Nightmares matter: rethinking suicide risk assessment and intervention in depression

Nightmares are strongly linked to depression and suicide risk, yet they are rarely assessed or treated in clinical practice. Up to 90% of people with major depressive episodes experience nightmares, which are among the strongest predictors of suicide attempts. Dream alterations often precede suicidal crises. Imagery rehearsal therapy (IRT), a first-line treatment for nightmare disorder, reduces nightmare frequency and emotional distress, and may also improve depressive and suicidal symptoms by reducing emotional burden, improving sleep quality, and decreasing anxiety. The authors argue that nightmares should be considered a core, modifiable risk factor for suicide and that systematic assessment and treatment of nightmares could be a valuable suicide prevention strategy.

Study at a glance

Abstract

Nightmares are repeated and lengthy dreams, extremely dysphoric, with clear memory, typically involving life-threatening threats to safety or physical integrity. These nightmares lead to significant distress upon awakening and may substantially impact daytime functioning. Both the experience of these dreams and the sleep disruption produced by the ensuing awakening cause significant impairment in daily life and functioning [1–3]. Nightmares are highly prevalent, affecting up to 45% of the general population, and are strikingly overrepresented among individuals experiencing a major depressive episode (MDE), with prevalence estimates exceeding 90% in some populations, especially among individuals with more severe clinical profiles, including those with melancholic features or suicidal ideation [4]. In patients with depression and nightmares, themes often revolve around despair, loss, or death. Nightmares are consistently associated with greater emotional intensity, higher depressive and anxiety symptom severity, increased nighttime awakenings, and insomnia, further exacerbating the despair and fatigue characteristic of depression, as well as a markedly elevated risk of suicidal thoughts and behaviors [5, 6]. Among sleep-related symptoms, nightmares have emerged as one of the strongest clinical predictors of suicide attempts [5, 7–13]. Importantly, qualitative alterations in dream content—including a progression toward recurrent nightmares and explicitly suicidal dream scenarios—often precede suicidal crises, with approximately 80% of patients exhibiting dream alterations in the months leading up to a crisis [7]. These findings suggest that nightmare pathology may actively contribute to the escalation of suicidal risk rather than merely reflecting overall illness severity. These associations operate across the lifespan. Adolescence, however, represents a particularly vulnerable developmental window. Heightened emotional reactivity, ongoing brain maturation, and instability of sleep–wake rhythms may amplify the impact of nightmares on affective regulation and suicidal vulnerability [10, 14]. Parasomnias, including nightmares, are highly prevalent in adolescents and often more emotionally intense than in adulthood [15]. Together, these developmental features suggest that the relationship between nightmares, depression, and suicidal ideation in adolescents not only mirrors that observed in adults, but may also amplify and exemplify shared pathophysiological mechanisms linking disturbed dreaming, mood dysregulation, and suicidal risk, making adolescence a particularly informative and critical period for investigation [16, 17]. Despite this growing body of evidence, nightmares remain largely neglected in routine psychiatric care [18]. They are rarely systematically assessed and even more rarely targeted therapeutically in patients with depression or suicidal ideation [19]. Notably, nightmares are largely absent from the core suicide risk factors emphasized in major international clinical guidelines and assessment frameworks, including recent recommendations from the American Psychiatric Association, NICE, and WHO, where sleep disturbances are mentioned only marginally or nonspecifically, and nightmares are not identified as an independent or actionable risk marker [20–23]. This gap is striking, given that nightmares represent not only an early-emerging symptom but also a dynamic marker of acute risk, recurrence, and poor prognosis [7, 8, 14]. Their persistence may reflect a failure of nocturnal emotional processing, reinforcing maladaptive fear conditioning and negative affect that extend into daytime functioning [24]. From this perspective, nightmares should be considered a core clinical feature of depressive disorders and suicidal crisis, with important prognostic and therapeutic implications, rather than a secondary or ancillary symptom. Imagery rehearsal therapy (IRT) is currently recommended as the first-line treatment for nightmare disorder, with or without trauma, and has demonstrated robust efficacy in reducing nightmare frequency, emotional distress, and sleep disruption [25–29]. IRT posits a seamless connection between waking life and dream states, allowing the brain to integrate daytime experiences into nocturnal narratives. It also treats nightmares as modifiable behaviors, enabling cognitive and behavioral restructuring through exploration of nightmare scenarios with positive mental imagery. Beyond its