Night owls are more likely to experience anxiety and depression than early birds and take longer to recover from work.

People with a pronounced evening chronotype not only report more symptoms of anxiety and depression, but also experience poorer recovery after work, and their work is more likely to "bleed into" their personal lives. This is the conclusion reached by researchers from the University of Eastern Finland, the Finnish Institute for Health and Welfare, the Finnish Institute of Occupational Health, and Karolinska Institutet. The study, published in the journal Sleep Health, is based on data from 2,266 working adults in Finland. [1]

The differences were particularly pronounced among people who clearly considered themselves "night owls." Compared to pronounced morning types, they were more likely to experience sleep deprivation, greater social jet lag, poorer recovery between workdays, and more likely to exhibit signs of psychological distress. These associations persisted even after accounting for age, gender, insufficient sleep, low physical activity, and risky alcohol use. [2]

One of the most interesting findings concerns anxiety disorders. Statistical analysis revealed that poor recovery after work explained approximately 12.7% of the association between a more evening-oriented chronotype and anxiety disorders for which people sought medical help. In other words, some of the increased mental health risk among night owls may be related not only to intrinsic biological characteristics or lack of sleep, but also to how well work life aligns with their natural circadian rhythm. [3]

However, the study does not prove that the evening chronotype per se causes depression or anxiety disorder. This is an observational population-based study, and most of the characteristics studied were assessed simultaneously. A reverse relationship is also possible: for example, anxiety or depression themselves can impair sleep, the ability to switch off from work, and subjective recovery. Therefore, the authors view work-life balance primarily as a potentially modifiable variable worth testing in future intervention studies. [4]

Research in numbers

Parameter	Meaning
Participants	2266
Age	20-65 years old
Middle age	44.3 years
Women	57.1%
Pronounced morning type	413 people
Moderate morning type	659
Moderate evening type	735
Pronounced evening type	459
Healthy Finland analysis period	2022-2023
Proportion of the association between chronotype and treated anxiety explained by recovery from work	12.7%
Magazine	Sleep Health
DOI	10.1016/j.sleh.2026.03.001

[5]

What is chronotype and why is being a night owl more than just a habit of staying up late?

Chronotype reflects individual differences in the body's circadian rhythm. Morning types typically experience peak alertness and performance earlier in the day: they naturally wake up earlier, want to sleep earlier in the evening, and function better in the morning. In evening types, these processes occur later. This is related to the body's circadian system, although actual sleep time is also significantly influenced by work, family, light, social habits, and lifestyle. [6]

In the Finnish study, chronotype was determined using a single, widely used question from the Morningness-Eveningness Questionnaire. Participants were asked to select one of four options: "definitely a morning person," "rather a morning person," "rather an evening person," or "definitely an evening person." This created four groups, rather than simply two categories of "larks" and "owls." [7]

The group of pronounced "night owls" included 459 participants, or about one-fifth of the sample studied. Another 735 people considered themselves to be more of an evening person. The authors note that using a single question may slightly overestimate the prevalence of pronounced evening behavior compared to a more comprehensive six-item scale, so these percentages should not be automatically generalized to the entire population. [8]

Moreover, the division itself corresponded well to the actual sleep patterns. The average sleep midpoint on non-working days was approximately 2:54 a.m. for pronounced morning types and 4:57 a.m. for pronounced evening types. Social jet lag also increased with the shift toward evening: approximately 20 minutes for extreme "larks" versus approximately 1 hour 25 minutes for extreme "owls." [9]

How did the four chronotypes differ?

Indicator	Pronounced morning	Moderate morning	Moderate evening	Pronounced evening
Number of participants	413	659	735	459
Middle age	48.2	45.2	42.8	41.9
Women	62.7%	58.3%	53.1%	56.6%
Insufficient sleep	19.0%	21.8%	24.4%	38.6%
Physical activity below recommendations	46.7%	51.5%	53.0%	58.0%
Risky alcohol consumption	27.3%	22.8%	27.3%	32.3%
Mid-sleep on free days	02:54	03:31	≈04:04	04:57
Social jet lag	0:20	0:57	1:08	1:25

[10]

Nearly 39% of severe night owls reported a lack of sleep

Differences in the duration and quality of recovery were particularly noticeable. Among pronounced evening sleepers, 38.6% reported rarely or never getting enough sleep. For pronounced morning sleepers, the figure was only 19%. Thus, subjective sleep deprivation was approximately twice as common among extreme night owls. [11]

One possible cause is so-called social jet lag. An evening person's biological clock may push them, for example, to fall asleep around 1 or 2 a.m. and wake up later in the morning. But a standard workday requires waking up at 6 or 7 a.m. On weekends, people return to a more natural schedule, and their sleep time shifts sharply. The effect is reminiscent of jet lag.

