Sleeping More but Still Feeling Tired Every Morning? It Could Be a Sign of a Specific Type of Depression
Joint research team from the University of Sydney and other institutions analyzes data from 11,380 adults with a history of depression
- Patients with pronounced hypersomnia and morning fatigue experienced earlier onset and reported poorer responses to antidepressants.
- Findings highlight the need for personalized treatments that take sleep patterns and circadian rhythms into account.
Could sleeping excessively and feeling exhausted every morning be clues to a specific subtype of depression? A joint research team from the University of Sydney and other institutions explored this question by analyzing data from 11,380 adults who had previously been diagnosed with depression. The researchers examined differences in symptoms, medication responses, and genetic characteristics among participants grouped according to their sleep patterns and circadian rhythms, investigating whether these distinctions could help guide more personalized treatment approaches.
The researchers analyzed participants’ self-reported depression symptoms, sleep habits, and experiences with antidepressant medications alongside genetic data. They used six criteria to classify participants: seasonal changes in mood, delayed sleep timing, differences in sleep schedules between workdays and days off, an evening-oriented chronotype, morning fatigue, and hypersomnia during periods of severe depression.
Participants who met at least three of these criteria were classified as having a “circadian-related depression subtype.” This group included 2,604 people, or approximately 23% of the study population. The classification was developed by the researchers to identify patients exhibiting multiple sleep- and circadian rhythm-related characteristics. It is not an officially established diagnostic category.
Within this group, 84% reported hypersomnia, 83% experienced morning fatigue, and 68% had an evening-oriented chronotype. The average age at depression onset was 18.7 years, approximately 4.5 years earlier than the 23.2-year average among participants who met fewer than three criteria.
Participants in this group also reported more severe psychological distress and more frequent suicidal thoughts. Additionally, 52% said they had experienced more than 10 episodes of depression, compared with 36% in the comparison group.
Differences were also observed in responses to medication. Participants classified as having the circadian-related subtype rated the effectiveness of commonly prescribed antidepressants—including selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs)—less favorably. They also reported more side effects.
Genetic analyses revealed that this group had higher genetic risk scores associated with major depression, anxiety, bipolar disorder, and attention-deficit/hyperactivity disorder (ADHD). These findings suggest that groups distinguished by their sleep-related characteristics may differ not only in symptoms and reported medication responses but also in their genetic profiles.
The corresponding author, Emiliana Tonini, a researcher affiliated with the University of Sydney’s Brain and Mind Centre, and her colleagues proposed that identifying patterns involving hypersomnia, morning fatigue, and other sleep- and circadian rhythm-related characteristics could help distinguish subgroups of people with depression and inform more individualized treatment strategies.
However, the researchers emphasized that further studies are needed to determine whether this classification can improve treatment outcomes in clinical practice.
The study, titled “Clinical and Genetic Correlates of a Circadian Subtype of Depression in the Australian Genetics of Depression Study,” was published in the British Journal of Psychiatry in October 2026.
Source: 하이닥 (https://news.hidoc.co.kr/news/articleView.html?idxno=69289)