Factors affecting treatment compliance in patients with bipolar I disorder during prophylaxis: a study from Turkey

Objectives

Treatment noncompliance is one of the most frequent causes of relapse and recurrence in patients with bipolar I disorder. Treatment compliance among patients with bipolar disorder is affected by individual patients’ features, the disease itself, doctor-patient relationships and patients’ socio-economic and cultural characteristics. This study aimed to determine the factors affecting treatment compliance during the treatment of bipolar disorder and contribute to current clinical strategies.

Methods

Data were collected from 78 volunteers with bipolar I disorder in remission; all volunteers were being treated solely with mood stabilisers. Sociodemographic and clinical data were gathered through a semi-structured interview designed by researchers. The Hamilton Depression Rating Scale and the Young Mania Rating Scale were both administered to assess remission of bipolar I disorder, and a self-report scale, the Medication Adherence Rating Scale, was administered to assess medication adherence.

Results

Treatment compliant patients reported that they had received adequate social support and had been sufficiently informed by their physicians about the illness and treatment. Treatment compliant individuals with higher rates of hospitalisations and the results indicate that the number of depressive episodes adversely affects treatment compliance. There was not a statistically significant difference in treatment compliance based on duration of illness, euthymia, time, total number of episodes, age of onset, predominant polarity, drug doses, number of daily medications, frequency of daily medications, or type of mood stabiliser used.

Conclusions

These results indicate that there are differences between compliant and non-compliant bipolar I disorder patients in terms of adequate social support, information provided by the physician about the illness and treatment, number of depressive episodes and number of hospitalisations.     

The clinical impact of mood disorder comorbidity on social anxiety disorder

Background

High comorbidity rates of mood disorders have been reported in patients with social anxiety disorder (SAD). Our study aims to identify the frequency of comorbid Axis I disorders in patients with SAD and to investigate the impact of psychiatric comorbidity on SAD.

Methods

The study included 247 patients with SAD. Thirty eight patients with bipolar depression (SAD-BD), 150 patients with major depressive disorder (SAD-MDD) and 25 patients who do not have any mood disorder comorbidity (SAD-NOMD) were compared.

Results

Around 90% of SAD patients had at least one comorbid disorder. Comorbidity rates of lifetime MDD and BD were 74.5% and 15.4%, respectively. There was no comorbidity in the SAD-NOMD group. Atypical depression, total number of depressive episodes and rate of PTSD comorbidity were higher in SAD-BD than in SAD-MDD. Additionally, OCD comorbidity was higher in SAD-BD than in SAD-NOMD. SAD-MDD group had higher social anxiety severity than SAD-NOMD.

Conclusions

Mood disorder comorbidity might be associated with increased severity and decreased functionality in patients with SAD.     

Serum lipids,metabolic syndrome and lifetime suicide attempts in patients with bipolar disorder

Objective

Bipolar disorder is associated with a high risk of suicide. Many clinical characteristics and, recently, biomarkers have been studied with the aim to find useful predictors of suicidality. The role of serum lipids has also been explored albeit with conflicting results; however, few studies have been focused on patients with bipolar disorder.Aim of our study is to investigate whether serum cholesterol, triglycerides, HDL-c and metabolic syndrome are associated with lifetime suicide attempts in a large naturalistic sample of patients with bipolar disorder.

Methods

220 patients with bipolar disorder were included. History of lifetime suicide attempts was systematically and retrospectively assessed for each patient. Blood exams testing total cholesterol, triglycerides, and HDL-c levels were performed, and metabolic syndrome was diagnosed according to NCEP ATP-III modified criteria. Serum lipid levels and metabolic syndrome were compared in patients with or without history of suicide attempt. According to a theory that links impulsivity and violence with low cholesterol, the association between lipid levels and violent suicidal behavior was also assessed.

