Continuous Positive Airway Pressure as Depression Treatment - Research Paper Example

? Can the Use of Continuous Positive Airway Pressure (CPAP) be an Effective Treatment for Depression? S. XX Both I and members of my family have suffered from some sort of depression at one time or another. My mother was diagnosed with both depression and obstructive sleep apnea (OSA) six months ago. We have all noticed a huge improvement in her attitude and depression since she started using a CPAP (Continuous Positive Airway Pressure) machine. She says that the diagnosis of OSA and the subsequent treatment with the CPAP have greatly improved her depression. She is now slowly being taken off her antidepressants. Her experience sparked my interest in whether CPAP machines can be successfully used to treat depression. The symptoms of OSA and depression are similar in many respects, posing a challenge for doctors who wonder whether they have mistakenly diagnosed a patient as having depression when he or she actually has OSA. Researchers have attempted through a variety of studies to understand the relationship OSA and depression (Means, et al 2003). The following three literature reviews look at the connection between OSA and depression and present the hypothesis that CPAP machines, which alleviate symptoms of OSA, can also be used to alleviate symptoms of depression in OSA patients. In their research, Means, Lichstein, Edinger, Taylor, Durrence, Husain, Aguillard, and Radtke (2003) observed that many studies had found that up to 63% of people who suffer from untreated obstructive sleep apnea (OSA) also suffered from depression. They noted that because there were also studies that did not find a relationship between OSA and depression, researchers would need to conduct a study to clarify the link between the two by first treating the OSA and then observing any corresponding changes in depression levels. Their study did indeed show that depression is alleviated when OSA is successfully treated using a continuous positive airway pressure (CPAP) machine. However, the question remained as to whether emotional symptoms of depression were lifted because the stress of OSA had finally been relieved, or whether the physical symptoms of OSA, which researchers have found to be much like those of depression, had led to improper diagnoses of depression in the first place. Researchers determined that an OSA study that separated the emotional and physical symptoms of depression would better show whether CPAP treatment truly alleviates depression in OSA patients. Unlike studies conducted by others, Means’ team incorporated the Beck Depression Inventory (BDI), which separates the two categories of depression symptoms, so that they could determine whether treatment improved both categories of symptoms or just the physical ones. They used patients who were not diagnosed with depression already. The BDI showed that OSA sufferers showed marked levels of mild to moderate depression compared to the control groups. In fact, half of the patients showed increased levels of depression based on the BDI, mainly emotional (also known as affective/cognitive). Means’ team knew that studies already show that the more time patients spend using the CPAP machine, the better their mood (Means et al, 2003). They therefore predicted that their study would show improvements in the emotional symptoms of depression in patients who regularly used the CPAP. At the end of their study there were fewer than 50 patients from whom data could be drawn. While data regarding the amount of time the CPAP was used could be drawn from over half of the remaining units, data from the remaining patients came from self-reporting. Researchers found that 51% of the participants used the CPAP regularly, while 49% did not (Means et al, 2003). They discovered that three months of CPAP use led to small improvements in BDI levels, and these improvements occurred in equal amounts for both the emotional and physical categories of symptoms regardless of the amount of time the CPAP was used. Because 42% of study participants had shown undiagnosed depression, Means’ team was now convinced that OSA and depression are connected (Means, et al, 2003). The team determined that symptoms associated with OSA may actually be depression, and that both emotional and physical symptoms are present in these patients. Still, the researchers acknowledge that more research is needed to show that OSA and depression are linked, and further research would be needed to show how well CPAP machines actually affect depression. A couple of years later, Schwartz, Kohler and Karatinos published a study on the usefulness of CPAP machines in alleviating symptoms of depression in OSA patients. As with Means et al (2003) they wondered if OSA symptoms might be mistakenly diagnosed as depression, or whether OSA actually causes depression. They wanted to know whether CPAP could relieve the symptoms regardless of their origin. Patients were eligible for their study whether or not they had been treated for depression, but only patients who used the CPAP machine every night were used for the final report. The findings of Schwartz et al (2005) were highly similar to those of