Seung-Chul Hong

Background and Objective In light of orexin-related gastrointestinal malignancy pathogenesis, we examined the risk of colorectal cancer in patients with type 1 narcolepsy (NT1).Methods Using the Korean National Health Insurance claims database (2010–2019), we enrolled all patients with NT1 (n=5,916) and, as controls, patients who underwent appendectomy without narcolepsy or idiopathic hypersomnia. The cohorts were matched 1:10 for sex, age, and comorbidities, and incidence rates and hazard ratios (HRs) for all malignancies and for colorectal malignancy were compared by multivariable analysis.Results The incidence of all malignancies was 664.1 (95% confidence interval, 660.6–667.6) in patients with NT1 versus 708.9 (692.4–725.7) in controls (p=0.0002), and the HR for any cancer was 0.65 (0.63–0.67) unadjusted and 0.67 (0.64–0.70) adjusted. The incidence of colorectal malignancy was 285.2 (283.3–288.1) versus 123.5 (112.4–125.9) (p<0.0001), the HR being 2.29 (2.14–2.44) unadjusted and 1.77 (1.48–2.11) adjusted.Conclusions Matched patients with NT1 showed an increased risk of colorectal malignancy but a lower risk of overall malignancy than appendectomy controls.

Objective Narcolepsy often begins in adolescence, yet diagnosis is frequently delayed. This study aimed to identify factors associated with delayed diagnosis of narcolepsy, defined as more than 1 year between symptom onset and diagnosis, focusing on age at onset, clinical symptoms, and family history.Methods We recruited 235 patients with clinically diagnosed narcolepsy from St.Vincent’s Hospital in South Korea. Participants completed an online survey assessing age at symptom onset, diagnostic timing, clinical features, and family history of sleep disorders. Patients were classified into a non-delay group (diagnosis within 1 year, n=53) and a delay group (diagnosis after 1 year, n=182). Group differences were analyzed using independent t-tests and chi-square tests.Results The mean diagnostic delay was 0.49±0.50 years in the non-delay group and 10.96±8.37 years in the delay group. The delay group had a significantly younger age at symptom onset than the non-delay group (15.13±4.88 vs. 17.89±7.91 years, p=0.002). Diagnosis in the delay group typically occurred only after marked functional impairment due to excessive daytime sleepiness. Cataplexy showed a nonsignificant trend toward earlier diagnosis, while other narcolepsy symptoms and family history were not associated with diagnostic timing.Conclusion Earlier age at onset is the strongest risk factor for delayed diagnosis of narcolepsy. Neither symptom profile nor family history reliably facilitates early recognition. Proactive screening and improved awareness among clinicians and families are needed to reduce diagnostic delay and its psychosocial burden.

Objective Cardiovascular health (CVH), assessed through Life’s Essential 8 (LE8), has been widely studied in relation to physical health outcomes. However, its association with mental health, including psychological distress, suicidal behavior, and mental health service utilization, remains underexplored. This study examined whether better CVH is associated with reduced risk of mental health problems and greater engagement with mental health services.Methods We conducted a cross-sectional analysis using data from 4,106 Korean adults aged ≥19 years from the 2021 Korea National Health and Nutrition Examination Survey. CVH was measured using LE8 and categorized into low (0–49), moderate (50–79), and high (80–100) groups. Mental health outcomes included perceived stress, depressive mood, suicidal ideation, suicide planning, suicide attempts, and mental health service utilization.Results Higher LE8 scores were significantly associated with lower stress (p=0.041) and reduced odds of suicidal ideation (p=0.001). Compared to the low CVH group, adjusted odds ratios (ORs) for stress perception were 0.748 (95% confidence interval [CI]: 0.587–0.953) in the moderate group and 0.685 (95% CI: 0.491–0.956) in the high group. For suicidal ideation, the ORs were 0.517 (95% CI: 0.329–0.813) and 0.199 (95% CI: 0.078–0.507), respectively. LE8 health behaviors, not health factors, were significantly associated with stress perception and suicidal ideation.Conclusion Better CVH is associated with lower psychological distress and suicidal behavior, with health behaviors in LE8 showing stronger associations with mental health outcomes than health factors. Further longitudinal studies are needed to confirm causality and underlying mechanisms.

