State or trait? Auditory event-related potentials in adolescents with current and remitted major depression

The P3 ERP in Relation to General Versus Specific Psychopathology in Early Childhood

There is considerable covariation between externalizing and internalizing problems across the lifespan. Partitioning general and specific psychopathology is crucial to identify (a) processes that confer specific risk for externalizing versus internalizing problems and (b) transdiagnostic processes that confer risk for the covariation between externalizing and internalizing problems. The oddball P3 event-related potential (ERP) component, thought to reflect attentional orienting, has been widely examined in relation to psychopathology. However, prior studies have not examined the P3-or other aspects of neural functioning-in relation to general versus specific psychopathology in children. The present study examined whether children's (N = 124, ages 3-7 years) P3 amplitudes were associated with general versus specific psychopathology. Children's electroencephalography data were recorded during an oddball task. Parents rated their children's externalizing and internalizing problems. Using bifactor models to partition variance in parents' ratings of children's psychopathology symptoms, we examined children's P3 amplitudes in relation to three latent factors: (1) the general factor of psychopathology-the covariation of externalizing and internalizing psychopathology, (2) unique externalizing problems-the variance in externalizing problems after controlling for the general factor, and (3) unique internalizing problems. Results indicated that smaller P3 amplitudes were associated with unique externalizing problems at ages 3-5, and with general psychopathology at ages 6-7. Findings suggest that smaller P3 amplitudes may be associated with externalizing problems from a very young age. Moreover, there may be a developmental shift in the functional significance of the P3 in relation to general and specific psychopathology in childhood.

Changes in the TMS-evoked potential N100 in the dorsolateral prefrontal cortex as a function of depression severity in adolescents

Studies using transcranial magnetic stimulation with simultaneous electroencephalography (TMS-EEG) revealed an imbalance between cortical excitation and inhibition (E/I) in the dorsolateral prefrontal cortex (DLPFC) in depression. As adolescence is a developmental period with an increase in depression prevalence and profound neural changes, it is crucial to study the relationship between depression and cortical excitability in adolescence. We aimed to investigate the cortical excitability of the DLPFC in adolescents with depression and a dependency of the TMS-evoked potential N100 on the depression severity. 36 clinical patients (12–18 years of age; 21 females) with a major depressive episode were assessed twice in a longitudinal design: shortly after admission (T0) and after six weeks of intervention (T1). GABA-B-mediated cortical inhibition in the left and right DLPFC, as assessed by the N100, was recorded with EEG. Significantly higher depression scores were reported at T0 compared to T1 (p < 0.001). N100 amplitudes were significantly increased (i.e., more negative) at T0 compared to T1 (p = 0.03). No significant hemispheric difference was found in the N100 component. The correlation between the difference in depression severity and the difference in N100 amplitudes (T0–T1) obtained during stimulation of the left DLPFC did not remain significant after correction for testing in both hemispheres. Higher N100 amplitudes during a state of greater depression severity are suggestive of an E/I imbalance in the DLPFC in adolescents with an acute depressive episode. The N100 reduction potentially reflects a normalization of DLPFC over inhibition in association with decreased depressive symptomatology, indicating severity dependency.

Auditory event-related potentials in separating patients with depressive disorders and non-depressed controls: A narrative review

This narrative review brings together the findings regarding the differences in the auditory event-related potentials (ERPs) between patients with depressive disorder and non-depressed control subjects. These studies' results can inform us of the possible alterations in sensory-cognitive processing in depressive disorders and the potential of using these ERPs in clinical applications. Auditory P3, mismatch negativity (MMN) and loudness dependence of auditory evoked potentials (LDAEP) were the subjects of the investigation. A search in PubMed yielded 84 studies. The findings of the reviewed studies were not highly consistent, but some patterns could be identified. For auditory P3b, the common findings were attenuated amplitude and prolonged latency among depressed patients. Regarding auditory MMN, especially the amplitude of duration deviance MMN was commonly attenuated, and the amplitude of frequency deviance MMN was increased in depressed patients. In LDAEP studies, generally, no differences between depressed patients and non-depressed controls were reported, although some group differences concerning specific depression subtypes were found. This review posits that future research should investigate whether certain stimulus conditions are particularly efficient at separating depressed and non-depressed participant groups. Future studies should contrast responses in different subpopulations of depressed patients, as well as different clinical groups (e.g., depressive disorder and anxiety disorder patients), to investigate the specificity of the auditory ERP alterations for depressive disorders.

