BPD Depression and Biological Rhythms

Bipolar disorder is characterized by extended periods of (generally) cycling high and low states. The  high state, called mania, is marked by high energy, reckless behavior, racing thoughts, feelings of grandeur or increased self confidence, as well as a reduced need for sleep. The low state, or depression, is characterized by sluggishness, feelings of hopelessness, loss of interest, etc., but also either increased need for sleep or insomnia. For both aspects of bipolar disorder, sleep is a major factor and is majorly affected by the disorder.

In a recent study, a group of scientists investigated the association between depression and  biological rhythms in the functioning of bipolar disorder sufferers. Biological rhythms are the natural patterns of functioning that our bodies follow. For example, ultradian rhythms occur more than once a day, like patters of hunger, and circadian rhythms occur over a period of about 24 hours, such as our daily sleep schedules. In accordance with the symptoms of bipolar disorder, the scientists in this study hypothesized that more severe depression would equate more disruption in biological rhythms. 

In order to test these disruptions, an interview administered questionnaire was used to asses disruptions in sleep, eating patterns, social rhythms, and general activity, under the protocol of the Biological Rhythms Assessment in Neuropsychiatry (BRAIN). Patients were first evaluated for manic and depressive symptoms with the Young Mania Rating Scale, and those afflicted with depression were sorted into three groups based on severity of symptoms: remission, subsyndromal, and depressed. The total of 260 bipolar patients, as well as 191 healthy patients, all from Spain, Canada and Brazil, were then interviewed. Various levels of statistical analysis were performed to confirm significance of results and accurate comparison of the four groups. As predicted, depressed patients had the greatest disturbance in biological rhythms, followed by patients with subsyndromal symptoms, patients in remission, and finally, the healthy control patients. 

Overall, the results of this study were nothing short of expected. The DSM-5 criteria for diagnosing bipolar disorder specifically outlines sleep disturbances as indicators of the disorder. Additionally, the only methods of testing used were interview based, nothing biological. I think it would have been interesting to see the results of testing various hormonal levels in the body that pertain to biological rhythms, and a comparison of the levels or times of day where hormones were present in depressive bipolar disorder patients to those in healthy control patients. As only interviews were given, it makes sense that the patients first diagnosed with bipolar disorder would then self report having the symptoms of bipolar disorder (disrupted sleep, eating patters, activity, etc.). 

This article first grabbed my attention because I have often noticed the disrupted sleep patterns in a close friend of mine who has bipolar disorder. Getting too little sleep for instance makes it more likely that a manic episode will be triggered, and part of his treatment involves maintaining a highly regulated sleep schedule. I was hoping that this article might give me more insight into how bipolar disorder works biologically, but while the study was not uninteresting, it's results were not at all surprising or new in their idea. 

Source (VT Libraries): http://su8bj7jh4j.search.serialssolutions.com.ezproxy.lib.vt.edu/?sid=EBSCO:Academic%20Search%20Complete&genre=article&title=Acta%20Psychiatrica%20Scandinavica&atitle=The%20association%20between%20biological%20rhythms%2C%20depression%2C%20and%20functioning%20in%20bipolar%20disorder%3A%20a%20large%20multi-center%20study.&author=Pinho%2C%20M.&authors=Pinho%2C%20M.%3BSehmbi%2C%20M.%3BCudney%2C%20L.%20E.%3BKauer-Sant%27anna%2C%20M.%3BMagalhães%2C%20P.%20V.%3BReinares%2C%20M.%3BBonn%C3%ADn%2C%20C.%20M.%3BSassi%2C%20R.%20B.%3BKapczinski%2C%20F.%3BColom%2C%20F.%3BVieta%2C%20E.%3BFrey%2C%20B.%20N.%3BRosa%2C%20A.%20R&date=20160201&volume=133&issue=2&spage=102&issn=0001690X