Dissociative symptoms reflect levels of tumor necrosis factor alpha in patients with unipolar depression.

Recent evidence indicates that the nature of interactions between the nervous system and immune system is important in the pathogenesis of depression. Specifically, alterations in pro-inflammatory cytokines have been related to the development of several psychological and neurobiological manifestations of depressive disorder, as well as to stress exposure. A number of findings point to tumor necrosis factor alpha (TNF-α) as one of the central factors in these processes. Accordingly, in the present study, we test the hypothesis that specific influences of chronic stressors related to traumatic stress and dissociation are related to alterations in TNF-α levels. We performed psychometric measurement of depression (Beck Depression Inventory [BDI]-II), traumatic stress symptoms (Trauma Symptom Checklist [TSC]-40), and psychological and somatoform dissociation (Dissociative Experiences Scale [DES] and Somatoform Dissociation Questionnaire [SDQ]-20, respectively), and immunochemical measure of serum TNF-α in 66 inpatients with unipolar depression (mean age 43.1 ± 7.3 years). The results show that TNF-α is significantly related to DES (Spearman R=-0.42, P<0.01), SDQ-20 (Spearman R=-0.38, P<0.01), and TSC-40 (Spearman R=-0.41, P<0.01), but not to BDI-II. Results of the present study suggest that TNF-α levels are related to dissociative symptoms and stress exposure in depressed patients.

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.

Dissociative symptoms and neuroendocrine dysregulation in depression.

BACKGROUND: Dissociative symptoms are traditionally attributed to psychological stressors that produce dissociated memories related to stressful life events. Dissociative disorders and dissociative symptoms including psychogenic amnesia, fugue, dissociative identity-disorder, depersonalization, derealization and other symptoms or syndromes have been reported as an epidemic psychiatric condition that may be coexistent with various psychiatric diagnoses such as depression, schizophrenia, borderline personality disorder or anxiety disorders. According to recent findings also the somatic components of dissociation may occur and influence brain, autonomic and neuroendocrine functions. At this time there are only few studies examining neuroendocrine response related to dissociative symptoms that suggest significant dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. The aim of the present study is to perform examination of HPA axis functioning indexed by basal cortisol and prolactin and test their relationship to psychic and somatoform dissociative symptoms. MATERIAL/METHODS: Basal cortisol and prolactin and psychic and somatoform dissociative symptoms were assessed in 40 consecutive inpatients with diagnosis of unipolar depression mean age 43.37 (SD=12.21). RESULTS: The results show that prolactin and cortisol as indices of HPA axis functioning manifest significant relationship to dissociative symptoms. Main results represent highly significant correlations obtained by simple regression between psychic dissociative symptoms (DES) and serum prolactin (R=0.55, p=0.00027), and between somatoform dissociation (SDQ-20) and serum cortisol (R=-0.38, p=0.015). CONCLUSIONS: These results indicate relationship between HPA-axis reactivity and dissociative symptoms in unipolar depressive patients that could reflect passive coping behavior and disengagement.

Depression, cortisol and somatoform dissociative symptoms.

OBJECTIVE: According to recent findings neuroendocrine response related to dissociative symptoms is related to dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis but HPA axis functioning as related to dissociation is only partially understood. METHOD: With the aim to test the relationship between basal serum cortisol and dissociative symptoms measured as somatoform and psychic dissociation we performed clinical testing and biochemical analysis in 30 inpatients with diagnosis of unipolar depression (mean age 41.46, SD=13.68). RESULTS: The results show that cortisol as an index of HPA axis functioning manifests significant relationship to somatoform dissociative symptoms (r=-0.40; p=0.014). CONCLUSIONS: The result indicates relationship between HPA-axis reactivity and somatoform dissociative symptoms in unipolar depressive patients and suggests that somatoform dissociation presents a defense mechanism related to a passive coping response.

