Denisa Jasova

Depression, traumatic stress and interleukin-6

BACKGROUND Recent evidence indicates that various types of interactions between nervous and immune system are important in pathogenesis of depression. These findings show that a significant role in developing depression play pro-inflammatory cytokines that may mediate its psychological, and neurobiological manifestations. Great importance among these cytokine molecules plays interleukin-6 (IL-6). There is growing evidence that this inflammatory process related to depression may be influenced by psychological stress as well as organic inflammatory conditions. These findings suggest that specific influences related to traumatic stress and dissociation could be found in close relationship to increased level of cytokine IL-6. METHODS In the present study we have performed psychometric measurement of depression (BDI-II), traumatic stress symptoms (TSC-40) and dissociation (DES, SDQ-20), and immunochemical measure of serum IL-6 in 40 inpatients with unipolar depression (mean age 42.3+/-6.8). RESULTS The results show that IL-6 is significantly correlated to BDI-II (Spearman R=0.47, p<0.01), TSC-40 (Spearman R=0.32, p<0.05), SDQ-20 (Spearman R=0.34, p<0.05) but not to DES (Spearman R=0.25, p=0.11). CONCLUSION The findings of the present study indicate that increased level of IL-6 in depression could be directly related to symptoms of traumatic stress and somatoform dissociation.

Dissociation, cognitive conflict and nonlinear patterns of heart rate dynamics in patients with unipolar depression.

Recent findings in cognitive neuroscience indicate that activation of anterior cingulate cortex (ACC) is related to detecting cognitive conflict. Conflict related ACC activation elicits responses in central autonomic network which can be assessed by psychophysiological measures such as heart rate variability (i.e. beat to beat R-R intervals--RRI). Recent findings in neuroscience also suggest that cognitive conflict is related to specific nonlinear chaotic changes of the signal generated by the neural systems. The present study used Stroop word-colour test as an experimental approach to the study of cognitive conflict in connection with RRI measurement, psychometric measurement of dissociation (DES) and calculation of largest Lyapunov exponents in nonlinear data analysis of RRI time series in 40 patients with unipolar depression and 35 healthy controls. Significant correlation 0.58 (p<0.01) between largest Lyapunov exponents and DES found in depressive patients indicate that cognitive conflict related neural interference during conflicting Stroop task is closely related to dissociative processes. These results present first supportive evidence that degree of chaos could be related to dissociation.

Subclinical epileptiform process in patients with unipolar depression and its indirect psychophysiological manifestations.

Background According to recent clinical findings epileptiform activity in temporolimbic structures may cause depressive and other psychiatric symptoms that may occur independently of any seizure in patients history. In addition in these patients subclinical seizure-like activity with indirect clinical manifestations likely may occur in a form of various forms of cognitive, affective, memory, sensory, behavioral and somatic symptoms (the so-called complex partial seizure-like symptoms). A typical characteristic of epileptiform changes is increased neural synchrony related to spreading of epileptiform activity between hemispheres even in subclinical conditions i.e. without seizures. These findings suggest a hypothesis that measures reflecting a level of synchronization and information transfer between hemispheres could reflect spreading of epileptiform activity and might be related to complex partial seizure-like symptoms. Methods and Findings Suitable data for such analysis may provide various physiological signals reflecting brain laterality, as for example bilateral electrodermal activity (EDA) that is closely related to limbic modulation influences. With this purpose we have performed measurement and analysis of bilateral EDA and compared the results with psychometric measures of complex partial seizure-like symptoms, depression and actually experienced stress in 44 patients with unipolar depression and 35 healthy controls. The results in unipolar depressive patients show that during rest conditions the patients with higher level of complex partial seizure like symptoms (CPSI) display increased level of EDA transinformation (PTI) calculated between left and right EDA records (Spearman correlation between CPSI and PTI is r = 0.43, p = 0.004). Conclusions The result may present potentially useful clinical finding suggesting that increased EDA transinformation (PTI) could indirectly indicate increased neural synchrony as a possible indicator of epileptiform activity in unipolar depressive patients treated by serotoninergic antidepresants.

Traumatic Stress, Dissociation, and Limbic Irritability in Patients with Unipolar Depression Being Treated with SSRIs

Recent evidence suggests that stressful experiences may be related to deficits in inhibitory functions and temporolimbic epileptic-like activity. The latter may produce psychosensory seizure-like symptoms that may also appear in nonepileptic conditions. This study assesses whether the increased presence of the seizure-like symptoms in 113 unipolar depressive patients treated with SSRIs is associated with significantly more severe symptoms of depression, traumatic stress, and dissociation in comparison with 86 healthy controls. Results indicate that seizure-like symptoms in depressive patients have significant association with depression, symptoms of dissociation, and traumatic stress. This association suggests that processess generating seizure-like symptoms may be related to symptoms of depression, traumatic stress, and dissociation.

Epileptiform Activity in Alcohol Dependent Patients and Possibilities of Its Indirect Measurement

Background Alcohol dependence during withdrawal and also in abstinent period in many cases is related to reduced inhibitory functions and kindling that may appear in the form of psychosensory symptoms similar to temporal lobe epilepsy frequently in conditions of normal EEG and without seizures. Because temporal lobe epileptic activity tend to spread between hemispheres, it is possible to suppose that measures reflecting interhemispheric information transfer such as electrodermal activity (EDA) might be related to the psychosensory symptoms. Methods and Findings We have performed measurement of bilateral EDA, psychosensory symptoms (LSCL-33) and alcohol craving (ACQ) in 34 alcohol dependent patients and 32 healthy controls. The results in alcohol dependent patients show that during rest conditions the psychosensory symptoms (LSCL-33) are related to EDA transinformation (PTI) between left and right EDA records (Spearman r = 0.44, p<0.01). Conclusions The result may present potentially useful clinical finding suggesting a possibility to indirectly assess epileptiform changes in alcohol dependent patients.