Blunted Flanker P300 Demonstrates Specificity to Depressive Symptoms in Females during Adolescence

Recent research suggests that depressive disorders in adults are characterized by reductions in flanker P300 amplitude, and that a reduced flanker P300 may also predict worst depressive trajectories over time. The current study extended this work to adolescence-and to evaluate the specificity of the relationship between flanker P300 to depressive symptoms versus anxiety symptoms, and whether the association between flanker P300 and depressive symptoms was moderated by biological sex. To this end, P300 amplitude, depression, anxiety, and sex were assessed in a large sample of 619 adolescents aged 11 to 14. Participants completed a speeded response flanker task while EEG was recorded, as well as self-reported measures of current depression and anxiety symptoms. Reduced P300 amplitude was related to both heightened depression and anxiety symptoms in zero-order correlations. Regression-based analyses suggest that reduced P300 was uniquely related to depressive symptoms. Furthermore, this negative association between P300 and depression was apparent in female adolescents, but not male adolescents. In sum, the current study suggests that flanker P300 amplitude may potentially serve as a neural marker specific to depression in females during adolescence.

Active and Passive Attentional Processing in Adolescent Suicide Attempters: An Event-Related Potential Study

INTRODUCTION

Suicide is the second leading cause of death among adolescents. Suicidal behavior is associated with impairments in attention. Attention can be directed toward relevant events in the environment either actively, under voluntary control, or passively, by external salient events. The extent to which the risk for suicidal behavior affects active and passive attention is largely unknown.

METHODS

Event-related potentials (ERPs) were recorded while 14 adolescents with acute suicidal behavior and 14 healthy controls performed an auditory 3-stimulus oddball task. The task consisted of standard (80%), target (10%), and novel (10%) stimuli. The participants were instructed to press a button upon presentation of the target. The novel stimuli were unexpected and irrelevant to the target detection task.

RESULTS

Accuracy of target detection was slightly but significantly reduced in the suicidal group. There were no significant differences in the amplitude of the target-N2 or -P3b between groups. There was a slight, but nonsignificant, increase in the amplitude of the novel-N2 and -P3 in the suicidal group.

CONCLUSIONS

This is the first study to explore both passive and controlled aspects of attention using ERPs in adolescents with acute suicidal behavior. Although there were no significant ERP group differences, this is an important step in identifying objective markers of suicide risk among adolescents.

Neurophysiological markers of attention distinguish bipolar disorder and unipolar depression

BACKGROUND

Attentional deficits are common in both symptomatic and symptom-remitted patients with bipolar disorder (BP) and major depressive disorder (MDD). However, whether the level of neurocognitive impairment in attentional processing is different between these two disorders, or not, is still unclear. Thus, we investigated the P300 event-related potential component as a biomarker of cognitive dysfunction to differentiate BP and MDD.

METHODS

Twenty-three age and gender matched BP, 20 MDD and 23 healthy controls (HC) were part of a discovery cohort to identify neurophysiological differences between groups and build a classification model of these disorders. The replication of this model was then tested in an independent second cohort of 17 BP, 19 MDD and 19 HC. All participants were symptom-remitted for at least two weeks. We compared neural responses to target stimuli during an auditory oddball task, computing peak amplitude and latency of the P300 component extracted from the midline centro-parietal electrode.

RESULTS

BP had significantly smaller P300 amplitudes compared to both MDD and HC, whereas there were no differences between MDD and HC. The differences between groups were replicated in the second cohort, however the accuracy level of the classification model was only 53.5%.

LIMITATIONS

Small sample sizes may have led to low accuracy levels of the classification model.

CONCLUSION

Specific neural mechanisms of attention and context updating seem not to recover with symptom remission in BP. These findings contribute to the detection of a potential electrophysiological marker for BP, which may allow its differentiation from unipolar major depressive disorder.