Mania reduces perceived pain intensity in patients with chronic pain: preliminary evidence from retrospective archival data

Chronic REM sleep deprivation leads to manic- and OCD-related behaviors, and decreases hippocampal BDNF expression in female rats

BACKGROUND

Rapid-eye movement (REM) sleep deprivation (SD) can induce manic-like behaviors in rodents. On the other hand, lithium, as one of the oldest drugs used in neuropsychiatric disorders, is still one of the best drugs for the treatment and control of bipolar disorder. In this study, we aimed to investigate the role of chronic short-term REM SD in the induction of manic-like behaviors in female rats.

METHODS

The rats were exposed to REM SD for 14 days (6 hours/day). Lithium was intraperitoneally injected at the doses of 10, 50, and 100 mg/kg.

RESULTS

REM SD induced hyperactivity and OCD-like behavior, and decreased anxiety, depressive-like behavior, and pain subthreshold. REM SD also impaired passive avoidance memory and decreased hippocampal brain-derived neurotrophic factor (BDNF) expression level. Lithium at the doses of 50 and 100 mg/kg partly and completely abolished these effects, respectively. However, lithium (100 mg/kg) increased BDNF expression level in control and sham REM SD rats with no significant changes in behavior.

CONCLUSIONS

Chronic short-term REM SD may induce a mania-like model and lead to OCD-like behavior and irritability. In the present study, we demonstrated a putative rodent model of mania induced by chronic REM SD in female rats. We suggest that future studies should examine behavioral and mood changes following chronic REM SD in both sexes. Furthermore, the relationship between manic-like behaviors and chronic REM SD should be investigated.

Crocin (bioactive compound of Crocus sativus L.) potently restores REM sleep deprivation-induced manic- and obsessive-compulsive-like behaviors in female rats

Rapid-eye movement (REM) sleep deprivation (SD) can induce manic-like behaviors including hyperlocomotion. On the other hand, crocin (one of the main compounds of Crocus sativus L. or Saffron) may be beneficial in the improvement of mental and cognitive dysfunctions. Also, crocin can restore the deleterious effects of SD on mental and cognitive processes. In this study, we investigated the effect of REM SD on female rats' behaviors including depression- and anxiety-like behaviors, locomotion, pain perception, and obsessive-compulsive-like behavior, and also, the potential effect of crocin on REM SD effects. We used female rats because evidence on the role of REM SD in modulating psychological and behavioral functions of female (but not male) rats is limited. REM SD was induced for 14 days (6h/day), and crocin (25, 50, and 75 mg/kg) was injected intraperitoneally. Open field test, forced swim test, hot plate test, and marble burying test were used to assess rats' behaviors. The results showed REM SD-induced manic-like behavior (hyperlocomotion). Also, REM SD rats showed decreased anxiety- and depression-like behavior, pain subthreshold (the duration it takes for the rat to feel pain), and showed obsessive compulsive-like behavior. However, crocin at all doses partially or fully reversed REM SD-induced behavioral changes. In conclusion, our results suggested the possible comorbidity of OCD and REM SD-induced manic-like behavior in female rats or the potential role of REM SD in the etiology of OCD, although more studies are needed. In contrast, crocin can be a possible therapeutic choice for decreasing manic-like behaviors.

Nationwide Assessment of Chronic Pain among Hospitalized Individuals with Co-occurring Post Traumatic Stress Disorder and Substance Use Disorder in the United States