Results

Lifetime suicide attempts rate was 32.3%. There were no statistically significant differences between patients with and without lifetime suicide attempts in cholesterol, triglycerides, HDL-c levels, and the prevalence of metabolic syndrome. No differences in the same variables were found in violent suicide attempters compared with nonviolent ones. Clinical characteristics such as gender, low education, higher number of manic and depressive episodes, and taking more medications for bipolar disorder were associated with lifetime suicide attempts.

Conclusions

Our results do not support the hypothesis of a strong association between serum lipid levels and suicide in patients with bipolar disorder.     

A comparison of life events in patients with unipolar disorder or bipolar disorder and controls

Objective

The present study aimed to explore the association between stressful life events (LEs) and the development of affective psychopathology.

Method

Thirty patients with unipolar disorder and 30 patients with bipolar disorder were compared to 60 matched healthy controls in regard to the rate of stressful LEs. Assessment measures included the Beck Depression Inventory, the Adult Life Events Questionnaire, and the Childhood Life Events List.

Results

The entire sample of affective patients had more LEs in general, more negative LEs, and more loss-related LEs in the year preceding their first depressive episode as compared with normal controls. Subjects with unipolar disorder had more positive LEs and more achievement LEs, whereas subjects with bipolar disorder had more uncontrollable LEs in the year preceding the first depressive episode. The relationship between LEs and manic episodes was prominent in the year preceding the first manic episode, with subjects with bipolar disorder reporting more LEs in general and more ambiguous events in that year. Almost no significant differences on LE frequency were observed in the year before the last depressive and manic episodes in the patient groups with unipolar and bipolar disorder. A significant relationship was found between childhood LEs and the development of affective disorders in adulthood, with patients with unipolar disorder exhibiting less positive and achievement LEs.

Conclusions

In both the unipolar and the bipolar groups, the major impact of LEs on the onset of affective disorders was found in the year before the first depressive or manic episodes. This suggests that the accumulation of stressful LEs at this crucial period contributes to the precipitation of a pathological response mechanism. Once established, this mechanism would be reactivated in the future by even less numerous and less severe stressors, compatible with the kindling hypothesis.     

Newly diagnosed major depressive disorder and the risk of erectile dysfunction: A population-based cohort study in Taiwan

Introduction

The primary aim of this study was to explore the incidence rate of erectile dysfunction (ED) among major depressive disorder (MDD) patients in an Asian country. The second aim was to compare the risk of ED in MDD patients that were treated using antidepressants with a high risk-ED, antidepressants with a low risk-ED, or without treatment.

Methods

We identified 4339 male patients with newly diagnosed MDD using the National Health Database. Four matched controls per case were selected for the study.

Results

The mean age of the participants was 42.3±16.9. A higher crude HR of 3.6 (95% CI: 2.8–4.6) was seen in the male patients with MDD. After adjusting for obesity, monthly income, urbanization level, and comorbidity, the MDD patients had a 3.2-fold higher HR for an ED diagnosis than the controls. Patients with untreated depression had the highest risk of ED, compared to the control group (HR=3.9). Patients treated with IHiRA had a medium risk of developing ED (HR=3.6), and patients treated with ILoRA had the lowest risk of ED (HR: 2.5).

Conclusion

This prospective cohort study found an association between ED and prior MDD. Patients with untreated depression may have the highest risk of developing ED.     

Impulsivity in children and adolescents with mood disorders and unaffected offspring of bipolar parents

Objective

Increased impulsivity seems to be present across all phases of bipolar disorder (BD). Impulsivity may therefore represent an endophenotype for BD, if it is also found among normal individuals at high genetic risk for mood disorders. In this study, we assessed impulsivity across four different groups of children and adolescents: patients with BD, major depressive disorder (MDD) patients, unaffected offspring of bipolar parents (UO), and healthy controls (HC).

Subjects and Methods

52 patients with BD, 31 with MDD, 20 UO, and 45 HC completed the Barratt Impulsiveness Scale (BIS-11), an instrument designed to measure trait impulsivity.

