for this research project. Restless legs syndrome is a significant risk factor that increases the incidence of depression due to sleep disturbance and periodic limb movements during sleep with which RLS is associated.

Discussion 

In the discussion above, it has been asserted that RLS is one of the factors that are responsible for depression. To understand how the two conditions are linked, it is helpful to examine the underlying mechanism through which RLS increase one’s risk of developing depression. Cho, Kim and Lee (2017) performed a study which enabled them to establish this mechanism. In their study, they gave special focus to the sleep experiences of the participants. They observed that in addition to reporting depressive symptoms, the participants with RLS also encountered serious hardships in their quest for sleep. Furthermore, these participants complained of broken sleep and waking too early in the morning (Cho, Kim and Lee, 2017). Cho and his team conclude that sleep disturbance is the primary mechanism that links RLS and depression. This conclusion finds support in an article that Samavat (2017) authored in conjunction with three other researchers. They set out to establish the association between, RLS, insomnia and depression. Samavat and her colleagues examined cross-sectional data and noted that most of the individuals with RLS reported insomnia and depression. While they do not explicitly establish an association between sleep disturbance, depression and RLS, their discussion leads one to conclude that sleep by making it difficult for individuals to experience pleasant sleep, RLS sets the stage for depression. Saini et al. (2013) joined Samavat and her team in exploring the mediating role that sleep disturbance plays in causing depression among individuals grappling with RLS. Following a rigorous data examination process, Saini and the other researchers confirmed that sleep disturbance does indeed erode the quality of life of cancer patients receiving treatment and could be to blame for the depression that they experience. These scholars represent the views of the research community. It appears that there is agreement that sleep disturbance connects RLS to depression.

In the discussion above, some of the literature which shows how sleep disturbance links RLS to depression has been examined. For the discussion to become even clearer, it is essential to examine the relationship between sleep and mental wellbeing. It is well understood that the quality of one’s sleep is among the key factors that shape their mental wellbeing. Rusch et al. (2015) are some of the scholars who have observed that good sleep is an ingredient for positive mental health. In particular, they noted that when individuals enjoy adequate and pleasant sleep, they are less likely to report depressive symptoms. Araghi et al. (2013) reinforce the conclusion that sleep disturbances are to blame for depression. In their article, they describe a study they conducted for the purpose of determining the association between poor sleep quality and depression. They state that among the obese participants that took part in the study, sleep disturbances was to blame for the depressive symptoms that they exhibited. Since research shows that sleep disturbances impair one’s quality of life by exposing them to an elevated risk of depression, the argument that these disturbances mediate the relationship between RLS and depression is sound and supported with research evidence.

In an earlier section, the signs and symptoms that make up the diagnostic criteria for depression and RLS were identified. What was clear in this section is that the two conditions share some symptoms. For example, reduced sleep efficiency and prolonged sleep latency are some of the symptoms that are found in the diagnostic criteria for RLS and depression. In their text, Koo et al. (2016) suggest that since these conditions have common symptoms, there is a basis to conclude that RLS is among the causes of depression.

In order to establish the causal link between RLS and depression, one needs to show that the association extends beyond the mediating role that sleep disturbances play. It is also critical to ascertain how periodic limb movements that accompany RLS can lead to depression. Koo et al. (2016) established this relationship through their study. They contend that RLS causes depression by pushing individuals to suffer periodic limb movements. He is not isolated since other researchers have also cited the periodic limb movements as among the symptoms of RLS which link it to depression. Taylor-Gjevre, Gjevre and Nair (2014) appear to confirm that the periodic leg movements during sleep is the main way through which RLS causes depression. Their article focuses on how individuals with RLS report experiencing periodic leg movements which they find to be frustrating and blame for their poorer quality of life. Among the key insights that the researchers share in the article is that in addition to the movements, these individuals are also more likely to display depressive symptoms (Taylor-Gjevre, Gjevre & Nair, 2014). It is true that they do not conclude that the periodic leg movements result in depression. However, from their discussion, this is the only reasonable conclusion that one can reach. For those doubtful of the mediating role of periodic leg movements, further evidence of this role can be found in the article by Choi et al (2012). The focus of their article is RLS among individuals with leprosy. Choi and his colleagues cite previous studies which have shown that in addition to experiencing periodic leg movements, the patients with leprosy also grapple with depression. This insight serves to reinforce the assertion that the periodic leg movements function as evidence that RLS causes depression.

