Discrimination, cognitive styles, and their associations with adolescents' mental and physical health

This study is based on the hopelessness theory of depression and previous research on perceived everyday discrimination (PED) and both depressive symptoms and Interleukin-6 (an inflammatory cytokine; IL-6) in adolescents. The purpose of this study is to examine the negative attribution, self, and consequence cognitive styles (CSs) proposed in the hopelessness theory as a possible mechanism underlying the association between PED and inflammation in adolescents and expand our understanding of the comorbidities between depressive symptoms and systemic inflammation (IL-6). This cross-sectional study featured a sample of 102 adolescents aged 13-16 (M = 14.10, SD = 0.52) who identified as White (47.5%), Black (41.4%), Mixed Race (7.1%), Latino (2%), and other (2%). Data analysis was conducted using PROCESS to compute regressions and effects between PED, negative CSs, depressive symptoms, and Interleukin-6. Results showed that negative attribution CS is the only negative CS associated with PED, depressive symptoms, and IL-6. Negative attribution CS is also the only negative CS of the three negative CSs that mediates both the association between PED and depressive symptoms and PED and IL-6 in our adolescent sample. Overall, these results indicate that individual negative CSs proposed in the hopelessness theory impact adolescents' physical and mental outcomes differently, which can inform targeted treatments. Nurses should provide cognitive-based interventions and promote societal-level change to reduce the experience and impact of PED on the mental and physical health of their adolescent patients.

Effect of detoxification on N3 sleep correlates with brain functional but not structural changes in alcohol use disorder

BACKGROUND

Sleep disturbances are very common in alcohol use disorder (AUD) and contribute to relapse. Detoxification appears to have limited effects on sleep problems. However, inter-individual differences and related brain mechanisms have not been closely examined.

METHODS

We examined N3 sleep and the associated brain functional and structural changes in 30 AUD patients (9 Females, mean age: 42 years) undergoing a 3-week inpatient detoxification. Patients' N3 sleep, resting state functional connectivity (RSFC), grey matter volume (GMV) and negative mood were measured on week 1 and week 3.

RESULTS

AUD patients did not show significant N3 sleep recovery after 3-weeks of detoxification. However, we observed large variability among AUD patients. Inter-individual variations in N3 increases were associated with increases in midline default mode network (DMN) RSFC but not with GMV using a whole-brain approach. Exploratory analyses revealed significant sex by detoxification effects on N3 sleep such that AUD females showed greater N3 increases than AUD males. Further, N3 increases fully mediated the effect of mood improvement on DMN RSFC increases.

CONCLUSIONS

We show a significant relationship between N3 and DMN functional changes in AUD over time/abstinence. The current findings may have clinical implications for monitoring brain recovery in AUD using daily sleep measures, which might help guide individualized treatments. Future investigations on sex differences with a larger sample and with longitudinal data for a longer period of abstinence are needed.

Dopamine D1 and D2 receptors are distinctly associated with rest-activity rhythms and drug reward

BACKGROUND

Certain components of rest-activity rhythms such as greater eveningness (delayed phase), physical inactivity (blunted amplitude) and shift work (irregularity) are associated with increased risk for drug use. Dopaminergic (DA) signaling has been hypothesized to mediate the associations, though clinical evidence is lacking.

METHODS

We examined associations between rhythm components and striatal D1 (D1R) and D2/3 receptor (D2/3R) availability in 32 healthy adults (12 female, age: 42.40±12.22) and its relationship to drug reward. Rest-activity rhythms were assessed by one-week actigraphy combined with self-reports. [11C]NNC112 and [11C]raclopride Positron Emission Tomography (PET) scans were conducted to measure D1R and D2/3R availability, respectively. Additionally, self-reported drug-rewarding effects of 60 mg oral methylphenidate were assessed.

RESULTS

We found that delayed rhythm was associated with higher D1R availability in caudate, which was not attributable to sleep loss or 'social jet lag', whereas physical inactivity was associated with higher D2/3R availability in nucleus accumbens (NAc). Delayed rest-activity rhythm, higher caudate D1R and NAc D2/3R availability were associated with greater sensitivity to the rewarding effects of methylphenidate.

CONCLUSION

These findings reveal specific components of rest-activity rhythms associated with striatal D1R, D2/3R availability and drug-rewarding effects. Personalized interventions that target rest-activity rhythms may help prevent and treat substance use disorders.

TRIAL REGISTRATION

ClinicalTrials.gov: NCT03190954FUNDING. This work was accomplished with support from the National Institute on Alcohol Abuse and Alcoholism (ZIAAA000550).

Ketogenic diet reduces alcohol withdrawal symptoms in humans and alcohol intake in rodents

Individuals with alcohol use disorder (AUD) show elevated brain metabolism of acetate at the expense of glucose. We hypothesized that a shift in energy substrates during withdrawal may contribute to withdrawal severity and neurotoxicity in AUD and that a ketogenic diet (KD) may mitigate these effects. We found that inpatients with AUD randomized to receive KD (n = 19) required fewer benzodiazepines during the first week of detoxification, in comparison to those receiving a standard American (SA) diet (n = 14). Over a 3-week treatment, KD compared to SA showed lower "wanting" and increased dorsal anterior cingulate cortex (dACC) reactivity to alcohol cues and altered dACC bioenergetics (i.e., elevated ketones and glutamate and lower neuroinflammatory markers). In a rat model of alcohol dependence, a history of KD reduced alcohol consumption. We provide clinical and preclinical evidence for beneficial effects of KD on managing alcohol withdrawal and on reducing alcohol drinking.