Results

UO displayed significantly higher total BIS-11 impulsivity scores than HC (p = 0.02) but lower scores than BD patients (F = 27.12, p < 0.01). Multiple comparison analysis revealed higher BIS-11 total scores among BD patients when compared to HC (p < 0.01) and UO (p < 0.01). MDD patients had higher BIS-11 scores when compared to HC (p < 0.01). Differences between MDD patients and UO, as well as between MDD and BD patients, were not statistically significant.

Conclusion

Our findings suggest that trait impulsivity is increased among children and adolescents with mood disorders, as well as in unaffected individuals at high genetic risk for BD.     

The loudness dependence of the auditory evoked potential (LDAEP) in schizophrenia,bipolar disorder,major depressive disorder,anxiety disorder,and healthy controls

Background

Serotonergic dysfunction in schizophrenia, bipolar disorder, major depressive disorder, anxiety disorder, and healthy controls was evaluated by measuring the activity of the loudness dependence of the auditory evoked potential (LDAEP).

Methods

The 357 subjects who were evaluated comprised 55 normal controls, 123 patients with major depressive disorder, 37 with bipolar disorder, 46 with schizophrenia, 37 with panic disorder (PD), 31 with generalized anxiety disorder (GAD), and 28 with post-traumatic stress disorder (PTSD).

Results

LDAEP was significantly stronger in healthy controls than in patients with either bipolar disorder (p = 0.025) or schizophrenia (p = 0.008), and significantly stronger in patients with major depressive disorder than in those with bipolar disorder (p = 0.01) or schizophrenia (p = 0.03). LDAEP did not differ significantly between patients with major depressive disorder and healthy control subjects (p = 0.667), or between healthy control subjects and patients with anxiety disorder, including PD (p = 0.469), GAD (p = 0.664), and PTSD (p = 0.167).

Conclusion

The findings of the present study reveal that patients with major psychiatric disorders exhibit different strengths of LDAEP according to their serotonin-related pathology. Studies controlled for psychotropic medication, menstruation cycle, and smoking are needed.     

S100B-immunopositive astrocytes and oligodendrocytes in the hippocampus are differentially afflicted in unipolar and bipolar depression: A postmortem study

Background

Previous studies have suggested that affective disorders are characterized by glial pathology. In this context, it has been hypothesized that elevated S100B serum and cerebrospinal fluid levels may represent a suitable surrogate marker. However, brain studies on the cellular distribution pattern of S100B in depressed patients are lacking so far. Such analyses are crucial, since S100B has been detected in various other cell types, even outside the central nervous system.

Methods

Therefore, we performed a first postmortem analysis on this topic in the hippocampus – which is of major importance for emotional and cognitive aspects of affective disorders. S100B-immunopositive astrocytes and oligodendrocytes were evaluated in the alveus and the CA1 pyramidal layer of patients with major depressive disorder (MDD) or bipolar I disorder (BD) compared to controls.

Results

As revealed by the optical disector cell-counting method, the numerical density of S100B-immunopositive astrocytes was bilaterally decreased in the CA1 pyramidal layer of MDD and BD patients compared to controls, whereas only the bipolar group showed a decreased density of S100B-immunopositive oligodendrocytes in the left alveus. These results were not confounded by gender, age, duration of disease, medication dosage, or autolysis time.

Conclusions

Confirming the idea of previous S100B serum and cerebrospinal fluid studies, our data suggest that S100B-immunopositive glia is dysregulated in the brains of depressed patients. These findings are in accordance with animal experiments in rodents showing a reduced astrocytic S100B-immunoreactivity in the hippocampus after pharmacological serotonin depletion (modeling depression).     

Prevalence,correlates and recognition of depression in Chinese inpatients with cancer

Objective

To determine the prevalence, correlates and recognition rates of depressive disorders (DDs) in Chinese inpatients with cancer.

