Pregabalin withdrawal in patients without psychiatric disorders taking a regular dose of pregabalin: A case series and literature review

Pregabalin is a drug that can cause psychiatric symptoms via pregabalin withdrawal. Prior reports on pregabalin withdrawal have mainly focused on cases with pregabalin dependence or abuse, and little attention has been paid to patients who are prescribed regular doses of pregabalin. Herein, we report three cases of pregabalin withdrawal in patients without psychiatric disorders, taking regular doses of pregabalin, who developed psychiatric symptoms such as insomnia and anxiety after abrupt discontinuation of pregabalin. In addition, we conducted a systematic review of six case reports (previous studies) of pregabalin withdrawal under regular doses of pregabalin. Among the six cases, three patients had no comorbid mental or substance use disorders, the dose of pregabalin ranged from 150 to 600 mg/d, and the duration of pregabalin use ranged from a few weeks to many years. Of these six cases of pregabalin withdrawal, five had psychopathological symptoms, three had vegetative symptoms, and three had neurologic and physical complications. We concluded that since pregabalin withdrawal can occur even with regular doses and short-term use, clinicians must carefully reduce pregabalin doses when reducing or discontinuing treatment, paying close attention to withdrawal symptoms. Our case series sheds light on the scant evidence from previous research on physical dependence in patients who are taking regular doses of pregabalin. Furthermore, our cases were also valuable in demonstrating that pregabalin withdrawal can occur even after a relatively short period of 2 months

Decreased activity in the reward network of chronic insomnia patients

In modern society, many people have insomnia. Chronic insomnia has been noted as a risk factor for depression. However, there are few functional imaging studies of the brain on affective functions in chronic insomnia. This study aimed to investigate brain activities induced by emotional stimuli in chronic insomnia patients. Fifteen patients with primary insomnia and 30 age and gender matched healthy controls participated in this study. Both groups were presented images of fearful, happy, and neutral expressions consciously and non-consciously while undergoing MRI to compare the activity in regions of the brain responsible for emotions. Conscious presentation of the Happy-Neutral contrast showed significantly lower activation in the right orbitofrontal cortex of patients compared to healthy controls. The Happy-Neutral contrast presented in a non-conscious manner resulted in significantly lower activation of the ventral striatum, right insula, putamen, orbitofrontal cortex and ventral tegmental area in patients compared to healthy controls. Our findings revealed that responsiveness to positive emotional stimuli were decreased in insomniac patients. Specifically, brain networks associated with rewards and processing positive emotions showed decreased responsiveness to happy emotions especially for non-conscious image. The magnitude of activity in these areas also correlated with severity of insomnia, even after controlling for depression scale scores. These findings suggest that insomnia induces an affective functional disorder through an underlying mechanism of decreased sensitivity in the regions of the brain responsible for emotions and rewards to positive emotional stimuli

Development and validation of the Japanese version of the Bedtime Procrastination Scale (BPS-J)

Abstract Background The average sleep duration of Japanese people is shorter than that of people from other countries, and bedtime procrastination is suspected to be one of the factors contributing to this issue. This study aimed to develop and validate the Japanese version of the Bedtime Procrastination Scale (BPS-J). Methods The BPS-J was developed through procedures including the translation and back-translation of the scale, cognitive interviews with 100 participants who reported having experiences of being diagnosed with insufficient sleep syndrome (ISS) or receiving treatment for ISS using open-ended online questionnaires, and expert checking. To investigate the scale’s validity and reliability, an online survey was conducted with daytime workers aged 20 − 65 years without a history of sleep disorders other than ISS. Half the participants were retested using the same survey after 14 days. Participants’ responses to the Brief Self-Control Scale (BSCS), General Procrastination Scale (GPS), and Munich ChronoType Questionnaire (MCTQ), and data on sleep-related variables such as sleep duration on workdays and the days per week of fatigue or sleep loss, sex, and age, were collected. Results We analyzed data from 574 participants to assess scale validity. We then analyzed data from 280 participants to determine test–retest reliability. Confirmatory factor analyses revealed that the two-factor model without Item 2 was most suitable for the BPS-J, unlike other language versions. Regardless of the full-item model or the model with Item 2 eliminated, sufficient reliability and significant correlations with the BSCS, GPS, MCTQ, and sleep-related variables such as sleep duration per night on work days, days per week of feeling fatigued, and days per week of sleep loss were observed. Logistic and linear regressions showed that the relationships between the BPS-J, sleep-related variables, and MCTQ were maintained after adjusting for sex and age. Conclusion The BPS-J had sufficient validity and reliability. Further, eliminating Item 2 from the original version of the BPS strengthened the ability to survey Japanese daytime workers