Means’ 2003 study, despite the fact that the two studies were designed differently. Schwartz’s team found that CPAP machines can improve symptoms of depression in OSA patients. Schwartz et al. (2005) acknowledged that there were weaknesses in their research. Unlike Means’ team, they collected only subjective reports from patients about their CPAP use rather than downloading data from the machines. The team feels that patients would probably overestimate their use of the CPAP than underestimate, however, which would even more strongly support their findings that CPAP machines can alleviate depressive symptoms. Other weaknesses, however, could affect the reliability of the study. For example, they acknowledge that there could have been a placebo affect whereby patients using a CPAP machine would expect to feel better, thereby subconsciously influencing themselves to actually believe they feel better (Schwartz, Kohler & Karatinos, 2005). Selection bias is another possible problem, and their use of the BDI raised doubts because it was not developed to detect changes in depression levels (Schwartz et al, 2005). While Schwartz et al (2005) found that CPAP machines improved depression in OSA patients, the reasons for this remained unclear to them. Still, the team was confident enough in their findings to suggest that doctors check their OSA patients for depression, and to look for evidence of OSA in patients reporting depression. For both, they suggested that doctors consider CPAP treatment. Schwartz and Kartinos (2007) moved research in the field forward with the claim that they found long term success in the treatment of depression in OSA patients who use CPAP machines. Their study focused on 50 patients from Schwartz’ previous study; these were the ones who responded first to a request for follow-up research. Of these, only those who reported using the CPAP regularly and had not had surgical treatment of OSA were studied. This left 39 subjects. Although 61 patients did not respond to requests for follow up, the researchers determined that they were not significantly different from those who did participate (Schwartz & Kartinos, 2007). The follow up study was particularly useful because the researchers sought patients with a specific, reversible diagnosis who confirmed use of the CPAP machine and had measureable improvements specifically in the area of depression. Other studies had not used as many patients, or had focused on a general sense of well-being rather than on measureable levels of depression. Schwartz’s and Kartinos’ research still presented some weaknesses, such as selection bias and the lack of full participation from all of the patients of the previous study. This means they could not state with certainty that long-terms maintenance of lower BDI scores would apply to a larger group (Schwartz & Kartinos, 2007). They also acknowledge criticism of the BDI, which does not address all of the symptoms of depression. Still, the researchers say the evidence supports their claim that when OSA patients use a CPAP machine long term, both doctors should expect some improvement in the depression experienced by many of these patients. Together, these three studies affirm that Continuous Positive Airway Pressure machines are an effective treatment for depression in patients who suffer from obstructive sleep apnea. OSA patients who use CPAP machines regularly were found to have significantly measureable improvements in their symptoms of depression. All three studies have been criticized for various weaknesses in methodology, but the researchers strongly believe that these weaknesses do not invalidate their findings. There is still not enough data to explain exactly how depression and OSA are linked, therefore more research needs to be done. Still, the fact that three studies using different methodologies confirm the benefits of the CPAP is a strong finding supporting the medical recommendation of the CPAP machine as a viable treatment for depression in people with OSA. References Means, M.K., Lichstein, K.L., Edinger, J.D., Taylor, D.J., Durrence, H., Husain, A.M., Aguillard, R.N., & Radtke, R.A. (2003). Changes in Depressive Symptoms after Continuous Positive Airway Pressure Treatment for Obstructive Sleep Apnea. Sleep and Breathing, 7(1), 31-42. Schwartz, D.J., & Karatinos, G. (2007). For Individuals with Obstructive Sleep Apnea, Institution of CPAP therapy is Associated with an Amelioration of Symptoms of Depression which is Sustained Long Term. Journal of Clinical Sleep Medicine, 3(6). 631-635. Schwartz, D.J., Kohler, W. C. & Karatinos, G. (2005). Symptoms of Depression in Individuals With Obstructive Sleep Apnea May Be Amenable to Treatment with Continuous Positive Airway Pressure. Chest, 128(3), 1304-1309. Doi:10.1378/chest.128.3.1304 Glossary BDI- Beck Depression Inventory, used in the studies mentioned above to measure levels of emotional depression on a scale from one to three. CPAP- a portable machine that uses a continuous flow of air to keep breathing passages open while a person sleeps. OSA- Obstructive sleep apnea. A condition whereby a person’s airway is periodically blocked, causing decreased oxygen levels and pauses in breathing. Read More