Objective: Chronic pain (CP) is independently associated with substance use disorders (SUD) and posttraumatic stress disorder (PTSD). However, little is known about factors associated with CP among patients with co-occurring PTSD and SUD. Patterns of hospital resource usage should also be explored further. Methods: Using the 2019 National Inpatient Sample (NIS), we identified 216,125 hospital discharges with co-occurring diagnoses of PTSD and SUD in 2019 and examined their association with CP. Multivariable logistic regression models were used to identify factors associated with an increased likelihood of CP in this cohort. Results: Among those with co-occurring PTSD and SUD (N = 216,125), 35,450 had associated CP, a prevalence of 164.02 cases per 1,000 discharges (95% CI [160.54, 167.52]). Individuals aged 55-64 with co-occurring PTSD and SUD were approximately 7.2 times more likely to experience CP, compared to those aged 16-24 (OR = 7.2; 95% CI [6.09, 8.60]). Being in the CP group was associated with 50% increased odds of insomnia and obesity (OR = 1.5; 95% CI [1.12, 2.03] and OR = 1.5; 95% CI [1.38, 1.55], respectively), 30% increased odds of anxiety (OR = 1.3; 95% CI [1.24, 1.38]), 20% increased odds of attention deficit disorder (ADD;OR = 1.2; 95% CI [1.12, 1.38]) and 10% increased odds of depression (OR = 1.1; 95% CI [1.01, 1.14]). Compared with females, being male was associated with slightly decreased odds of CP (OR = 0.9; 95% CI [0.84, 0.94]). Conclusions: Among hospitalized Americans with co-occurring PTSD and SUD, advanced age, being female, and the presence other mental health disorders were associated with an increased risk of CP. Providers treating co-occurring PTSD/SUD should evaluate for and consider evidence-based management of CP if present.

Cerebral processing of emotions in phantom eye pain patients: An event related potential study

Purpose

Phantom eye pain (PEP) is a major clinical problem after eye removal with no standard treatment protocol to date. As pain is a multidimensional experience associated with emotional and cognitive components, this study aimed to explore the possible neuropsychological mechanisms of PEP in a perspective of emotional cognition, in order to provide a basis for clinical treatment.

Methods

Visual oddball event-related potentials (ERPs) under different external emotional stimuli (Disgust, Fear, Sadness, Happiness, Erotica and Neutral) were tested in 12 patients and 12 healthy volunteers. Participants' affective states were measured with the Mood Disorder Questionnaire (MDQ), the Hypomania Checklist-32 (HCL-32), and the Plutchik-van Praag Depression Inventory (PVP). The amplitudes and latencies of N1, P2, N2 and P3 components were analyzed by three-way ANOVA, i.e., group (2) ​× ​emotion (6) ​× ​electrode (3). Multiple comparisons were performed using Bonferroni's test.

Results

Longer N1 latencies, increased N1 amplitudes; shorter P2 latencies under Disgust and Happiness, decreased P2 amplitudes; shorter N2 latencies under Erotica, increased N2 amplitudes were found in patients compared with controls. There was no main effect of group or interaction effect on P3 latencies and P3 amplitudes. The MDQ and HCL-32 scores were lower, and the N1 latencies under Sadness were negatively correlated with PVP scores in patients.

Conclusions

PEP patients showed reversed patterns in exogenous attention allocation and enhanced involuntary attention to emotional stimuli compared with controls. This study demonstrated cortical processing of emotions in PEP patients and could provide a basis for developing emotional intervention therapy.

Relationships between chronic pain and mood symptoms among veterans with bipolar disorder

BACKGROUND

Chronic pain is highly prevalent among individuals with mood disorders. While much is known about the relationship between pain and unipolar depression, little is known about pain experiences among people with bipolar disorder. This pilot study addresses this gap by examining pain and its relationship to mood and functioning in a sample of US military veterans with bipolar disorder.

METHODS

Qualitative interviews were conducted with 15 veterans with bipolar disorder and chronic pain who were recruited from outpatient services within a Veterans Affairs medical center.

RESULTS

Veterans reported a bidirectional relationship between pain and bipolar depression. When discussing manic episodes, individuals' experiences varied between notable reductions in pain (usually in euphoric states), increases in pain (usually in angry/irritable states), and feeling disconnected from pain. Many reported that increased activity when manic contributed to worse pain after an episode. Veterans clearly articulated how these connections negatively affected their functioning and quality of life.

LIMITATIONS

This was a small, retrospective study that included a non-random sample of veteran participants from one VA medical center. All veterans were engaged in outpatient mental health care, so the majority reported that their mood has been well-stabilized through medications and/or psychotherapy.

CONCLUSIONS

Chronic pain experiences appear to be related to depressive and manic mood states and significantly affects functioning and quality of life in Veterans with bipolar disorder. This study highlights the need to assess chronic pain among veterans with bipolar disorder, as changes in mood could have significant implications for functioning and pain management.