When someone says, “I slept badly,” it can mean a dozen different things. Maybe they had trouble falling asleep, or perhaps they kept waking up throughout the night. They might have slept too much and still felt groggy, or their sleep was interrupted by vivid dreams. Poor sleep over time negatively impacts cognition and emotions, and is known to cause or worsen mental health issues. Beyond typical “bad sleep” aspects, factors like being a night person, or having a large difference in sleep timing between workdays and days off (known as social jetlag), are also linked to mental health problems. A better understanding of the types of sleep patterns and problems in relation to different mental health symptoms is important, particularly since it can help us improve current treatments by targeting specific or multiple sleep aspects. This will, in turn, be important for how we can reduce mental ill-health symptoms in the general population and prevent the development of psychiatric disorders.
The study: Sleep profiles and mental health in non-diagnosed individualsIn our recent paper published in Translational Psychiatry, we assessed the relationships between sleep and mental health in individuals without a formal psychiatric diagnosis. Our aim was to describe the sleep patterns and problems one can expect in individuals with increasing degrees of different mental ill-health symptoms. We did not focus on formal diagnoses but on how mental-ill health varies in the population. This so-called dimensional approach aligns with contemporary frameworks that view mental health on a continuum, emphasizing the importance of understanding variations in individuals that are not diagnosed with a disorder.
We assessed 440 participants (341 women, 97 men, 2 non-binary) on eight aspects of sleep and 13 sets of symptoms that are common in several psychiatric disorders. These symptoms included, among others, those prevalent in mood disorders such as depression and mania, anxiety disorders like social anxiety and generalized anxiety, compulsive behaviors and intrusive thoughts such as obsessive compulsive disorder (OCD), eating disorder, and psychosis, and neurodevelopment disorders such as ADHD and autism.
Key findingsOur main findings are that individuals with more symptoms characteristic of mood and anxiety disorders, and ADHD showed the worst overall sleep patterns and were an evening person, with depression being at the top of the list. In contrast, individuals with more symptoms characteristic of autism, eating disorder, and impulsivity had milder sleep problems. Having more symptoms characteristic of mania was linked to being a morning person and better sleep , including less severe insomnia symptoms, less fatigue, more restorative sleep, and also a higher perception of adequate sleep. Whether this indicates a positive state associated with good sleep rather than a pathological level of mania remains to be determined.
Insomnia and fatigue were the two sleep problems most strongly associated with psychiatric symptoms, and this was particularly seen in individuals who had worse symptom levels of depression, emotion dysregulation, and anxiety. Non-restorative sleep, i.e., not feeling refreshed after sleep, was a prominent feature in individuals who also had symptoms of delusional ideation and OCD. Among the sleep features observed in relation to autism, being an evening person was the most noticeable. Social jetlag showed very modest associations with psychiatric traits, only marginally being associated with OCD, delusional ideation, and emotional instability.
Figure 1. These plots depict the sleep features associated with each psychiatric trait. A coefficient of 0 indicates no relationship. Lighter color intensities signify a stronger association. A higher sleep duration deviation indicates a deviation from the mean sleep duration of 7h39min (either shorter or longer sleep than the mean). Error bars represent 95% confidence intervals; if they touch zero, it indicates a non-significant relationship.
Implications for future research on prevention and treatmentA better understanding of differences in sleep patterns and problems is valuable for research aimed at developing targeted prevention strategies. The development of personalized medicine within sleep is important since there are many types of sleep problems and patterns, and individuals may benefit from different type of treatments. Identifying an individual’s specific sleep pattern is essential before deciding on a particular treatment strategy. Our study contributes with knowledge about the sleep patterns most likely to occur in relation to different mental disorders. For instance, those with more symptoms of depression, insomnia and fatigue emerged as the most prominent, suggesting that cognitive behavioral therapy for insomnia (CBT-I) may be best suited for most individuals, while others with patterns such as social jetlag combined with an evening chronotype may benefit more from interventions addressing circadian misalignment. The development of personalized medicine is important in this context, as it allows for tailored treatment plans that consider the unique sleep patterns and mental health profiles of individuals. Future research that integrates various therapeutic approaches and exploring the synergy between treatments in different individuals will be essential in refining personalized strategies.
Important considerationsCritical questions for our research field include how many nights of a particular sleep pattern are needed before it is associated with a mental health problem, and when interventions should be implemented. These are complex issues that will vary among individuals and also depend on factors like genetic predisposition, environmental and lifestyle influences, as well as personal resilience factors. It is also important to note that our study has not determined whether sleep contributes to the development of psychiatric symptoms, to what degree the psychiatric symptoms may have resulted in the observed sleeping patterns, or whether other factors may be behind these problems. While it has been suggested that poor sleep often leads to psychiatric problems, this is not the case for everyone.
This paper is an collaboration between researchers from Karolinska Institutet, Stockholm University (Sweden), and Netherlands Institute for Neuroscience (Netherlands)
For further insight, access the full paper here:
https://doi.org/10.1038/s41398-024-03009-4
Axelsson, J., van Someren, E. J. W., & Balter, L. J. T. (2024). Sleep profiles of different psychiatric traits. Translational psychiatry, 14(1), 284. https://doi.org/10.1038/s41398-024-03009-4