This explains why evening types can suffer from sleep deprivation even without classic insomnia. They are able to sleep normally if allowed to choose their own time, but are forced to regularly interrupt their sleep due to an early work schedule. Previous research by the same group has already shown that insufficient sleep partially explains the link between evening types and mental disorders and reduced performance. [12]

However, new research has shown that sleep deprivation alone is not enough to explain the entire picture. After statistically accounting for insufficient sleep, physical activity, and risky alcohol consumption, the associations between evening chronotype and work-life balance issues and several mental health indicators persisted. Therefore, the researchers focused on another possible mechanism: the inability to fully recover from workload. [13]

What can happen when the chronotype and schedule do not match?

Stage	Possible consequence
Natural sleepiness comes late	The person falls asleep later
The job requires early rising.	Sleep is shortened
On weekends, sleep shifts to a later time	Social jet lag is on the rise
Work activity occurs at biologically less optimal hours	More fatigue
After work there remains a pronounced fatigue	Worse recovery
Work continues to occupy my thoughts and free time.	Work-life balance is disrupted
Chronic repetition	May contribute to psychological stress

The "owls" recovered worse after a working day

The authors found the issue of recovery particularly important. Participants were asked, "Do you recover from the workday's stress by the next day?" Responses were given on a scale from zero (not at all) to ten (completely). The researchers also assessed the extent to which work negatively interferes with personal life. [14]

Pronounced evening types demonstrated statistically significantly worse recovery from work than pronounced morning types. This difference persisted after accounting for gender, age, insufficient sleep, low physical activity, and risky alcohol consumption. Similarly, extreme "owls" were more likely to experience negative work spillovers into their free time. [15]

The authors suggest that evening workers may expend more resources performing professional tasks at times when their biological readiness for activity is not yet high enough. If work starts at a fixed time, they have virtually no opportunity to postpone the most demanding tasks until their natural peak of alertness. This can result in greater fatigue by the end of the workday.

Recovery, however, isn't just about sleep. It includes the ability to psychologically disconnect from work-related tasks, reduce physiological and emotional stress, and replenish resources for the next work shift. A large meta-analysis of studies on employee availability outside of work hours has previously linked persistent work interference with poorer recovery, well-being, and life balance. [16]

What work factors were studied?

Indicator	What does it mean?
Work-life spillover	How much does work negatively interfere with personal life?
Recovery from work	How long does it take for a person to recover before the next working day?
Social jet lag	The difference between sleep time on workdays and non-workdays
Insufficient sleep	Subjective feeling of lack of sleep
Chronotype	Preference for earlier or later mode
Mental health	Questionnaires + real requests for medical care

The risk of depression and anxiety was particularly pronounced in extreme evening types

The authors did not limit themselves to the question "Do you feel depressed?" Mental health was assessed using several independent measures. They used the Mental Health Inventory-5, the GAD-7 Anxiety Scale, the PHQ-9 Depressive Symptom Questionnaire, a separate question on suicidal ideation, and data from national medical registries on actual help-seeking for depressive and anxiety disorders. [17]

In medical registries, 140 of 2,266 participants were treated for depression, and 257 for anxiety, stress-related, or somatoform disorders. A pronounced evening chronotype was associated with both types of visits, as well as with psychological distress, increased anxiety, and suicidal ideation. [18]

The association with treated depression was particularly strong. After accounting for gender, age, insufficient sleep, physical activity, and risky alcohol use, the odds of having registered depression treatment were approximately 4.2 times higher among severe night owls than among severe morning types: odds ratio 4.2, 95% confidence interval 1.9-9.0. Among moderate evening types, the odds ratio was approximately 3.0. [19]

However, these figures cannot be interpreted as "night owls have a 4.2 times higher causal risk of developing depression." The odds ratio is derived from an observational model and compares groups within a specific sample. Furthermore, the wide confidence interval indicates significant statistical uncertainty. The significance of the result is primarily that the association persisted after accounting for several important lifestyle factors. [20]

Mental health in research

Indicator	How was he assessed?
Psychological distress	MHI-5
Generalized anxiety	GAD-7
Depressive symptoms	PHQ-9
Suicidal thoughts	A separate question
Treated depression	National medical registries
Treated anxiety disorder	National medical registries
Pronounced evening chronotype and treated depression	OR 4.2; 95% CI 1.9-9.0 after full adjustment
Moderate evening chronotype and treated depression	OR 3.0; 95% CI 1.4-6.5

[21]

Work intrusion into personal life was associated with all studied indicators of mental ill-being

Regardless of chronotype, poor work-life balance was associated with virtually all psychological outcomes studied. The more work-related responsibilities interfered with leisure time, the more frequently psychological distress, anxiety, depressive symptoms, suicidal ideation, and registered treatment for mental disorders were observed. [22]

