Most people occasionally wake up from a scary or unpleasant dream which may lead them to wonder about the cause of nightmares and how to deal with them. Although nightmares, or “bad dreams” occur most frequently in children, adults can also experience, or even be plagued by, bad dream scenarios such as falling from a great height or being chased by some dangerous element that they cannot escape. Frequent nightmares can have a debilitating effect on your daytime ability to concentrate and perform daily activities, and even on your general emotional stability. Getting information on the cause of nightmares is an excellent first step in treating them, so I’ve tried to compile a short guide that you can use to figure out what might be the cause of nightmares for you.
Sleep researchers have divided the cause of nightmares into two categories: physical causes and psychological causes. For the average person, there is probably overlap between these two areas, as physical habits and cognitive habits (ways of thinking) are complementary and influence each other, but for clarity I’ll tackle them separately.
Since the content of our dreams and the quality of our REM sleep is directly linked to brain chemistry, drugs that alter the chemistry of the brain can be one cause of nightmares. Certain kinds of SSRI-based antidepressants, narcotics, or stimulants like cocaine may all potentially be a cause of nightmares because these drugs work on the brain. Withdrawal from drugs or alcohol can trigger similar changes in brain chemistry that can lead to nightmares. A snack eaten right before bed can also increase the chance that you will experience a nightmare. Researchers think a midnight snack may potentially be another cause of nightmares because it speeds up your metabolism right before you sleep, putting your brain in a more active state as you enter REM.
Any factor that interferes with getting a good quality of sleep can also be a cause of nightmares. Sleeping in an uncomfortable position, general discomfort due to illness, especially when it comes with a fever, or disorders that disrupt sleep such as sleep apnea or restless leg syndrome have been tentatively linked by scientists to increased incidence of nightmares. Taken together, the evidence suggests that sleep disruption or deprivation may be a root cause of nightmares for many sufferers; some sleep researchers have even hypothesized that nightmares may be an early warning sign that you are suffering sleep deprivation and need to get more and better sleep each night. Because sleep deprivation can have long-term health effects such as increased risk of developing heart disease or obesity, it might be a good thing to figure out if sleep deprivation might be the physical cause of your nightmares so you can take steps to alleviate the problem.
What do you do, however, if your nightmares are disrupting a good night sleep and you can’t find a definite physical cause for them? If this is the case, the cause of nightmares might be psychological. If you’ve experienced a traumatic event in waking life, such as an attack, serious accident or the death of a loved one, these can all feed into nightmares. Psychological disorders like depression, anxiety, and PTSD (Post-Traumatic Stress Disorder) have all been shown clinically to either be a cause of nightmares or to include nightmares as a component. The distinction is unclear, but there’s good evidence to suggest that frequent nightmares can worsen the symptoms of anxiety and depression.
For most people, as important as identifying the cause of nightmares is finding a way to treat them. Physical and mental stress seems to be a main cause of nightmares, so reducing your level of daily stress is a great way to get rid of bad dreams: regular exercise (especially centering exercises like yoga) and meditation can help you alleviate stress, as well as setting yourself a regular sleep-wake schedule. Avoid performing stressful activities like work or studying in your bedroom in order to make it a tranquil place reserved for sleep and relaxation. These methods will train your brain to fall asleep sooner and to stay more deeply asleep.
There are also powerful cognitive techniques that can help you to banish nightmares, change them into positive dreams, or explore them to get to the underlying cause of nightmares you may experience. You may sometimes wake up from a nightmare afraid to go back to sleep for fear that the bad dream might resume. Some dream workers advocate trying to neutralize the nightmare by envisioning a pleasant scenario or scene you would like to dream about instead as you fall back asleep.
People affected by disorders like PTSD have greatly benefited from a cognitive therapy called imagery rehearsal treatment: this treatment has the nightmare sufferer imagine, while awake, an alternate and more positive ending to their nightmares. As they go to sleep, the person meditates on this positive outcome and repeats their intention to enact it if they fall into a nightmare. Imagery rehearsal therapy has had great success since it was first introduced as a therapy, not just in reducing nightmares, but also in reducing everyday stress for people suffering from PTSD. This suggests to me that a huge cause of nightmares is a sense of inability or powerlessness in a person’s waking life. If you’re going through a stressful time in your life marked by bad dreams at night, taking what action you can to influence those dreams can be an empowering way to both stop nightmares and to reduce your level of daily stress.