Dissociation, epileptic-like activity and lateralized electrodermal dysfunction in patients with schizophrenia and depression.

OBJECTIVES: Recent evidence indicates frequent EEG abnormalities in dissociated patients. This evidence is in agreement with findings that in certain psychiatric patients, psychosensory symptoms of epileptogenic nature, the so-called complex partial seizure-like symptoms occur. With respect to these findings, a hypothesis examined in this study states that increased level of experienced traumatic stress and dissociation in pathological conditions such as schizophrenia or depression relates to increased score of complex partial seizure-like symptoms. Also is suggested that the complex partial seizure-like symptoms might be related to unilateral hemispheric electrophysiological dysfunction, stress and dissociation. PARTICIPANTS AND METHODS: Psychometric assessment of dissociation, stress and measurement of right-left asymmetry of bilateral EDA in patients with schizophrenia (N=34) and depression (N=41) in comparison to healthy controls (N=36). RESULTS: Results indicate that increased traumatic stress and dissociation in both groups of patients significantly relate to increased level of complex partial seizure-like symptoms, and may cause the right-left EDA asymmetry. CONCLUSIONS: The data suggest relationship between left-hemispheric asymmetry and sympathetic over-activation in schizophrenia, and between right-hemispheric asymmetry with sympathetic under-activation in depression.

Depression, prolactin and dissociated mind.

OBJECTIVES: Usual neuroendocrinological manifestation of traumatic stress and dissociation is dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis. The aim of the present study is to perform examination of HPA axis as indexed by basal serum prolactin and test its relationship to dissociative symptoms and symptoms of traumatic stress. PATIENTS AND METHODS: 25 inpatients treated at the university hospital with diagnosis of unipolar depression mean age 41.23 (SD=11.53) were assessed using psychometric measures of dissociation (DES) and traumatic symptoms (TSC-40), and using standard biochemical analytical methods basal serum prolactin levels were investigated. RESULTS: Data show that prolactin manifests significant relationship to dissociative symptoms (r=0.52, p=0.004). Significant correlation was not found between prolactin and traumatic symptoms measured by TSC-40 (r=0.31, p=0.07). CONCLUSIONS: The present data suggest that serum prolactin levels in unipolar depressive patients are related to dissociative symptoms that is likely caused by passive coping mechanisms leading to dissociation.

Chaotic neural response during conflicting Stroop task reflects the level of serum cortisol in patients with unipolar depression.

OBJECTIVE: According to recent findings detecting a cognitive conflict is related to activation of anterior cingulate cortex (ACC) and central autonomic network. Several recent findings also suggest the hypothesis that the cognitive conflict is related to specific nonlinear chaotic changes of the neural signal. This conflict related activation elicits autonomic responses which can be assessed by psychophysiological measures such as heart rate variability calculated as beat to beat R-R intervals (RRI). METHOD: The present study used Stroop word-colour test as an experimental approach to psychophysiological study of cognitive conflict in connection with RRI measurement, assessment of serum cortisol and calculation of largest Lyapunov exponents in nonlinear data analysis of RRI time series in 30 patients with unipolar depression. RESULTS: Significant correlation -0.45 (p<0.01) between largest Lyapunov exponents during conflicting Stroop task and serum cortisol levels has been found. CONCLUSIONS: The study indicates that a defect of neural inhibition during conflicting Stroop task is closely related to decreased serum cortisol levels which probably reflect defense psychological mechanisms.

Psychobiology of dissociation and its clinical assessment.

