Those in the medical field, as well as anybody who has ever been prescribed an antidepressant, are well aware that finding the medication that is going to work best for a particular patient is a hit-or-miss process that can take several months to complete. Every patient is different and will have a different response to a specific medication or class of medication, and because each requires a full four to six weeks in order to become fully incorporated and effective in the system, the process is time consuming and frustrating. Now a physician has created a method that he believes is predictive of whether the most popular class of antidepressants will work on a specific patient, and his methodology revolves around the way that the patient sleeps. Dr. W. Vaughn McCall is the chairman of the Department of Psychiatry and Health Behavior at the Medical College of Georgia at Georgia Regents University in Augusta, Georgia. Dr. McCall has just completed a research project in which he asked patients to wear simple wristbands that monitor and record their level of activity through a 24-hour period, including the way that they sleep. He has concluded that it is an inexpensive and safe way to determine which patients are most likely to respond best to Prozac and other drugs in the selective serotonin reuptake inhibitor, or SSRI, class of drugs. SSRIs are among the most popular antidepressants on the market today. They are both effective and have the advantage of eliminating many of the negative side effects that are part and parcel of earlier types of drugs, but that does not mean that they work for everybody. Dr. McCall says that physicians often end up going through several different medications before they hit on the one that will work best for a patient, and each drug needs to be taken for several weeks before its effectiveness an be gauged. “You only hit a home run first at bat about one third of the time; two thirds of the time you have failed, struck out,” he says. Dr. McCall is a widely regarded expert in the areas of depression, suicide and insomnia. His study, which concludes that those who are classified as night owls are most likely to respond well to SSRIs, was published in the Journal of Psychiatric Research. Though Dr. McCall’s research included only 58 patients and he admits that the findings are only preliminary, he is still optimistic about their successful application. “What our findings suggest is that night owls, the group most likely to be depressed, also look like the patients who are most likely to respond. The larks are more likely to need two drugs.” In referring to night owls and larks, McCall is using terms that are familiar to sleep researchers, and which refer to each individual’s chronotype – the time that they most regularly and most comfortably fall asleep each night and wake up each morning. Recent research has shown that the difference is more than just a preference or personality type, and that larks and night owls actually have different brain structures, and now McCall believes that the difference may also lead to a variation in the way that they respond to different drugs. The reasoning behind his theory makes good sense. One of the mechanisms of SSRIs is to shift the brain’s rest time to the middle of the night, and that is something that would not be as effective for those who are early risers and go to bed early as well. For the lark group, drugs that target dopamine and provide stimulation during low activity time may be more successful and coincide best with their schedules. “We all tend to be morning people or not, and environmental factors, such as work schedules, can also push us in one direction or another,” he says. These factors include such variables as whether we’re exposed to outdoor light or electronic light from our tablets and smart phones, both of which have been shown to impact the circadian rhythm and what time a person begins to feel drowsy. Though most people are familiar with the term night owl or lark, there is little hard information regarding how represented each group is within the population. The patients who participated in McCall’s study were evenly split, and the later a night owl tended to go to sleep, the more effective the SSRI was in treating their depression. The patient at the farthest end of the scale did not go to sleep until five o’clock in the morning. The use of a motion-tracking monitor provides an inexpensive method of identifying patients who may potentially benefit where there is currently no other test. Blood work will not provide an answer, so doctors are stuck with a trial-and-error method. McCall says that he tries to begin with the least expensive SSRI but warns his patients that they may need to go through several different attempts before they find the drug that works best for them, and this can be particularly frustrating for those who are suffering from severe depression. Patients with major depressive order are impacted by their illness to a degree where they feel that the quality of their life is affected, and they may end up over or under sleeping, losing interest in eating or having sex, over eating, and thinking of ending their lives. “You are treating patients both to relieve their misery and to improve their function, but our treatments are unreliable. We go through a trial-and-error process and people suffer for a long time,” McCall says. The determination that a patient’s pattern of rest and activity may prove to be a predictor is exciting news for those trying to help. McCall says, “It gives us a place to start,” and is seeking federal funding to expand his research.