Copyright 2009 American Medical Association. All Rights Reserved. Applicable FARS/DFARS Restrictions Apply to Government Use.
Licht et al1 discuss a relationship between depression and heart rate variability in their sample, which was also studied for the presence of other health-related variables, including heart disease and chronic medical conditions. Not specifically mentioned in their report is the presence of sleep-related breathing disorders (including sleep apnea) as a potential confounder, which is surprising given the evidence that exists linking these conditions to both diminished heart rate variability2 and depression.3
The multiple overnight arousals that occur in sleep apnea result in a number of physiologic insults, including cardiac effects due to sympathetic activation as well as affective dysfunction related to nonrestorative sleep punctuated by apneic periods. Also, there are several diagnostic overlaps between the excessive daytime sleepiness that results from untreated sleep apnea and the symptoms of major depressive disorder, including mood alteration, diminished functionality, fatigue, sleep disturbance, and cognitive changes, all suggesting the possibility that an unaddressed sleep disorder may have had some bearing on covariance in this sample.
Subjects were evaluated for body mass index at the time of study, and while elevated body mass index values do correlate with the likelihood of obstructive sleep apnea being present, the syndrome does occur in individuals of normal weight.4 While the presence of heart disease in subjects was acknowledged, the specific diagnoses mentioned (coronary disease, cardiac arrhythmia, angina pectoris, heart failure, and myocardial infarction) could themselves be conceptualized as sequelae of obstructive sleep apnea.
It is possible that sleep-related breathing disorders were addressed in the analysis; however, the absence of their mention in the publication leads the reader to ponder effects of this potential confounding variable.
Correspondence: Dr Kierlin, Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, 760 Westwood Plaza, Los Angeles, CA 90024 (lkierlin@mednet.ucla.edu).
Financial Disclosure: None reported.
Country-Specific Mortality and Growth Failure in Infancy and Yound Children and Association With Material Stature
Use interactive graphics and maps to view and sort country-specific infant and early dhildhood mortality and growth failure data and their association with maternal
Instructions
Comments are moderated and will appear on the site at the discretion of the Archives of General Psychiatry editors. Comments should not exceed 500 words of text and 10 references.
Do not submit personal medical questions or information that could identify a specific patient, questions about a particular case, or general inquiries to an author. Only content that has not been published, posted, or submitted elsewhere should be submitted. By submitting this Comment, you and any coauthors transfer copyright to the journal if your Comment is posted.
* = Required Field
Disclosure of Any Conflicts of Interest* Indicate all relevant conflicts of interest of each author below, including all relevant financial interests, activities, and relationships within the past 3 years including, but not limited to, employment, affiliation, grants or funding, consultancies, honoraria or payment, speakers’ bureaus, stock ownership or options, expert testimony, royalties, donation of medical equipment, or patents planned, pending, or issued. If all authors have none, check "No potential conflicts or relevant financial interests" in the box below. Please also indicate any funding received in support of this work. The information will be posted with your response.
Register and get free email Table of Contents alerts, saved searches, PowerPoint downloads, CME quizzes, and more
Subscribe for full-text access to content from 1998 forward and a host of useful features
Activate your current subscription (AMA members and current subscribers)
Some tools below are only available to our subscribers or users with an online account.
Download citation file:
Customize your page view by dragging & repositioning the boxes below.
and access these and other features:
Register Now
Enter your username and email address. We'll send you a reminder to the email address on record.
Athens and Shibboleth are access management services that provide single sign-on to protected resources. They replace the multiple user names and passwords necessary to access subscription-based content with a single user name and password that can be entered once per session. It operates independently of a user's location or IP address. If your institution uses Athens or Shibboleth authentication, please contact your site administrator to receive your user name and password.