The discussion surrounding mental health has broadened in the last few years with more becoming more aware of the issues and how to prevent them. It’s reported that 1 in 6 people in England experience common mental health problems; students are all too familiar with the mental toll of exams, assignments, and the struggle of a balanced lifestyle. In these cases, it’s advised to eat well, exercise, and most importantly sleep well, so the use of sleep deprivation, or “wake therapy”, seems paradoxical.
Even with the availability of many new drugs and therapies to help those cope with mental illness, these may prove ineffective. In these cases neuroscientists, psychiatrists, and therapists seek for innovative ways to fill in the gap where antidepressants and behavioural therapies fail. Depression linked to bipolar disorder is one such illness that antidepressants either cannot aid or they may quickly become ineffective, and so other methods are needed to provide the “antidepressant effect”. It just so happens that wake therapy can provide that effect.
First recorded in experiments by Burkhard Pflug in 1976, single-night sleep deprivation on 124 depressive patients yielded therapeutic results. In 16 of 45 patients with clinical depression, the single night was reportedly enough to alleviate their symptoms. Similar effectiveness was reported in those with bipolar disorder, while the opposite effect was seen in schizophrenic patients – so like all treatments, wake therapy has its limits.
In recent practice, wake therapy is used in conjunction with lithium (a common drug used to treat bipolar disorder) to prolong the effects of the sleep deprivation, proving effective for 65% of psychiatrist Francesco Benedetti’s patients. Finding that even short naps could reduce the effectiveness of the treatment, Benedetti found bright lights used to keep pilots awake could do the same to patients and thus extend the effects of wake therapy. He called this method “triple chronotherapy”. In 1996, Benedetti introduced the therapy into San Raffaele Hospital, and since then has treated around 1000 patients with bipolar depression who did not respond to antidepressants or become tolerant to them. The most recent data showed over 70% of patients responded to triple chronotherapy in the first week and 55% had a sustained response.
But why does this work? The answer lies in your circadian rhythm – the regular time cycle controlled by the hypothalamus in your brain and vital in regulating your sleep-wake cycle among other functions.
Light is a powerful external indicator for a human’s sleep/wake cycle so the bright light method is effective because the retinas of your eyes picks up the brightness and send signals to the hypothalamus. The hypothalamus equates this brightness to the day time and signals to keep you awake, specifically by reducing the sleep hormone “melatonin” in your body. Circadian processes can directly affect mood in healthy people therefore in cases of depression, the shift can exacerbate the existing condition. In fact, the most reported disturbance in patients with depression is due to the sleep-wake cycle, as 90% of sufferers complain of difficulty falling asleep, staying asleep, and waking up.
The link between your circadian rhythm, wake therapy, and depression isn’t yet clear but suggestions have been proposed. For example, the “Phase-Shift” hypothesis is a result from a
delay or advance in signalling from the hypothalamus (central regulator) and can alter your sleep cycle negatively compared to the other cycles in your body that contribute to the circadian rhythm. The cycles can be re-synchronised using wake therapy and bright lights to control when the melatonin (sleep hormone) is released.
For severely depressed patients, the disruption of the sleep/wake cycle is significantly greater. Normalising the cycles is thought to be the key to improving the symptoms, and with more research it could be found that this is the case. If so, the link between depressive symptoms and the disruption of the circadian rhythm can be substantiated. It should be stressed that this method is useful for those with very severe forms of depressions, using wake therapy with milder depression and other conditions may have the opposite effect and worsen symptoms.
The seemingly contradictory nature of wake therapy is an interesting observation of how greatly conditions like depression can affect you by causing a ripple within your internal systems. As research continues we can gain a better understanding of the mechanisms that govern the effectiveness of wake therapy and take a big step forward in understanding treatments for complex mental illnesses.