Profile of sleep disturbances in patients with recurrent depressive disorder or bipolar affective disorder in a tertiary sleep disorders service

Abstract

Bidirectional relationship between sleep disturbances and affective disorders is increasingly recognised, but its underlying mechanisms are far from clear, and there is a scarcity of studies that report on sleep disturbances in recurrent depressive disorder (RDD) and bipolar affective disorder (BPAD). To address this, we conducted a retrospective study of polysomnographic and clinical records of patients presenting to a tertiary sleep disorders clinic with affective disorders. Sixty-three BPAD patients (32 female; mean age ± S.D.: 41.8 ± 12.4 years) and 126 age- and gender-matched RDD patients (62 female; 41.5 ± 12.8) were studied. Whilst no significant differences were observed in sleep macrostructure parameters between BPAD and RDD patients, major differences were observed in comorbid sleep and physical disorders, both of which were higher in BPAD patients. Two most prevalent sleep disorders, namely obstructive sleep apnoea (OSA) (BPAD 50.8.0% vs RDD 29.3%, P = 0.006) and insomnia (BPAD 34.9% vs RDD 15.0%, P = 0.005) were found to be strongly linked with BPAD. In summary, in our tertiary sleep clinic cohort, no overt differences in the sleep macrostructure between BPAD and RDD patients were demonstrated. However, OSA and insomnia, two most prevalent sleep disorders, were found significantly more prevalent in patients with BPAD, by comparison to RDD patients. Also, BPAD patients presented with significantly more severe OSA, and with higher overall physical co-morbidity. Thus, our findings suggest an unmet/hidden need for earlier diagnosis of those with BPAD.

Dreaming Characteristics in Non-Rapid Eye Movement Parasomnia and Idiopathic Rapid Eye Movement Sleep Behaviour Disorder: Similarities and Differences

“…Overall, we propose that our results support the feasibility of automatic differential diagnosis of dream narratives based on word-by-word speech graph analysis ( Figure 2 ). 36 Interestingly, it has been shown that schizophrenia and bipolar affective disorder patients, both previously associated with significant changes in sleep architecture, 21 , 45 respond in a reciprocal manner to the dream-report task. For instance, the former were reported to sustain flattened speech, whereas the latter responded to increased confabulation.…”

“… 15 , 16 More specifically, sleep parasomnias, such as NREM parasomnia (NREMP) 5 , 9 , 17 , 18 and (idiopathic) REM sleep Behavior Disorder (iRBD), 19 , 20 exemplify a rare opportunity to gain a direct insight into dream activity and mentation. 1 , 6 , 16 , 21 …”

“…15,16 More specifically, sleep parasomnias, such as NREM parasomnia (NREMP) 5,9,17,18 and (idiopathic) REM sleep Behavior Disorder (iRBD), 19,20 exemplify a rare opportunity to gain a direct insight into dream activity and mentation. 1,6,16,21 Parasomnias are associated with distinct sleep states/stages, but they can also occur during sleep wake transitions. 6 RBD, characterized by loss of typical REM-like atonia and abnormal behaviors during REM sleep, may indicate an early stage of neurodegeneration linked with alpha-synucleinopathies.…”

“…9,13 Understanding how basic physiological components of sleep may contribute to the genesis of dreams will be pivotal for future translational clinical purposes. 1,7,21,32 However, it is widely accepted that oneiric research is significantly limited by an inaccessible nature of dreams, where any insight on intrinsic dream activity depends on retrospective recall by dreamers. 6,33 These, as of yet non-circumvented, methodological problems effectively mean that oneiric research commonly incorporates data that has unknown quantity of distortions in recall, along with omissions caused by reprocessing of memory for the event.…”