A similar pattern was observed for inadequate recovery. Participants who found it more difficult to recover from the workday's stress by the following morning were also more likely to have signs of anxiety and depression. These associations persisted after statistical adjustment for age, gender, sleep, physical activity, and risky alcohol use. [23]

For psychological distress, anxiety, and depression scales, the association with poor recovery was quite consistent. For example, in a fully adjusted model, worsening recovery scores were associated with odds ratios of approximately 1.5 for psychological distress and depressive symptoms and 1.4 for generalized anxiety per unit of the scale used by the researchers. These values characterize the statistical association between the scales and do not mean that worsening recovery automatically increases individual risk by exactly 40-50%. [24]

Interestingly, the problem was not unique to night owls. Negative work interference with leisure time and poor recovery were associated with mental health across different chronotypes. Night owls stood out primarily because they experienced these problems more frequently, along with a higher baseline prevalence of certain mental disorders. [25]

Work Balance and Mental Health

Mental outcome	Work-life spillover	Poor recovery
Treated depression	The connection has been identified	The connection has been identified
Treated anxiety	The connection has been identified	The connection has been identified
Psychological Distress MHI-5	The connection has been identified	The connection has been identified
GAD-7 alarm	The connection has been identified	The connection has been identified
Depression PHQ-9	The connection has been identified	The connection has been identified
Suicidal thoughts	The connection has been identified	The connection has been identified

[26]

Poor recovery explained part of the link between eveningness and anxiety disorders.

One of the most important statistical analyses in the study was a mediation analysis. Its purpose was to test whether part of the relationship between chronotype and mental health was mediated by a third factor—in this case, the ability to recover from work. [27]

The result was significant for anxiety disorders registered in the healthcare system. According to the researchers' calculations, recovery from work explained approximately 12.7% of the overall association between chronotype and treated anxiety. This is a small but potentially important proportion, since, unlike an innate tendency to be a "night owl," work conditions and recovery opportunities can theoretically be modified. [28]

No convincing mediating effects of recovery were found for other mental health indicators. This is an important limitation of this sweeping conclusion: the study did not show that poor work-life balance explains the entire increased incidence of depression and anxiety in evening types. Rather, it is one of several possible mechanisms, along with sleep deprivation, circadian misalignment, individual psychological characteristics, and other factors. [29]

It's also important to distinguish between mediation and causality. A statistical model can show that the data are consistent with the sequence "evening chronotype → poorer recovery → more anxiety disorders," but when most variables are measured simultaneously, it cannot prove this exact direction. For example, anxiety itself can make it difficult to switch from work thoughts in the evening. The authors therefore discuss the potential role of a mechanism rather than a proven causal chain. [30]

What does the 12.7% figure mean?

Interpretation	Right?
12.7% of night owls will definitely develop an anxiety disorder.	No
Work causes 12.7% of all anxiety disorders	No
Poor recovery statistically explained 12.7% of the observed association of chronotype with treated anxiety.	Yes
The rest of the relationship remains unexplained by this factor.	Yes
The result proves causality	No
The factor is potentially interesting for preventive interventions	Yes

Why the standard 8:00 AM to 5:00 PM schedule may be less convenient for night owls

The human circadian system regulates sleepiness, alertness, body temperature, hormone secretion, and many aspects of cognitive performance. In evening types, most of these processes are delayed. Therefore, the pressure to demonstrate peak productivity very early in the morning may fall during a subjectively unfavorable part of the biological 24-hour period.

Modern working society is predominantly organized around the early or moderately early chronotype. School and many work shifts begin in the morning, and freedom to independently determine the start of the workday is limited. Researchers suggest that this social schedule may create additional strain for some pronounced evening types. [31]

This phenomenon is sometimes called circadian misalignment. A person is forced to wake, eat, work, and sleep at times that don't fully align with their internal biological signals. If repeated regularly, this can increase social jet lag and the need to "catch up on sleep" on free days.

However, the study doesn't conclude that all night owls should be transferred to evening shifts. Night work itself can disrupt circadian rhythms and be associated with adverse health effects. The authors believe that a more reasonable focus for future research is flexibility in start times, the ability to better distinguish between work and free time, and adequate recovery, rather than simply converting evening workers into night workers. [32]

Possible areas of work adaptation

Approach	Potential target
More flexible start to the working day	Reduce conflict with chronotype
Limit work messages in the evening	Improve psychological disconnection from work
Sufficient intervals between shifts	Improve recovery
The ability to do some of the work later	Take advantage of periods of peak energy
A stable sleep pattern	Reduce social jet lag
Individual approach	Don't consider one schedule optimal for everyone

The study does not prove that "owls need to be treated"

An evening chronotype is not a mental disorder or disease in itself. It is a variation of an individual's circadian rhythm organization. Rather, the risk arises from a complex interaction of biological preferences, sleep, social demands, work environment, and individual health factors.