established effects on nightmares, we observed in a recent controlled study with sleep education IRT improved nightmares in a depressed population across all the subdimensions, clarifying its impact not only on nightmares frequency but also on emotional, nocturnal, and diurnal impacts [30–33]. Interestingly, IRT has also been associated with improvements in overall psychiatric symptoms and sleep disturbances, including depressive, anxiety, and suicidal symptoms [33]. The potential mechanisms by which IRT reduces suicidality in patients with depression and nightmare disorder appear multifactorial. First, IRT may reduce the emotional impact of nightmares, a factor more strongly correlated with depression and suicidal ideation than frequency alone [31]. By transforming distressing emotional content through cognitive restructuring and positive imagery, IRT may alleviates the nocturnal emotional burden that fuels daytime hopelessness and despair. Second, IRT may improve core depressive symptoms, including anhedonia, guilt, and negative thought patterns, reducing cognitive and emotional vulnerability to suicide [30]. These effects likely arise from interrelated cognitive, emotional, and physiological mechanisms that converge on emotional processing and modification of the fear structure underlying nightmares [34]. In this framework, IRT facilitates fear extinction, and promotes the development of new cognitive and emotional associations necessary for memory integration [34]. Third, the therapy may decrease anxiety symptoms, which frequently co-occur with depression and independently increase suicidal risk. A key mechanism is the reduction of physiological and emotional arousal, occurring both before sleep—by decreasing anticipatory anxiety, facilitating sleep onset, and reducing unhelpful cognitions related to nightmares—and during sleep, by lowering the likelihood of nightmare activation and allowing greater flexibility of the fear structure [34]. Reduced arousal supports fear extinction processes and improves emotional regulation both nocturnally and diurnally. Fourth, IRT may improve sleep quality—including efficiency, duration, and sleep-related worry—targeting a major and often underestimated suicide risk factor [31]. Poor sleep intensifies emotional dysregulation, rumination, and cognitive distortions, all of which drive suicidal thinking. Improved sleep quality may allow emotional processing to occur during sleep, potentially enhancing fear extinction, emotional regulation, and memory consolidation [34]. In this sense, restoration of sleep functions may act as a complementary pathway through which emotional processing continues while asleep, reinforcing daytime therapeutic gains. Thus, by acting on these interconnected pathways—depression, anxiety, emotional distress, and sleep dysfunction—IRT may exert a protective effect against the onset or escalation of suicidal ideation. These findings support the idea that IRT is not merely a treatment for nightmares but a potentially valuable intervention for reducing suicide risk in vulnerable depressive populations. Given the strength and consistency of the association between nightmares in depression and suicidal behavior, and the emerging therapeutic effects of IRT, a compelling hypothesis emerges: targeted treatment of nightmares may reduce the depressive symptom burden, decrease suicidal ideation, and lower the risk of recurrent suicidal crises in both adolescent and adult patients with MDE and frequent nightmares. Such an approach challenges traditional symptom hierarchies in psychiatry, positioning nightmares not as epiphenomena but as modifiable drivers of illness course and clinical outcome. While further large-scale trials will be essential to refine indications and quantify effects on suicidal outcomes, the current body of evidence is already sufficient to support a meaningful shift in clinical practice toward the systematic assessment and treatment of nightmares in high-risk patients (Figure 1). When treating nightmares prevents suicide. In conclusion, from both clinical and public health perspectives, nightmares constitute a well-established yet critically underexploited target for suicide prevention. Despite their robust and consistent association with suicidal behavior across populations and developmental stages, nightmare-focused interventions have not yet been formally tested with suicide-related outcomes as primary endpoints. Well-powered randomized controlled trials are now urgently needed to definitively determine whether treating nightmares can reduce depressive symptom burden, suicidal ideation, and the recurrence of suicidal crises. Demonstrating such effects would not only validate nightmares as a modifiable driver of suicidal risk, but would also establish a novel, scalable, and low-risk preventive strategy for high-risk populations, inform future clinical guidelines, and decisively advance the integration of sleep medicine and psychiatry in the prevention and management of mood disorders and suicide. The authors declare that they did not receive any funding for this work. Financial disclosure: The authors report no financial relationships or competing financial interests relevant to this work. Non-financial disclosure: The authors have no nonfinancial interests that could be perceived as influencing the submitted work.