Depression and Anxiety Subgroups Across Alcohol Use Disorder and Substance Use in a National Epidemiologic Study

Abstract

Objective: The high prevalence of alcohol/substance use among individuals with psychiatric disorders elucidates the import of investigations into associations between types and severity of psychiatric symptoms and alcohol/substance use. This study examined the likelihood of alcohol use disorder and substance use among individuals with varying depression and anxiety symptoms and severity thereof. Differences across sex were also examined.

Methods: Using data from the National Epidemiological Survey on Alcohol and Related Conditions, a nationally representative sample from the United States (N?=?43,093), separate logistic regressions estimated the odds of lifetime alcohol use disorder, depressant, stimulant, hallucinogen, and comorbid substance use across psychiatric symptom clusters controlling for age, sex, and ethnicity.

Results: Symptom severity was a more important correlate of alcohol use disorder and substance use than symptom type. In particular, the odds ratio of lifetime use of depressants, stimulants, hallucinogens, or any combination of these types of substances were higher for individuals with either severe depression or severe depression and anxiety relative to a healthy control. Moreover, the odds of having a diagnosis of lifetime alcohol use disorder were higher for individuals with severe symptoms of depression, anxiety, and both depression and anxiety, relative to healthy individuals. Those with mild depression were more likely to engage in substance use than individuals with anxiety alone. Patterns of association among males and females were highly consistent.

Conclusions: The findings highlight an enhanced risk of alcohol and substance use among individuals with severe depression and/or anxiety symptoms above what is seen among individuals with less severe symptomatology. In addition, this study shows a unique risk posed by the presence of depression on substance use. This study offers a framework for future studies to examine the causal mechanisms explaining the connection between psychiatric symptoms and alcohol/substance use.     

Investigating functional changes in the brain to intermittently induced auditory illusions and its relevance to chronic tinnitus

Several studies have demonstrated the neural correlates of chronic tinnitus. However, we still do not understand what happens in the acute phase. Past studies have established Zwicker tone (ZT) illusions as a good human model for acute tinnitus. ZT illusions are perceived following the presentation of a notched noise stimulus, that is, broadband noise with a narrow band‐stop filter (notch). In the current study, we compared the neural correlates of the reliable perception of a ZT illusion to that which is not. We observed changes in evoked and total theta power in wide‐spread regions of the brain particularly in the temporal‐parietal junction, pregenual anterior cingulate cortex/ventromedial prefrontal cortex (pgACC/vmPFC), parahippocampus during perception of the ZT illusion. Furthermore, we observe that increased theta power significantly predicts a gradual positive change in the intensity of the ZT illusion. Such changes may suggest a malfunction of the sensory gating system that enables habituation to redundant stimuli and suppresses hyperactivity. It could also suggest a successful retrieval of the memory of the missing frequencies, resulting in their conscious perception indicating the role of higher‐order processing in the mechanism of action of ZT illusions. To establish a more concrete relationship between ZT illusion and chronic tinnitus, future longitudinal studies following up a much larger sample of participants who reliably perceive a ZT illusion to see if they develop tinnitus at a later stage is essential. This could inform us if the ZT illusion may be a precursor to chronic tinnitus.     

Comparative analysis of different methods used for molecular characterization of Burkholderia cepacia complex isolated from noncystic fibrosis conditions

PurposeBurkholderia is a Gram-negative opportunistic bacterium capable of causing severe nosocomial infections. The aim of this study was to characterize Burkholderia cepacia complex and to compare different molecular methods used in its characterization.MethodsIn this study, 45 isolates of Burkholderia cepacia complex (Bcc) isolated from clinical cases were subjected to RAPD (Random amplified polymorphic DNA), recA-RFLP (Restriction fragment length polymorphism), 16SrDNA-RFLP, whole-cell protein analysis, recA DNA sequencing and biofilm assay.ResultsOf the 45 isolates tested, 97.7% were sensitive to ceftazidime, 82.2% were sensitive to Cotrimoxazole, 73.3% were sensitive to meropenem, 55.5% were sensitive to minocycline and 42.2% were sensitive to levofloxacin. Majority of the isolates harbored all the tested virulence genes except bpeA and cblA. The RAPD generated 11 groups (R1-R11), recA-RFLP 10 groups (A1-A10), 16SrRNA-RFLP 5 groups (S1–S5) and SDS-PAGE (Sodium Dodecyl Sulphate-Polyacrylamide gel electrophoresis) whole cell protein analysis revealed 12 groups (C1–C12). recA sequencing revealed that most of the isolates belonging to the genomovar III Burkholderia cenocepacia. Though all the methods are found to be efficient in differentiating Burkholderia spp., recA-RFLP was highly discriminatory at 96% similarity value. The study also identified a new strain Burkholderia pseudomultivorans for the first time in the country. Further, recA sequencing could identify the strains to species level. Majority of the multidrug-resistant strains also showed moderate to strong biofilm-forming ability, which further contributes to the virulence characteristics of the pathogens.ConclusionsThe study highlights the importance of combination of molecular methods to characterize Burkholderia cepacia complex. Molecular typing of these human pathogens yields important information for the clinicians in order to initiate the most appropriate therapy in the case of severe infections and to implement preventive measures for the effective control of transmission of Burkholderia spp.     

Bacteroides fragilis concealed in an infant with Escherichia coli meningitis

Anaerobic meningitis in infants is rare, therefore a high index of clinical suspicion is essential as routine methods for processing cerebrospinal fluid (CSF) do not detect anaerobes and specific antimicrobial therapy is required. We present an infant with Escherichia coli meningitis where treatment‐resistance developed in association with culture negative purulent CSF. These features should have alerted us to the presence of anaerobes, prompting a search for the causes of polymicrobial meningitis in infants.     

Mitochondrial activity in the frontal cortex area 8 and angular gyrus in Parkinson's disease and Parkinson's disease with dementia

Altered mitochondrial function is characteristic in the substantia nigra in Parkinson's disease (PD). Information about mitochondria in other brain regions such as the cerebral cortex is conflicting mainly because most studies have not contemplated the possibility of variable involvement depending on the region, stage of disease progression and clinical symptoms such as the presence or absence of dementia. RT‐qPCR of 18 nuclear mRNAs encoding subunits of mitochondrial complexes and 12 mRNAs encoding energy metabolism‐related enzymes; western blotting of mitochondrial proteins; and analysis of enzymatic activities of complexes I, II, II, IV and V of the respiratory chain were assessed in frontal cortex area 8 and the angular gyrus of middle‐aged individuals (MA), and those with incidental PD (iPD), long‐lasting PD with parkinsonism without dementia (PD) and long‐lasting PD with dementia (PDD). Up‐regulation of several genes was found in frontal cortex area 8 in PD when compared with MA and in the angular gyrus in iPD when compared with MA. Marked down‐regulation of genes encoding mitochondrial subunits and energy metabolism‐related enzymes occurs in frontal cortex but only of genes coding for energy metabolism‐related enzymes in the angular gyrus in PDD. Significant decrease in the protein expression levels of several mitochondrial subunits encoded by these genes occurs in frontal cortex area 8 and angular gyrus in PDD. Moreover, expression of MT‐ND1 which is encoded by mitochondrial DNA is also reduced in PDD. Reduced enzymatic activity of complex III in frontal cortex area 8 and angular gyrus is observed in PD, but dramatic reduction in the activity of complexes I, II, II and IV in both regions characterizes PDD. Dementia in the context of PD is linked to region‐specific deregulation of genomic genes encoding subunits of mitochondrial complexes and to marked reduction in the activity of mitochondrial complexes I, II, III and IV.