It's especially important not to confuse the evening chronotype with insomnia or delayed sleep phase syndrome. A person can be a healthy night owl, regularly getting the required number of hours of sleep, and functioning well if their social schedule allows for a later bedtime and a later rise. A clinical problem arises when a person chronically fails to get the sleep they need or adapt to a mandatory schedule.

The authors therefore do not propose medication to "turn night owls into larks." The practical idea of the study is entirely different: if a certain group of workers statistically exhibits poorer recovery and is more likely to experience work-life conflict, then changing the work organization may prove a potential preventative intervention. This question still needs to be tested in randomized or longitudinal studies. [33]

Ilona Merikanto, head of the research team, notes that understanding particularly vulnerable workers could potentially allow for more precise interventions to improve work-life balance and recovery after work. According to the researchers, this could contribute not only to mental well-being but also to reducing inequality in the workplace. [34]

What the study doesn't show

Statement	Scientific assessment
All night owls have mental problems.	No
Evening chronotype is a disease	No
Work has been proven to cause depression in night owls.	Not proven
Night owls must work at night.	No
Lack of sleep completely explains the results	No
Work-life balance can be part of the mechanism	Yes, the data supports it.
Interventional and longitudinal studies are needed	Yes

Important limitations of the study

The first limitation is its primarily observational and cross-sectional nature. Although medical diagnoses were taken from national registries, chronotype, recovery, work-life spillover, and many other indicators were assessed within a single period. Therefore, it is impossible to reliably determine the direction of causality. [35]

The second limitation relates to self-reporting. Chronotype was determined by a single question, and sleep, physical activity, and recovery were also largely based on participants' responses rather than on long-term actigraphy, melatonin measurements, or objective activity monitoring. The authors acknowledge that a single question on chronotype may somewhat overestimate the number of pronounced evening types. [36]

The third issue is the size of individual subgroups. The overall sample of 2,266 participants is large enough for population analysis, but becomes significantly smaller when divided into four chronotypes and simultaneously into mental illness categories. For example, depression treatment was reported for only 140 participants. This explains the relatively wide confidence intervals for some estimates. [37]

Finally, the participants were working adults in Finland. Social norms, working hours, workday length, and cultural perceptions of work-life balance vary significantly between countries. The authors explicitly warn that before extending the findings to non-European and especially non-Western societies, the results need to be replicated in other populations. [38]

Strengths and Limitations

Strong point	Limitation
A population-based sample of working adults	One country
2,266 participants of various professions	Not a very large sample for complex interactions
Validated MHI-5, GAD-7, and PHQ-9	Many variables are based on self-report.
National medical registries	Observational design
Taking into account gender and age	Reverse causality is possible
Correction for sleep, activity and alcohol	It is impossible to exclude all confounding factors
Evaluation of mediation and moderation	Mediation alone does not prove causation

What does the study add?

The link between an evening chronotype and mental health has been known for years. A previous large Finnish study of over 18,000 adults found that severe night owls were more likely to experience depressive and anxiety symptoms, diagnoses, and even hospitalizations for mental disorders. Part of this risk was attributed to insufficient sleep. [39]

A new study takes this a step further: it asks what's happening specifically in work life. The results show that evening types are more likely to experience poor recovery and work spilling over into their free time, and these differences can't be entirely attributed to sleep deprivation, alcohol, or low physical activity. [40]

This changes the potential prevention point. Changing a genetically and biologically determined chronotype is difficult and not always necessary. However, changing the duration of rest between shifts, employee availability after work, flexibility in starting work, and the ability to psychologically disconnect from work tasks is theoretically much easier.

The next logical step would be studies that actually alter work conditions and then observe whether sleep, recovery, and mental health improve, particularly among evening types. Until that happens, the new publication provides a compelling hypothesis and population associations, but not a ready-made prescription for treatment or worktime management. [41]

The main conclusion

Question	Answer
Were "owls" more likely to have mental problems?	Yes
Were they more likely to experience sleep deprivation?	Yes
Did they recover worse after work?	Yes
Did work interfere with their personal lives more often?	Yes
Can everything be explained only by dreams and lifestyle?	No
Did recovery explain some of the connection with anxiety?	Yes - about 12.7%
Has changing your schedule been proven to prevent depression?	Not yet
Is personalized work schedules worth exploring?	Yes, this is one of the practical consequences of the work

News source

Merikanto I., Partonen T., Vanttola P., Virtanen M. The role of recovery from work and work-life spillover in the association between chronotype and mental health problems: A population-based study. Sleep Health. 2026;12(3):488–495. The article was first published online March 25, 2026. DOI: 10.1016/j.sleh.2026.03.001

The study was conducted using data from the Healthy Finland Study, a population-based study. The study was funded by the Finnish Work Environment Fund, grant 240065, recipient: Ilona Merikanto.