Background and Objective Depression and attentional difficulties are prevalent in narcolepsy. Although depression has been noted in first-degree relatives, the impact of sleep disturbances on these self-reported symptoms remains unclear. We investigated depressive symptoms and attention-deficit/hyperactivity disorder (ADHD)-related traits in patients and their relatives, while controlling for sleep quality and sleepiness.Methods A cross-sectional study included 613 participants: narcolepsy patients (n=253), first-degree relatives (n=156), and healthy controls (n=204). We measured symptoms using the Beck Depression Inventory-II (BDI-II), Adult ADHD Self-Report Scale (ASRS), Pittsburgh Sleep Quality Index (PSQI), and Epworth Sleepiness Scale (ESS). We analyzed group differences using ANCOVA, adjusting for age, sex, body mass index, PSQI, and ESS.Results Patients exhibited significantly high unadjusted scores for depression (mean, 27.51) and attentional symptoms (mean, 11.47). After controlling for covariates, group status remained significantly associated with BDI-II total scores (F=25.03, p<0.001), with both patients and relatives reporting higher levels of depression than controls. Notably, affective-cognitive items on the BDI-II remained elevated. However, the group effect on the ASRS was no longer significant after adjustment (F=1.45, p=0.236).Conclusions Depressive symptoms were consistently elevated in both patients and first-degree relatives, even after accounting for sleep quality and daytime sleepiness, indicating a potential shared familial vulnerability. In contrast, ADHD-like symptoms appeared to be largely influenced by sleep quality and excessive daytime sleepiness, indicating they may be state-dependent.

Suhyung Kim, Young-chan Kim, Yoo Hyun Um, Tae-Won Kim, Ho-Jun Seo, Seung-Chul Hong, Sung-Hoon Yoon, Jong-Hyun Jeong. Clin Psychopharmacol Neurosci -0001;0:. https://doi.org/10.9758/cpn.25.1378

Type 1 narcolepsy (NT1), a disorder caused by the loss of hypocretin/orexin transmission, is characterized by daytime sleepiness and symptoms where Rapid Eye Movement (REM) sleep, a state normally occurring from middle to late in the night, can intermingle with wakefulness. This results in cataplexy and sleep paralysis, episodes of muscle paralysis when awake, or in the generation of dream-like hallucinations and vivid dreaming, periods of visual imagery or sensory experiences that occur while awake, notably when falling asleep (hypnagogic hallucinations) or lingering dreams with over-realistic recall. Using deep learning of nocturnal sleep polysomnography (PSG) signals (EEG, EMG and EOG) applied to sleep stage scoring, we found that NT1 shows abnormally short wake to REM sleep transitions and occurrences of abnormal sleep stages probabilities of wake, REM sleep and N1 (very light NREM) sleep abnormally co-occurs (sleep stage mixing). Interestingly, although presence of these during sleep enables NT1 diagnosis with performances similar to gold standard diagnostic procedure, the multiple sleep latency test (MSLT), the cortical localization of these dissociations remains unclear. In this work, we used electrode specific predictions of sleep stages to explore if these are global or observed at the local cortical level. Surprisingly, although sleep stage mixing was preeminent between REM sleep, N1 and wake across all electrodes, it was found to fluctuate across locations, with stronger fluctuations found in frontal and central locations, notably in the dominant (left) hemisphere. The strongest single discriminator for NT1 was N1-REM stage mixing across central electrodes (C3-C4), showing 4.3-fold higher dissociation in NT1 patients (Cohen’s d = 0.61). Analysis of sleep stage dissociations across varying time scales revealed that windows lasting several minutes were most predictive of NT1 status, aligning with the duration of clinically reported symptoms of dissociated REM sleep in narcolepsy. Local N1-W-REM sleep dissociations correlated with CSF orexin/hypocretin levels and severity as measured using MSLT. The predominance of stage mixing in frontal and central regions, areas typically associated with executive and motor control, may contribute to the partial preservation of awareness during dissociated REM phenomena. Further, self-reports of hypnagogic hallucinations correlated best with dissociations involving occipital locations, in agreement with its usual visual content. Coherence analysis was also conducted but did not reveal additional insight. These results suggest that orexin deficiency destabilizes REM sleep organization across cortical projection area contributing both to REM sleep dissociation and to abnormal state transitions observed in NT1.