From the discussion above, it is evident that through periodic leg movements in sleep (PLMS) which constitute its diagnostic criteria, RLS causes depression. This discussion would not be complete without a look at recent developments in studies on PLMS and RLS. Thanks to the efforts of researchers, the genetic foundation of RLS has been established. Such genes as BTBD9 have been identified as among those that are likely to be responsible for RLS (Jimenez-Jimenez et al., 2013; Kripke et al., 2015). The relevance of the genetic roots of RLS lies in how this condition causes depression through PLMS. Hyatt Moore (2014) joined forces with a group of other scholars to determine changes in genes function as a risk factor for RLS. In the article, they note that “single nucleotide polymorphisms demonstrated to increased risk of RLS are strongly linked to PLM as well, although some loci may have more effects on one versus the other phenotype” (Moore et al., 2014, p. 1535). Essentially, Moore and his colleagues noted that changes in the BTBD9 gene can lead to the development of PLMS and RLS. They basically suggest that since the two have a common genetic cause, they must be linked. The findings by Moore and his team lend support to the argument that PLMS mediates the association between RLS and depression. In a previous section, it has already been proven that depression is the result of RLS. Since RLS and PLMS appear together from a genetic standpoint, it is reasonable to conclude that PLMS serves the same purpose as sleep disturbances which have been shown to be the mechanism through which RLS leads to depression.

The discussion above has made it clear that RLS is among the primary causes of depression. In support of this discussion, research evidence has been offered. However, the discussion would benefit immensely from more evidence. Additional proof of the causal relationship between depression and RLS can be found in the treatment approaches used for these conditions. Dopaminergic drugs are among the medications that are often administered to individuals diagnosed with RLS (Rosenstein, Rabin & Kurlan, 2015; Ulfberg, Stehlik & Mitchell, 2016). These medications function by activating dopamine receptors. The dopaminergic drugs have proven to be an effective intervention for RLS. Apart from RLS, these drugs are also used for the treatment of depression (Hori & Kunugi, 2014). In another study that they conducted, Hori and Kunugi (2012) identified pramipexole, one of the dopaminergic drugs as being effective without exposing patients to side effects. Since RLS and depression are treated using the same drugs, there is no doubt that there is a close relationship between them. The mere fact that the treatment approaches for these conditions are based on the same medications does not necessarily mean that RLS causes depression. However, combined with the evidence provided in the sections above, this fact solidifies the argument that the association between RLS and depression is of the causal variety.

This far, focus has been given to evidence which suggests that RLS is to blame for depression. In addition to being drawn from scientific studies, this evidence is credible and compelling. However, for the sake of completeness and balance, it is necessary to explore the possibility that RLS does not cause depression. The proponents of this possibility could leverage research findings which cast doubt on the accuracy and strength of the argument that depression is caused by RLS. There is some research which suggests that depression could be responsible for RLS. For example, Odabas and Uca (2018) conducted a study involving Turkish participants with the aim of determining if antidepressants cause RLS. They observed that indeed, these participants reported symptoms that are in line with the diagnostic criteria for RLS. Odabas and Uca are not isolated. Such other researchers as Semiz et al. (2016) have also asserted that the medications for treating depression could be the cause of RLS. These researchers focused their study on a group of patients being treated using antidepressants. According to their observations, these patients had a higher incidence rate of restless legs syndrome. The findings by these researchers can be interpreted to suggest that depression causes RLS. In the following discussion, this interpretation is questioned with the goal of re-establishing the validity and soundness of the original assertion that depression is the result of RLS.

