The relationships between insomnia, nightmares, and dreams: A systematic review.

Insomnia and nightmares are both prevalent and debilitating sleep difficulties. The present systematic review aims to document the relationships between insomnia and nightmares in individuals without a concomitant psychopathology. The relationships between insomnia and dreams are also addressed. PsycINFO and Medline were searched for papers published in English or French from 1970 to March 2023. Sixty-seven articles were included for review. Most results support positive relationships between insomnia variables and nightmare variables in individuals with insomnia, individuals with nightmares, the general population, students, children and older adults, and military personnel and veterans. These positive relationships were also apparent in the context of the COVID-19 pandemic. Some psychological interventions, such as Imagery Rehearsal Therapy, might be effective in alleviating both nightmares and insomnia symptoms. Regarding the relationships between insomnia and dreams, compared with controls, the dreams of individuals with insomnia are characterized by more negative contents and affects. The results show that insomnia and nightmares are connected and may be mutually aggravating. A model is proposed to explain how insomnia might increase the likelihood of experiencing nightmares, and how nightmares can in turn lead to sleep loss and nonrestorative sleep.

Neurofeedback for insomnia: Current state of research.

BACKGROUND: Chronic insomnia affects about 6%-13% of the Canadian population. Although treatments already exist, they each have their own issues. Neurofeedback is a neuromodulation technique that specifically targets abnormal brain activity and is gaining attention as a possible insomnia treatment. AIM: To review the latest studies pertaining to the use of neurofeedback in the treatment of insomnia. METHODS: In this non-systematic review, only experimental studies assessing the effects of neurofeedback on patients with insomnia were targeted across four bibliographic databases. RESULTS: A total of 12 studies were retained. All neurofeedback studies included in this study showed a clear improvement of subjective sleep. However, data concerning objective improvement are contradictory. Most studies regarding surface and z-score neurofeedback show that neurofeedback targeting the sensorimotor rhythm in the sensorimotor cortex may help improve subjective sleep. A placebo effect seems also to be present in some studies. Several limitations were present in each study. CONCLUSION: While studies concerning neurofeedback as a treatment for insomnia are encouraging, many methodological barriers remain to be resolved to prove its efficacy unequivocally. More studies using robust design parameters, as well as the replication of existing studies, are necessary to support neurofeedback as an effective treatment for insomnia.