Methods

Four hundred and sixty cancer inpatients were recruited from the oncology ward of a university hospital in Beijing, China. Patients were interviewed with a Chinese version of the Mini International Neuropsychiatric Interview 5.0 by eight trained psychiatrists. Case records of inpatients with DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) DDs were reviewed to determine whether treating oncologists made a diagnosis of depression, prescribed antidepressant medications and/or recommended psychiatric consultation/referral.

Results

The 1-month prevalence rates (95% confidence intervals) of DDs and major depressive disorder (MDD) were 25.9% (21.9%–29.9%) and 12.6% (9.6%–15.6%), respectively. In our multiple logistic regression analysis, being unmarried [odds ratio (OR)=1.41], cancer stage of metastasis (OR=2.35), time since cancer diagnosis ≤ 20 months (OR=2.05), frequent pain (OR=1.99~6.83) and being scored between two and four on the Eastern Cooperative Oncology Group Scale (OR=2.25~4.97) were independently associated with depression. Only 6.9% of patients with MDD were recognized by treating oncologists.

Conclusions

DDs are very common among Chinese inpatients with cancer. The high prevalence rate and low recognition rate of depression in cancer patients indicate a pressing need for routine screening, evaluation and treatment of depression in this patient population.     

Is antidepressant-associated mania always an evidence of a bipolar spectrum disorder? A case report and review of the literature

Objective

The authors consider the clinical implications of characterizing every case of antidepressant-induced mania as evidence of an underlying bipolar diathesis.

Method

The authors report the case of a 45-year-old man, with no personal or family history of bipolar symptoms, who developed manic symptoms after sertraline initiation for a first lifetime depressive episode.

Results

The patient's manic symptoms resolved rapidly with cessation of sertraline. His depressive symptoms responded to mirtazapine, and he had no further mood episodes during 2-year follow-up.

Discussion

It may not always be appropriate to identify selective serotonin reuptake inhibitor-induced manic symptoms as pathognomonic for the bipolar diathesis, particularly as the bipolar formulation has distinct implications for future pharmacologic choices.     

Suicide attempts and clinical risk factors in patients with bipolar and unipolar affective disorders

Background

Suicide is an important clinical problem in psychiatric patients. The highest risk of suicide attempts is noted in affective disorders.

Objective

The aim of the study was to look for suicide risk factors among sociodemographic and clinical factors, family history and stressful life events in patients with diagnosis of unipolar and bipolar affective disorder (597 patients, 563 controls).

Method

In the study, the Structured Clinical Interview for DSM-IV Axis I Disorders and the Operational Criteria Diagnostic Checklist questionnaires, a questionnaire of family history, and a questionnaire of personality disorders and life events were used.

Results

In the bipolar and unipolar affective disorders sample, we observed an association between suicidal attempts and the following: family history of psychiatric disorders, affective disorders and psychoactive substance abuse/dependence; inappropriate guilt in depression; chronic insomnia and early onset of unipolar disorder. The risk of suicide attempt differs in separate age brackets (it is greater in patients under 45 years old). No difference in family history of suicide and suicide attempts; marital status; offspring; living with family; psychotic symptoms and irritability; and coexistence of personality disorder, anxiety disorder or substance abuse/dependence with affective disorder was observed in the groups of patients with and without suicide attempt in lifetime history.     

Sleep disturbances in a clinical forensic psychiatric population

Objective

Poor sleep is known to cause detrimental effects on the course of diverse psychiatric disorders and is a putative risk factor for hostility and aggression. Thus, sleep may be crucial in forensic psychiatric practice. However, little is known about the prevalence of sleep disturbances in these complex psychiatric patients.

Methods

In this study we investigated the presence of sleep disorders and subjective sleep quality using the Sleep Diagnosis List (SDL), the Pittsburgh Sleep Quality Index (PSQI), interviews addressing the causes of sleep complaints, and file information on sleep medications in 110 patients admitted to a forensic psychiatric hospital.