OBJECTIVE: Dissociation is often defined as partial or total disconnection between memories of the past, awareness of identity and of immediate sensations, and control of bodily movements, often resulting from traumatic experiences, intolerable problems, or disturbed relationships. This type of reaction to a psychological and/or physical trauma has often various neurobiological consequences and its clinical assessment has received enormous interest in recent psychological and neuroscience research. METHODS: Psychometric parameters of the Czech version of the Dissociative Experiences Scale were tested from the viewpoints of internal consistency, validity and factor structure, using data from a sample of n=783 adults, divided into three groups (epilepsy n=243, depression n=357, norm n=183), average age 39 years, SD=13.5. RESULTS: Findings of this study demonstrated that reliability, validity and factor structure of the Czech version of the Dissociative Experiences Scale correspond to those of the original English version. CONCLUSIONS: The Czech version of the questionnaire may be considered a suitable tool for estimating subjectively experienced dissociative symptoms.

Lateralized electrodermal dysfunction and complexity in patients with schizophrenia and depression.

OBJECTIVE: Recent evidence indicates that in psychiatric patients with schizophrenia and depression, lateralized EDA changes linked to temporal-limbic electrophysiological dysfunction occur. These clinical findings provide evidence for brain asymmetry and disruptions related to integrative brain activity in pathological conditions. METHODS: These changes in brain asymmetry may be assessed by linear analysis of EDA measurement and nonlinear analysis of brain complexity calculated as information entropy. Two groups of patients with established diagnosis of paranoid schizophrenia (N=35), unipolar depression (N=35) and a control group of 35 healthy controls were examined by measurement of bilateral electrodermal activity (EDA). In non-linear data analysis of the EDA time series in resting state the method of recurrence quantification analysis was applied. RESULTS: In these patients significant right-left EDA asymmetry and asymmetry of information entropy calculated by non-linear recurrence quantification analysis of EDA records have been found. Similar asymmetry has not been observed in the group of healthy controls. CONCLUSIONS: Because information entropy reflects the complexity of the deterministic structure in the system, then unilaterally increased entropy in patients with schizophrenia and depression likely indicates specific nonlinear disturbances in limbic circuits that modulate EDA. These data are in accordance with recent findings that indicate apparent differences in nonlinear neural patterns in the psychiatric diseases and nonlinear behavior of healthy brain.

Depression, traumatic dissociation and epileptic-like phenomena.

OBJECTIVES: According to recent findings trauma and stress are important etiological factors in pathogenesis of depression. As characteristic features of depressive cognition have been reported intrusive thoughts and memory disturbances similar to posttraumatic symptoms known in patients with posttraumatic stress disorder or dissociative disorders. Hypothetically is also suggested a close relationship of traumatic dissociation and epileptic-like phenomena. SETTINGS AND DESIGN: In the clinical study were assessed 70 adult people with a diagnosis of depression and 50 healthy controls. In the assessment were used 6 measures for symptoms of dissociation, depression, traumatic stress and psychosenzoric symptoms of epileptic origin (the so-called complex partial seizure-like symptoms). RESULTS: Reported data show that a great number of depressive patients who met the cut-off score for dissociative disorders (34.2%, N=24) had significantly higher traumatization, depression, subjectively experienced stress and complex partial seizure-like symptoms than the whole group of patients and the controls. Most significant traumatization has been found in patients who met the cut-off score of psychosenzoric epileptic-like symptoms which is characteristic for the epilepsy spectrum disorder (5.7%, N=4). MAIN FINDINGS: Significant correlations of these assessed symptoms suggest close relationship between traumatic stress and dissociation in depression. This close relationship of dissociative symptomatology and traumatic stress also implicates an important role of dissociative processes in depression as a typical manifestation of depressive cognition. Assessed relationship between traumatic distress and complex partial seizure-like symptoms suggests a possible role of epileptic-like phenomena in dissociative states related to depression. CONCLUSIONS: Assessed relationship between traumatization, depression and epileptic-like phenomena in the patients who met cut-off score for epilepsy spectrum disorder can contribute to the problem of indication of several depressive patients to anticonvulsant therapy because of reported evidence that a clear majority of patients with epilepsy spectrum disorder respond well to anticonvulsant treatment. Careful assessment of this test battery thus may be useful also for anticonvulsant treatment strategy.