Objective The visual system plays a crucial role in regulating sleep by providing cues that synchronize the circadian rhythm. Consequently, ophthalmic diseases—particularly diabetic retinopathy (DMR), age-related macular degeneration (AMD), epiretinal membrane (EM), and glaucoma—may influence sleep duration through circadian disruption and disease-related psychological stress. However, large-scale studies examining the relationship between these conditions and sleep duration remain limited. This study investigated these associations in a nationwide, population-based sample.Methods This cross-sectional study analyzed data from the 2019 and 2020 the Korea National Health and Nutrition Examination Survey. Ophthalmic diseases were diagnosed through fundoscopy, and sleep duration on weekdays and weekends was self-reported. The study included 8,395 participants aged 40 years or older who underwent fundoscopy. Statistical models were adjusted for demographic and clinical covariates, including age, sex, body mass index, and comorbidities.Results Patients with DMR and EM had significantly reduced sleep duration, with reductions of 0.3 hours to 0.5 hours on weekdays and weekends compared to individuals without these conditions. No significant differences in sleep duration were observed for AMD or glaucoma. After covariate adjustment, the associations between shorter sleep duration and DMR or EM remained significant.Conclusion This nationwide population-based study using fundus photography revealed that DMR and EM are significantly associated with reduced sleep duration, while AMD and glaucoma are not. These findings suggest a differential sleep impact by disease type and support the need for targeted evaluation and management of sleep in patients with ophthalmic diseases. Further research is warranted to clarify underlying mechanisms and guide public health strategies.

Young-Chan Kim, Kyungdo Han, Suhyung Kim, Yoo Hyun Um, Tae-Won Kim, Ho Jun Seo, Seung-Chul Hong, Jong-Hyun Jeong. Clin Psychopharmacol Neurosci 2025;23:476-87. https://doi.org/10.9758/cpn.25.1310

Purpose Narcolepsy diagnosis relies on polysomnography (PSG) and the Multiple Sleep Latency Test (MSLT), though concerns remain regarding their diagnostic accuracy and reliability. Nocturnal sleep-onset rapid eye movement periods (SOREMPs) are a known feature of narcolepsy. This study investigated the clinical significance of nocturnal SOREMP in narcolepsy diagnosis and its association with test–retest reliability. Methods We retrospectively reviewed 109 patients who underwent at least two MSLTs. Patients were categorized into nocturnal SOREMP (n = 40) and non-nocturnal SOREMP (n = 69) groups based on PSG findings. Only MSLT-identified SOREMPs were used for diagnosis. Group comparisons and follow-up changes were analyzed using t-tests, chi-square tests, or Wilcoxon signed-rank tests. Results The nocturnal SOREMP group had more SOREMPs (3.50 vs. 2.23), shorter mean sleep latency (1.99 vs. 4.77), and higher initial narcolepsy diagnosis rates (92.5% vs. 63.8%). Diagnostic stability was significantly higher in the nocturnal group (90.0% vs. 50.7%). Among narcolepsy type 2 (NT2) patients, those with nocturnal SOREMP showed complete diagnostic retention (100%), whereas only 27.3% of those without nocturnal SOREMP did. In a subgroup analysis, patients who had a nocturnal SOREMP on at least one of the two PSGs exhibited significantly higher diagnostic stability (93.9%) than those without nocturnal SOREMP on either test (50.0%). Similarly, NT2 retention was 100% in the former versus 16.7% in the latter. Conclusions Nocturnal SOREMP may serve as a specific marker for narcolepsy, suggesting potential utility in supporting diagnostic consistency. Its presence appears to be associated with improved diagnostic reliability, particularly in NT2.