Results

Almost 30% of the participants suffered from one or more sleep disorders, especially insomnia. An even larger proportion of the participants (49.1%) experienced poor sleep quality. Interestingly, patients with an antisocial personality disorder or traits were particularly dissatisfied with their sleep. The most common causes of sleep problems were suboptimal sleep hygiene, stress or ruminating, negative sleep conditioning, and side effects of psychotropic medication. Of the poor sleepers, 40.7% received a hypnotic drug.

Conclusion

Despite intensive clinical treatment, sleep problems are experienced by a large number of forensic psychiatric patients. It would be worthwhile to examine the effects of pharmacological and non-pharmacological sleep interventions on both psychiatric symptoms and reactive aggressive behavior in forensic patients.     

Neutrophil gelatinase-associated lipocalin: A novel inflammatory marker associated with late-life depression

Objective

Systemic low graded inflammation has been identified as a possible biological pathway in late-life depression. Identification of inflammatory markers and their association with characteristics of depression is essential with the aim to improve diagnosis and therapeutic approaches. This study examines the determinants of plasma Neutrophil Gelatinase-Associated Lipocalin (NGAL), which is selectively triggered by TNFα receptor 1 signaling within the central nervous system, and its association with late-life depressive disorder.

Methods

Baseline data were obtained from a well-characterized prospective cohort study of 350 depressed and 129 non-depressed older persons (≥ 60 years). Past 6 month diagnosis of major depressive disorder (MDD) according to DSM-IV-TR criteria was assessed with the Composite International Diagnostic Interview (CIDI 2.0). Potential determinants of plasma NGAL included sociodemographic characteristics, lifestyle and psychiatric and physical comorbidity.

Results

Plasma NGAL concentrations were significantly associated with age, male gender, smoking and waist circumference. Adjusted for these determinants, depressed patients had significantly higher NGAL plasma levels compared to non-depressed comparison group. Depressed patients who did not meet full criteria for MDD in the month before sampling (partially remitted) had lower plasma NGAL levels compared with those who did. Subjects with a recurrent depression had higher plasma NGAL levels compared to those with a first episode. NGAL levels were neither related with specific symptom profiles of depression nor with antidepressant drug use.

Conclusion

Adjusted for confounders, NGAL plasma levels are increased in depressed older persons, without any effect of antidepressant medication and age of onset.     

Discrimination between schizophrenia and major depressive disorder by magnetic resonance imaging of the female brain

Background

Although schizophrenia and major depressive disorder (MDD) differ on a variety of neuroanatomical measures, a diagnostic tool to discriminate these disorders has not yet been established. We tried to identify structural changes of the brain that best discriminate between schizophrenia and MDD on the basis of gray matter volume, ventricle volume, and diffusion tensor imaging (DTI).

Method

The first exploration sample consisted of 25 female patients with schizophrenia and 25 females with MDD. Regional brain volumes and fractional anisotropy (FA) values were entered into a discriminant analysis. The second validation sample consisted of 18 female schizophrenia and 16 female MDD patients.

Results

The stepwise discriminant analysis resulted in correct classification rates of 0.80 in the schizophrenic group and 0.76 in MDD. In the second validation sample, the obtained model yielded correct classification rates of 0.72 in the schizophrenia group and 0.88 in the MDD group.

Conclusion

Our results suggest that schizophrenia and MDD have differential structural changes in the examined brain regions and that the obtained discriminant score may be useful to discriminate the two disorders.     

Evidence for specific cognitive deficits in visual information processing in patients with OCD compared to patients with unipolar depression

Objective

Neuropsychological studies comparing cognitive performance in patients suffering from Obsessive-Compulsive Disorder (OCD) or Major Depressive Disorder (MDD) revealed deficits in the domains of verbal fluency and viso-motor speed/set shifting in both groups. Spatial working memory deficits, however, have been identified as specific markers of OCD. As yet, it has not been substantiated whether deficits in visual organization and complex visual memory are also specific to OCD and are not shared by MDD.

