One of the oddest things to write about in sleep medicine is the downside of sleeping better. Strange though it may be, there are several instances where an individual may sleep markedly better than before treatment, often in the example of someone using PAP therapy to treat a moderate to severe OSA/UARS condition, and the resultant improvement in energy may lead to assorted new issues.
A well described phenomenon in this realm unexpected adversity is the unmasking of a bipolar or hypomanic patient, including those with or without prior recognition of the pre-existing condition. At least three case reports have documented this occurrence. (1-3) No question there is value in helping a patient recognize an underlying mental health disorder, but it is equally fair to say that the OSA disorder was in fact protecting the individual from the potential harm and danger from what often arises from mania.
In two of the cases with extensive descriptions of what transpired following PAP treatment, numerous disturbing behaviors were observed including worsening of anxiety, physical aggression, racing thoughts, insomnia, pressured speech, reckless driving, psychomotor agitation, grandiose delusions.(1)
Along the lines of increased energy, but not necessarily related to a manic episode, I dealt with a male patient who initiated PAP therapy and rapidly developed a markedly increased libido, leading to a state of hypersexuality, which triggered a series of adulterous encounters and eventually led to a divorce from his wife.
Some of the less serious but still disturbing or annoying behaviors are the unmasking of an irritable personality in someone who was previously so fatigued, he or she was always too tired to display their nettlesome disposition. One would hope the renewal of energy would lead to greater awareness in an individual, but the extra fuel in the tank for some people actually pushes them to push harder in their daily activities, sometimes pushing against other people in irritating if not abusive ways.
Perhaps the worst of all effects of sleeping better are those associated with weight gain. As the speculation goes, a person with new energy either increases their physical activity level, which then increases their appetite or the increased energy itself directly increases appetite. Although there is no definitive proof on this concept, most sleep specialists now recognize that obese patients treated for sleep apnea either gain or lose weight or show no change in weight. These observations are so common that sleep doctors no longer tell their patients to anticipate weight loss when initiating PAP therapy, which years ago was a very frequent comment offered to OSA/UARS patients as an incentive to start treatment. Indeed, a recent meta-analysis supported the view that weight gain following CPAP therapy is much more common than previously realized. (4) Another study suggested that very obese patients were at special risk for continuing to gain weight while on CPAP.(5) Doing a Medline search, you will notice that several more research studies and commentaries have been published on this topic just in the past few years, many of them pointing out this adverse effect to PAP therapy.
In my own clinical experience, I have not discovered a particular phenotype (certain characteristics of a patient where the pattern may predict another behavior) that would indicate a greater likelihood for weight gain or loss upon initiating PAP. More obvious phenotypes might turn out to be patients with depression who already struggle with weight issues as well as being subjected to antidepressants that predispose toward weight gain. Overall, research in this area remains limited despite the recent influx of publications on the topic. Nevertheless, it is unfortunate but true that a fair number of sleep apnea patients gain weight after PAP use, which is a very frustrating experience for them.
The last and one of more idiosyncratic responses to sleeping better is how it may spoil an individual into no longer being able to tolerate sleeping poorly after having experienced the joy of a good night’s sleep. The most obvious scenario occurs when an individual develops a cold and cannot use PAP therapy or an individual travels and forgets to bring his or her leg jerk medication. Even among those who use sedatives and truly receive an excellent response for the insomnia and in their sleep quality also develop this “spoiling” effect, which in other terminology could be called dependency. To be sure, a PAP user is in fact dependent on the device as are restless legs/leg jerks patients dependent on their meds.
The psychological term “distress intolerance” is used to describe how people react to the loss of a stable equilibrium in their health or in this specific instance their sleep. When the equilibrium or balance changes and moves in the direction of worse health or sleep, the latter measured either in poorer sleep quality or more overt disruption to sleep continuity (insomnia), any person will react with some degree of frustration or concern. But, once you have raised your level of equilibrium to a much higher level of sleep quality and fewer bouts of insomnia, the falling back to the old sleep pattern feels like a much further drop off in quality or continuity of sleep. A sizeable number of patients on PAP therapy, or leg jerk meds, or sedatives will unequivocally report that they will not sleep without their treatment in place.
The distress intolerance is so great without the treatment, the patient will also develop further anxiety about the whole experience that further worsens sleep. Although we would never compare the magnitude of this distressing experience to a cancer patient who was in remission for several years and then suddenly learned the cancer had returned, the operating principles are similar in the circumstances in patients who cannot use their treatments for months due to extenuating circumstances (e.g side-effects to drugs or facial or oral surgery preventing use of PAP).
While most of us appreciate that a great deal of good ensues from sleep therapies, there are some patients who suffer from these issues, and it is not unusual for some individual to cease treatment altogether. Over time, many may be brought back into treatment, but their motivation is more likely to rise to the occasion when they are more certain the side-effects, as feasible, can be prevented.