It is true that there are some studies which have blamed antidepressants for the development of RLS. However, it is worth noting that these studies have not established a clear and direct connection. For example, in their article, Semiz et al. (2016) simply note that the incidence rate of RLS among patients on antidepressants was higher than the general population. They do not say that the antidepressants are a cause of the RLS. Furthermore, the studies link antidepressants, and not depression, to the RLS symptoms. Depression is a complex condition which cannot be reduced to the medications used to treat it. Therefore, since the studies do not explicitly identify depression as among the causes or risk factors for RLS, the original argument that depression is caused by RLS remains valid. However, the counter-argument provided above should challenge the research community to conduct further research. This research should seek to eliminate all doubt and make it clear that depression is not to blame for the RLS symptoms that individuals may exhibit.

Conclusion 

Significance 

The significance of this research project cannot be overstated. As has been made clear in a previous section, the project’s primary goal was to determine the nature of the relationship between RLS and depression. By focusing on this question, the project has provided insights which can enhance the delivery of effective mental health services. In particular, practitioners attending to patients with RLS and depression can develop interventions which relieve the symptoms that these patients experience. For example, since the project has shown that the two conditions often occur together, the practitioners can create medications and treatment approaches which treat the conditions simultaneously. Furthermore, the project underscores the need for practitioners to join forces with the research community for research initiatives. While the project has strived to provide clear insights, much of the conclusions are the result of conjecture. In fact, an individual may argue that these conclusions are rather artificial since they are based on assumptions and incomplete information. By partnering with researchers, mental health practitioners will shed clearer light on whether a causal relationship between RLS and depression does indeed exist. Another significance of this project lies in the fact that it expands the existing knowledge while offering fresh perspectives. During the review of literature that formed the basis of the project, it was observed that no previous studies have attempted to establish the causal association between depression and RLS. The few that came close simply focused on the common themes and issues that define the two conditions. This project is unique in that it attempts to show that depression results from RLS.

Limitations 

As is the case with other studies, this project suffers various limitations and shortcomings which erode its strength. The main limitation is that the project is based primarily on a study which involved participants who do not necessarily reflect the general population. As noted in the introduction section, the study by Koo et al. would provide the framework within which this project would be conducted. For their study, Koo and his team worked with a group of elderly patients. While the observations that they made are insightful, questions can be raised about whether these observations can be applied to the general population. It could be that women or young adults report experiences that differ significantly from those of the elderly participants who took part in the study by Koo et al. Therefore, since it is founded on a study with limited application, practitioners incorporating the insights shared in this project into their practices should proceed with caution. While it suffers limitations, this project remains authoritative, credible and reliable. It is the result of extensive and rigorous literature review.

Future Research Directions 

Sleep disturbances and PLMS were given immense focus in this project. These factors were selected because Koo and his colleagues identified them as the primary mechanisms that RLS relies on to cause depression. However, it should be noted that there is likelihood that other factors beyond these two explain the relationship between depression and RLS. The research community needs to investigate how these other factors mediate the link between RLS and depression. For example, it could be that the physical discomfort that accompanies RLS is how this condition causes depression. This possibility underscores the need for further research. Whereas it is true that it does not answer all questions regarding the association between RLS and depression, this research project presents value and plays a critical role in enriching existing knowledge.

Summary and Conclusion 

RLS and depression remain some of the conditions for which individuals seek help. Practitioners have been unable to effectively deliver services because they do not fully understand how the two conditions are related. Thanks to the efforts of the research community, the association between RLS and depression is becoming clearer. There appears to be consensus that RLS causes depression. To support the argument that the link between the conditions is causal, researchers cite the fact that the conditions share symptoms and that they respond to the same treatments. However, before concluding that RLS is responsible for depression, it is worth noting that there are questions that remain unanswered. Among these questions concerns the fact that medication for depression has been shown to trigger RLS symptoms. It is clear that conclusive answers are yet to be gained. In order to find these answers, more research is required. There is a need for the research community to dedicate more effort to understanding the exact nature of the relationship between RLS and depression.

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