Method

Test performance in seven cognitive domains was assessed in 40 OCD patients, 20 MDD patients, and 40 healthy controls. Patient groups were matched according to severity of depressive symptoms.

Results

Deficits shared by both patient groups, as compared to controls, were found in delayed spatial recall and verbal fluency while verbal memory was normal in both patient groups. Only patients with OCD, but not MDD patients were impaired in the domains visual memory, viso-motor speed/set shifting, visual organization, and problem solving. In addition, OCD patients differed significantly from MDD subjects in visual organization and problem solving. Visual organization scores correlated significantly with severity of current compulsions in the OCD group (r = −.324).

Conclusions

OCD patients demonstrate difficulties in visual organization and mental manipulation of complex visual material, which are not accounted for by depressive symptoms and which constitute a specific cognitive deficit of the disorder.     

The use of 15-point hypomanic checklist in differentiating bipolar I and bipolar II disorder from major depressive disorder

Objectives

Individuals with bipolar disorder (BP) are often misdiagnosed with major depressive disorder (MDD). In this study, we developed a Chinese version of 15-point hypomania scale (HCL-15) in order to determine its sensitivity and specificity in the diagnosis of BP and BP-II in particular.

Methods

A total of 623 individuals suffering a major depressive episode (MDE) were systematically interviewed with both Structured Clinical Interview for DSM-IV-TR Axis I Disorders, Patient Edition, and HCL-15. A cutoff score of 8 or more in HCL-15 was suggested for BP.

Results

Of the 623 depressed patients, 115 (18.5%) actually required a diagnosis of BP-I, and another 159 (25.5%) could be more appropriately diagnosed with BP-II, according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, criteria. The sensitivity of 15-HCL in detection of BP-II was 0.78 and 0.46 for BP-I; the specificity was 0.9 and 0.69, respectively. The specificity of HCL-15 for BP versus MDD was as high as 0.93. Approximately 60%–80% of all questions in the HCL-15 questionnaire revealed positive responses from patients, while items 11 and 12, measuring the consumption of alcohol, coffee and cigarettes, demonstrated a low positive response rate.

Conclusions

The HCL-15 assessment scale was fairly sensitive and highly specific for a BP-II diagnosis but not for a BP-I diagnosis. Some items in the HCL-15 symptom list need to be further modified to better fit Chinese culture and customs. The HCL-15 scale could be a useful tool in clinical practice for screening individuals with BP-II in order to avoid a misdiagnosis of MDD.     

The association between serum levels of neopterin and number of depressive episodes of major depression

Background

There is an interaction between the immune system and the central nervous system by means of hormones, peptides, and neurotransmitters. The aims of the present study were to determine whether the serum neopterin levels in patients with major depression (MD) differ from a healthy control group and to investigate the relationship between previous MD episodes and serum neopterin levels.

Methods

Thirty patients who were admitted to the GATA Psychiatry Outpatient Clinics and were diagnosed with MD according to DSM-IV, and who agreed to participate in the study, were included in the study. Twenty-six healthy volunteers matched for age, gender, and level of education who agreed to participate in the study were served as controls. Peripheral venous blood samples were obtained from the patients and the control group for complete blood count, routine biochemistry, and the detection of serum neopterin levels. The analyses were performed in the laboratory of the GATA Department of Biochemistry.

Results

There was no significant difference between the MD group and the healthy controls with respect to age, level of education, smoking, and gender. Serum neopterin levels of the MD group who had experienced two or more episodes were higher than the first-episode group and the control group. Age of onset and the number of previous episodes had an independent impact on serum neopterin levels in MD patients, while smoking did not show any effect.

Conclusion

In the present study, the neopterin levels of patients who had experienced two or more episodes were higher than the first-episode depressive group and healthy control group. It was also found that the number of previous depressive episodes and the ages of the MD cases had an independent effect on serum neopterin levels.     

