While occasional are a common and normal responses to waking , more frequent disturbed dreams and nightmares may be indicative of underlying psychopathology. In the more benign case, the frequency and intensity of disturbing dreams may show a progression and resolution over time, whereas chronic nightmares are repetitive, persistent, and associated with lower psychological well-being, as well as histories of trauma or abuse.1

In fact, frequent and distressing nightmares, along with several other qualities of disturbed , such as changes in emotional intensity, increased bizarreness, or unusual character interactions, have been associated with specific psychological disorders, including , schizophrenia, and .

Depression

Perhaps unsurprisingly, depressed patients report dreams with more negative mood and emotion than control subjects, as well as more failures and misfortunes (compared to people with schizophrenia).2,13 Patients with depression also experience more frequent nightmares.4,14

Further, depressed patients with a history of thoughts or behaviors report more death themes in their dreams. However, one study found that depressed patients reported less negative, but more neutral affect in their dreams; the authors interpret this finding to be consistent with the affective flattening seen in depression. Further, one study of found that shifts from neutral or negative dream content (as in depression) towards more bizarre and unrealistic dreams can predict alterations between depressive and states.16 This suggests that shifts in affective content of dreaming may occur congruently with vacillations in waking mood in depression.

Besides affective content, depressed patients have been found to play a relatively passive role in their dreams, along with reporting less bizarre dreams, lower dream recall frequency, and less detailed dream reports.17,18 One study repeatedly awakened depressed patients five minutes into REM sleep episodes—a period that typically promotes high dream recall—and found that depressed patients were consistently unable to recall their dreams.19 These findings altogether are suggestive of a relative inhibition or flattening of dream content in depressed patients.

Schizophrenia

Several studies have found the dreams of schizophrenic patients to contain heightened levels of anxiety and negative affect. For instance, they report higher frequencies of hostility in their dreams in comparison to controls—specifically, increased hostility directed toward the dreamer.2,3 They also have more frequent nightmares than healthy subjects.4,5

When assessing the character involvement in the dreams of , several studies have found presence of more strangers and fewer familiar characters or friends—as well as an idiosyncratic finding that the patient is often not the main character of the dream.6-9 The combination of and apprehensive dreams with perceived hostility from strangers and unfamiliar characters is consistent with experiences of persecutory delusions in waking life.

Reports on bizarreness have been inconsistent. Some studies report more bizarreness and implausibility in the dreams of people with schizophrenia, while others find no differences in bizarreness compared to controls.10-12 This inconsistency may be due to the methodology use for rating dream bizarreness; for instance, one study showed that schizophrenics self-rate their dreams as less bizarre than judges do (perhaps because they are so used to how bizarre their dreams are).8 On the contrary, waking daydreams are consistently found to be more bizarre in schizophrenic patients.

In general, the increased negative affect, higher frequency of nightmares, and unusual character profile of patients’ dreams is consistent with waking symptoms of schizophrenia.

Borderline Personality Disorder

Patients with experience more negative dreams, as well as more distress within their dreams and after awakening from dreams.20,21 Further, BPD is consistently associated with higher-than-average nightmare frequency,20-22 and increasing nightmare frequency is associated with more severe symptoms.23 Some researchers suggest that these chronic nightmares may be related to experiences, which are often implicated in the development of borderline disorder.24

However, in another study, character interactions in the dreams of borderline patients were found to contain more friendliness and less aggressiveness, as well as less confusion than control subjects dreams.25 They also contained heightened levels of sensory vividness, including movement and auditory attributes.

These findings seem somewhat contradictory to the prevalence of nightmares and anxious, distressing dreams, but could be indicative of a general intensification of dreaming processes that may result in either nightmares or vivid non-nightmare dreams, depending on current levels of stress.

Clinical Implications

Patterns in disturbed dreaming may be useful as indicators of progression. For instance, increasing reference to death in the dreams of depressed patients could reveal the presence of suicidal thoughts, and is thus a potent cue for clinicians—especially since nightmares themselves are associated with greater risk for suicide.22

On the other hand, shifts towards more positive themes may be indicative of successful treatment. As mentioned, in bipolar disorder, shifts from negative to bizarre dreams may reflect shifts from depressive to manic states, and can thus alert the patient and clinician to oncoming symptoms.16

The prevalence of nightmares in all three psychological disorders examined here further suggests that treatments incorporating targeted nightmare reduction may be more successful than those that neglect nightmares. In general, assessment of dreams can serve as a useful barometer for changes in psychopathology and can thus be effectively used within treatment contexts.