Dreams – repressed desires or warning signals for disease?

This is an article I wrote for the London Student

Our fascination with dreams dates back centuries. Ancient cultures such as the Egyptians and Greeks even had dedicated gods of dreams. In the early 20th century, the founding father of psychoanalysis, Sigmund Freud, suggested that dreams are a manifestation of our most secret and repressed desires; and instead of living them in real life, we act them out in our dreams. Recent research has shown, however, that there might be more to dreams than just unfulfilled needs. In fact, dreams could be an indicator and predictor of certain diseases.

Nightmares, for example, could be a sign of heart conditions, migraine, sleep deprivation or a side effect of beta-blockers. Many dreams could be an indication for either being too hot or cold during the night, hormones, chronic pain, or coming off antidepressants.

Too much alcohol, an infection, the menopause or anti-malaria pills could cause memorable or bizarre dreams. A fatty meal, too much weight, stress or depression could give you dreams that wake you early; and sexual dreams do not necessarily represent anything about a person’s sex life, but could actually be triggered by creativity. Many pensioners reported having increased sexual dreams, which could be caused by taking up new hobbies during retirement.

Bashing about in your dreams, or dreams of attacks or wild animals, could be an early warning sign for Alzheimer’s or Parkinson disease. These dreams can be one of the first recognisable symptoms and can appear even a decade before the actual onset of the disease.

Alzheimer’s is a neurodegenerative disease, in which insoluble mutated protein (amyloid-β)clumps called plaques accumulate in the spaces between nerve cells. Protein tangles can even build up in nerve cells, thus hindering nerve cells to function properly.

Sleep disturbances, and in particular increased daytime sleepiness, could be an early sign of Alzheimer’s, which could be caused by the protein plaques. Researchers discovered that in mice the plaque concentration peaked during wake times, but fell when mice were asleep. Depriving mice of sleep increased the protein concentration dramatically. Once the plaques were removed, their sleep pattern went back to normal. Daily fluctuations in the concentration of the mutated protein were also found in humans.

It remains unclear whether the sleep disturbances lead to Alzheimer’s, or if they are caused by it, but it is suspected that they might reinforce each other. “Abnormal sleep in mid-life might cause protein aggregation that starts the disease off,” Holtzman tells Nature “, and the damage it causes may further disrupt sleep.” “Once we saw that amyloid-β was going up and down with the sleep–wake cycle, the implications began to unfold,” says Holtzman. These findings suggested that sleep disturbances might actually precipitate plaque formation. And if a sleep deficit could increase the concentration of soluble amyloid-β, says Holtzman, then sleep abnormalities in earlier life may predispose people to Alzheimer’s.”

During an 8-hour sleep period, the brain goes through different stages of electric activity in repeating cycles that change about every 90 minutes. We spend about 20-25% of our sleep in the REM phase (rapid eye movement), which is often associated with dreaming. During sleep, information is downloaded from one brain region to another, so sleep is a crucial time for learning and memory consolidation. It is now known that memory processing and even dreaming are not confined to the REM phase. It might help us, however, to deal with emotional processing of events that happened during the day. Research has shown that the slow wave sleep phase is very important for memory consolidation and learning, but it becomes shorter in the ageing brain. It seems that an ageing or deteriorating brain, bad memory and bad sleep are somehow connected.

Many factors can influence the sleeping and dreaming pattern, we can control some, but others we cannot. Despite a lot progress in research, our understanding of the brain and its functions remain partly unclear. Until we have resolved the mystery of why we dream, what our dreams mean, dreaming will certainly remain an enigma that will not cease to surprise and entertain.