By Holly A. Swartz, MD, author of The Social Rhythm Therapy Workbook for Bipolar Disorder
Social rhythms are interpersonal or socially regulated factors that affect circadian rhythms. Social rhythms are both a product of circadian rhythms (eating meals with friends when you feel hungry) and a driver of circadian rhythms (getting up at the same time every day because you have to go to your job). If you have bipolar disorder, having regular social rhythms can help improve your mood by stabilizing your circadian rhythms. In this chapter, we’ll explore relationships among social rhythms, circadian rhythms, and mood.
What are zeitgebers? Body clocks depend on external cues to keep circadian rhythms running on a 24-hour cycle. These external inputs are known as zeitgebers. From the German word for “timekeeper,” zeitgebers are rhythmically occurring environmental factors that entrain body clocks and circadian rhythms. You can think of zeitgebers as environmental anchors or signposts. Because of evolution and biology, the rising and setting of the sun is the most powerful signpost in our environment. Other important signposts include changing seasons, temperature, and food availability.
What is a social zeitgeber? When geophysical cues such as light are less pronounced, regular social interactions known as social zeitgebers or social signposts entrain the circadian system by acting as surrogate anchors or pacemakers. Examples of social signposts include work, meals, and leisure activities. Social signposts, therefore, are social factors that help our bodies keep track of time. Here are some examples of social signposts helping to entrain body clocks:
· Tim’s dog Bruno always wakens him at 6:30 a.m. to let him out. If Tim doesn’t get up, Bruno whines and makes a mess in the house. Bruno is a social zeitgeber or social anchor for Tim because he helps Tim get up at the same time every morning.
· Even though they live far away from each other, Zenia calls her mother every day around dinner time. If she forgets to call, her mother gives Zenia a really hard time. Even though Zenia sometimes resents having to call her mother, she almost never forgets that phone call. Zenia’s mother is a social zeitgeber for Zenia. Her phone call to her mother is a social signpost because it helps to mark Zenia’s transition from daytime to evening.
· Jeff ’s barista shift at a coffee shop starts at 7 a.m. To get to work on time, Jeff awakens at 6 a.m. Jeff’s work obligation acts as a social anchor for Jeff.
What are social rhythms? Do you get up when the sun rises and go to sleep when the sun sets? Probably not! In preindustrial, agricultural societies, circadian clocks were entrained almost exclusively by the rising and setting of the sun; in the modern world, however, we’re no longer tightly bound to the natural environment. Consequently, our biologic clocks are at least partially entrained by recurrent social zeitgebers. These repeating lifestyle or interpersonal routines that affect the biologic clock are known as social rhythms.
How do social rhythms affect mood? Regular social rhythms help to keep the body clock running smoothly. By doing the same thing at the same time every day, social rhythms remind the body clock when it is. Social rhythms help body clocks to stay on their roughly 24-hour cycle, thereby stabilizing circadian rhythms. If you have bipolar disorder, stable social rhythms will help your mood become or stay stable. The converse is also true, however: disrupted or irregular social rhythms may destabilize your circadian rhythms and make your mood worse. Therefore, the goal of SRT is to help you stabilize your social rhythms to stabilize your mood.
Social rhythms and bipolar disorder. Research has found that social stresses contribute to the onset of mood episodes and worsening of symptoms in bipolar disorder. However, social stresses related to destabilized social routines or rhythms appear to be especially potent risk factors for worse outcomes in bipolar disorder. Examples of social rhythm disruptions that put you at risk for mood symptoms include spending the night in the emergency room, staying up all night to study for an exam, or going on vacation. Disrupted or irregular social rhythms may lead to or be the result of a bipolar mood episode.48 By contrast, periods of mood stability are associated with very regular social rhythms. For instance, going to bed at the same time every day, eating meals at regular times, and exercising at the same time every day may help your mood. Having stable moods may also make it easier to stay on a regular schedule.
Holly A. Swartz, MD, is professor of psychiatry at the University of Pittsburgh School of Medicine, director of the Center for Advanced Psychotherapy, and an internationally recognized expert in psychosocial interventions for bipolar disorder. She is actively engaged in teaching, research, mentoring, and patient care. Swartz has held elected leadership positions for national and international professional organizations, including serving as president of the International Society of Interpersonal Psychotherapy, president of the International Society for Bipolar Disorders, and treasurer of the American Society of Clinical Psychopharmacology. She is author of more than one hundred publications, coeditor of Bipolar II Disorder, and editor in chief of the American Journal of Psychotherapy.