Do you dream in fragmented bursts of images or extended, vivid narratives? Do you remember dreams as if they really happened, or do you forget them immediately upon waking? What do dreams tell us about ourselves? There are a number of things that dreams can indicate about mental health, reflecting conditions ranging from general emotional states to serious mental disorders. Sometimes a dream is just a dream — but, in some cases, it may mean something more.
There’s a lot that we don’t know about dreaming. Despite famous theories by the likes of Sigmund Freud, experts still don’t really know what the images and impressions in dreams mean, or even if they mean anything at all. Even the most basic questions, like “Why do people dream?” continue to elude researchers, in part because sleep itself is not well understood. Though we know that sleep is essential to human health, its actual purpose — and the purpose of REM sleep, the sleep stage responsible for vivid dreaming — is still largely a mystery. Another factor that makes dreaming hard to pin down is that it’s difficult to study; though scientists can monitor brain activity while someone is dreaming, the actual content of a dream, as well as how vivid or disjointed a dream feels, can only be described by the dreamer in necessarily subjective terms. Since one person’s incredibly bizarre dream might be another person’s normal Tuesday snoozefest, coming up with quantitative research about dreaming is complicated, to say the least.
All of that said, studies have shown that certain types of dreaming can say a lot about what’s going on in our bodies and minds. Vivid dreaming, for example, sometimes accompanies sleep deprivation, low blood sugar, and pregnancy. Intense or stressful dreaming can also reflect your mental and emotional state.
It’s important to note that having vivid dreams or scary dreams is not in itself an indicator that anything is wrong with your mental health. Nightmares are a fairly common phenomenon among adults, and though they can be triggered by stress or anxiety, they are not necessarily linked to any greater mental health issue. In many cases, dreams are simply weird, but very common, aspects of being human. However, if you do have a mental health condition, certain types of dreaming may appear as one of your symptoms.
According to sleep researcher Michelle Carr, studies have shown that people suffering from depression experience “more negative mood and emotion” in their dreams than others, as well as more frequent nightmares. People who experience suicidal ideation in their waking lives also tend to have death as a recurrent theme in their dreams. However, depression doesn’t always impact dreaming in the same way. One study, for example, showed that, in some cases, people with depression experience a “neutral affect” in their dreams rather than an overtly negative one; researchers think this might be linked to the “affective flattening” that can occur in people with depression.
Disrupted sleep is a common symptom of bipolar disorder. “The overwhelming majority of people with bipolar have sleep problems,” Dr. Phillip Gehrman, a sleep specialist at the University of Pennsylvania in Philadelphia, told Everyday Health. In fact, he said that major sleep changes — from experiencing insomnia, to sleeping all the time, to needing less sleep than usual to stay alert — are often signals of an oncoming bipolar episode.
Unsurprisingly, these disturbances in sleep also affect people’s dreams. A 1995 study of patients with bipolar disorder found that dreams could even predict oncoming shifts in mood. “By categorizing the dreams that preceded mood shifts, we were able to identify a particular type of dream that seemed to precede a mood shift, particularly in the direction of mania,” researchers Kathleen M. Beauchemin and Peter Hays wrote. When people were heading into manic states, they tended to dream of “death and bodily injury.” Those moving into depressive episodes didn’t show a tendency toward common dream themes, but they did show a decrease in dreaming overall.
Like people with depression, people with schizophrenia experience more frequent nightmares than is typical. According to Carr, studies have shown that the dreams of schizophrenic people “contain heightened levels of anxiety and negative affect,” as well as “hostility directed towards the dreamer.” These dreams also are more highly populated with strangers (as opposed to friends or other people known to the dreamer) than usual.
Trauma is also closely linked to nightmares. People who develop post traumatic stress disorder (PTSD) following extremely stressful, traumatic experiences are more likely than the general public to experience recurrent nightmares; people with PTSD can have nightmares as often as five days a week or more. The shape of nightmares related to PTSD is different from typical nightmares. They tend to be similar to flashbacks, in which the dreamer re-experiences parts of or even whole traumatic events. At least half of people with PTSD have these “replicative nightmares,” repeatedly reliving moments of trauma.
If disturbing or nightmarish dreams are routinely interrupting your sleep, take the time to talk to your doctor about it. Your dreams may or may not be signs of a bigger problem, but you should seek help regardless, as frequently disrupted sleep can negatively impact your health. Dream researcher and clinical psychologist Antonio Zadra pointed out in The New York Times that recurrent nightmares need to be addressed simply for their own sake, even if they’re not signs of other issues, writing, “In some cases, nightmares represent a primary sleep disorder rather than a symptom of an underlying psychological conflict.” So whether you think your disturbed sleep is the result of depression or trauma, or your nightmares seem to crop up out of the blue, it’s worth talking to an expert — doing so might just help you to get some peaceful sleep.