Ventilatory inefficiency in major depressive disorder: A potential adjunct for cardiac risk stratification in depressive disorders?

Background

Cardiopulmonary exercise testing (CPET) provides insights into ventilatory, cardiac and metabolic dysfunction in heart and lung diseases and might play a role in cardiac risk stratification in major depressive disorder (MDD).

Objective

The VE/VCO₂-slope indicates ventilatory efficiency and has been applied to stratify the cardiac risk in heart failure (HF). Therefore, the current study was conducted to evaluate and classify ventilatory efficiency and its relationship to physical fitness and disease severity in MDD.

Methods

Exhaustive incremental exercise testing was completed by 15 female MDD patients and pair matched controls. The ventilatory threshold (VT) and the VE/VCO₂-slope were assessed. Statistical analyses were conducted by means of MANOVAs and follow-up univariate ANOVAs.

Results

In patients with MDD, significant different relative work rates and oxygen uptakes at the VT in comparison to healthy controls were observed. Furthermore, we found an increased VE/VCO₂-slope in depressed patients. We additionally report an inverse relationship between the VE/VCO₂-slope and peak power output as well as peak oxygen uptake solely in patients. We did not observe any association of assessed parameters with disease severity.

Conclusion

CPET measures indicate ventilatory inefficiency in patients with MDD. The elevated VE/VCO₂-slope indicates that patients with MDD need to ventilate significantly more to a given amount of developing CO₂. Further investigations are needed to verify the application of the ventilatory classification system to stratify cardiovascular risk in depressive disorder.     

Electrodermal hyporeactivity as a trait marker for suicidal propensity in uni- and bipolar depression

Background

A meta-analysis of studies investigating electrodermal activity in depressed patients, suggested that electrodermal hyporeactivity is sensitive and specific for suicide.

Aims

To confirm this finding and to study electrodermal hyporeactivity relative to type and severity of depression, trait anxiety, its stability and independence of depressive state.

Method

Depressed inpatients (n = 783) were tested for habituation of electrodermal responses and clinically assessed using the Beck Depression Inventory (BDI) and the STAI-Trait scale for trait anxiety.

Results

The high sensitivity and raw specificity of electrodermal hyporeactivity for suicide were confirmed. Its prevalence was highest in bipolar disorders and was independent of severity of depression, trait anxiety, gender and age. Hyporeactivity was stable, while reactivity changed into hyporeactivity in a later depressive episode.

Conclusions

The findings support the hypothesis that electrodermal hyporeactivity is a trait marker for suicidal propensity in depression.     

Preattentive dysfunction in bipolar disorder: A MEG study using auditory mismatch negativity

Background

Neuropsychological studies have demonstrated that cognitive dysfunction represents pathophysiological mechanisms underlying bipolar disorder. However, information processing deficits in bipolar disorder have not often been examined electrophysiologically. Here, we examined preattentive processing and sensory information processing using mismatch field (MMNm) and P1m components, respectively, using magnetoencephalography.

Methods

Ten patients with bipolar disorder and 20 healthy volunteers participated in the study. The participants were presented with auditory stimuli sequences comprising standard and deviant stimuli. MMNm was elicited in response to changes in duration and frequency of pure-tone stimuli and a vowel across-category change.

Results

The magnetic global field power of MMNm in the right hemisphere under the pure-tone condition was significantly delayed in patients with bipolar disorder compared to healthy volunteers, and that of P1m did not differ between the two groups. The MMNm dipole in the left hemisphere was located inferior in patients with bipolar disorder than in healthy volunteers. This finding did not correlate with clinical symptoms.

Conclusions

Information processing at the preattentive level is impaired in patients with bipolar disorder irrespective of clinical symptoms, and this dysfunction is not due to sensory level dysfunction. The quality of preattentive information processing impairment is different between patients with bipolar disorder and patients with major depressive disorder, as shown by the MMNm latency and power differences.