White matter hyperintensities and their associations with suicidality in patients with major affective disorders

Plasma Apo-E mediated corticospinal tract abnormalities and suicidality in patients with major depressive disorder

This study aims to explore the link between Apo-E, brain white matter, and suicide in patients with major depressive disorder (MDD) to investigate the potential neuroimmune mechanisms of Apo-E that may lead to suicide. Thirty-nine patients with MDD (22 patients with suicidality) and 57 age, gender, and education-matched healthy controls participated in this study, provided plasma Apo-E samples, and underwent diffusion tensor imaging scans. Plasma Apo-E levels and white matter microstructure were analyzed among the MDD with suicidality, MDD without suicidality, and HC groups using analysis of variance with post hoc Bonferroni correction and tract-based spatial statistics (TBSS) with threshold-free cluster enhancement correction. Mediation analysis investigated the relationship between Apo-E, brain white matter, and suicidality in MDD. The MDD with suicidality subgroup had higher depressive and suicide scores, longer disease course, and lower plasma Apo-E levels than MDD without suicidality. TBSS revealed that the MDD non-suicide subgroup showed significantly increased mean diffusivity in the left corticospinal tract and body of the left corpus callosum, as well as increased axial diffusivity in the left anterior corona radiata and the right posterior thalamic radiation compared to the suicidal MDD group. The main finding was that the increased MD of the left corticospinal tract contributed to the elevated suicide score, with Apo-E mediating the effect. Preliminary result that Apo-E's mediating role between the left corticospinal tract and the suicide factor suggests the neuroimmune mechanism of suicide in MDD. The study was registered on ClinicalTrials.gov (NCT03790085).

Altered Levels of Plasma Inflammatory Cytokines and White Matter Integrity in Bipolar Disorder Patients With Suicide Attempts

OBJECTIVE

Bipolar disorder (BD) has a higher lifetime rate of suicide attempts (SA) than other psychiatric disorders. Furthermore, BD patients with SA (BD + S) are prone to a worse quality of life. However, the pathophysiology of BD + S is poorly understood. To further reveal the potential mechanisms of BD + S, abnormalities in peripheral plasma inflammatory cytokines and brain white matter (WM) in BD + S, as well as the correlation between them are investigated.

METHODS

We tested the levels of TNF-α, IL-1β, and IL-6 in peripheral plasma and collected the diffusion tensor imaging (DTI) data from 14 BD + S, 24 BD patients without SA (BD-S), and 26 healthy controls (HCs). The three groups were matched by age and gender. The levels of TNF-α, IL-1β, and IL-6 were detected by Luminex multifactor detection technology, and the fractional anisotropy (FA) values were employed to depict the alterations of WM. Partial correlation analyses were conducted to detect correlations between levels of TNF-α, IL-1β, and IL-6 and changes of WM, and the relationships between severity of clinical symptoms, including scores of HAMD-17 and YMRS, and cytokine levels or FA values in all groups.

RESULTS

For plasma inflammatory cytokines, there was no significant difference in their levels except for IL-6 among the three groups. Post-hoc analyses revealed that increased IL-6 level was only detected in BD + S (p < 0.05, Bonferroni correction). For DTI, BD + S showed specifically decreased FA in the bilateral middle cerebellar peduncle and the left superior corona radiata compared to BD-S and HCs (p < 0.05, Bonferroni correction). Additionally, both BD + S and BD-S groups revealed decreased FA in the bilateral body and genu of corpus callosum (CC) compared to HCs (p < 0.05, Bonferroni correction). No significant correlation between plasma inflammatory cytokines and WM integrity was found. In the BD + S group, we found negative correlation between the scores of YMRS and FA values of the left middle cerebellar peduncle (r = -0.74, p = 0.035).

CONCLUSION

The inflammation and impaired WM integrity may provide a scientific basis to understand the potential mechanisms of BD + S.

Increased Amygdala-Paracentral Lobule/Precuneus Functional Connectivity Associated With Patients With Mood Disorder and Suicidal Behavior

Mood disorder patients have greater suicide risk than members of the general population, but how suicidal behavior relates to brain functions has not been fully elucidated. This study investigated how functional connectivity (FC) values between the right/left amygdala and the whole brain relate to suicidal behavior in patients with mood disorder. The participants in this study were 100 mood disorder patients with suicidal behavior (SB group), 120 mood disorder patients with non-suicidal behavior (NSB group), and 138 age- and gender-matched healthy controls (HC group). Whole-brain FC values among the three groups were compared using an analysis of covariance (ANCOVA). Compared to the NSB and HC groups, increased FC values in the right amygdala-bilateral paracentral lobule/precuneus circuit were observed in the SB group (Bonferroni-corrected, p < 0.017). The FC values in the NSB group did not differ significantly from those in the HC group (Bonferroni-corrected, p > 0.017). Moreover, there were no significant differences in FC values between mood disorder patients with suicide attempt (SA group) and mood disorder patients with suicidal ideation (SI group), while the FC values between the right amygdala and bilateral paracentral lobule/precuneus in the SA group were higher than the mean in the SI group. These findings suggest that right amygdala-paracentral lobule/precuneus dysfunction has an important role in patients with mood disorder and suicidal behavior.

Brain Functional and Structural Alterations in Women With Bipolar Disorder and Suicidality

Objective: Suicide is the leading cause of death from bipolar disorder (BD). At least 25-50% of the patients with BD will attempt suicide, with suicide rates much higher in women patients than in men. It is crucial to explore the potential neural mechanism underlying suicidality in women with BD, which will lead to understanding and detection of suicidality and prevent death and injury from suicide. Methods: Brain function and structure were measured by amplitude of low-frequency fluctuation (ALFF) and gray matter volume (GMV) in 155 women [30 women with BD and a history of suicidality, 50 women with BD without suicidality, and 75 healthy controls (HC)]. The differences in ALFF and GMV across the BD with suicidality, BD without suicidality, and HC groups were investigated. Results: BD with suicidality showed significantly increased ALFF in the left and right cuneus compared with BD without suicidality and HC groups. Moreover, the GMV in the left lateral prefrontal cortex and left cuneus in BD with suicidality were significantly lower than those in BD without suicidality and HC groups, while the GMV of the right ventral prefrontal cortex was significantly decreased in both BD with and without suicidality groups. Conclusions: This study, combining functional and structural neuroimaging techniques, may help to identify specific pathophysiological changes in women with BD and suicidality. Increased ALFF and less GMV in cuneus might represent the neuroimaging features of suicidality in women with BD. Investigating this potential neuromarker for suicidality in women with BD may lead to the ability to prevent suicidality.

Aberrant functional connectivity and graph properties in bipolar II disorder with suicide attempts

OBJECTIVE

The physiological mechanism of suicide attempt (SA) in bipolar II disorder (BD-II) remains only partially understood. The study seeks to identify the dysfunction pattern in suicide brain for BD-II patients.

METHODS

Graph theory was utilized to explore topological properties at whole-brain, module and region levels based on resting-state functional MRI (rs-fMRI) data, which acquired from 38 un-medicated BD-II patients with at least one SA, 60 none SA (NSA) patients and 69 healthy controls (HCs). Finally, the correlation relationship between graph metrics and clinical variables were estimated.

RESULTS

Compared with NSA patients and HCs, the functional connectivity strength between limbic/sub-cortical (LIMB/SubC) and frontoparietal network (FPN) were significantly weakened. Nodal strength in left head of caudate nucleus (HCN), raphe nucleus (RN), right nucleus accumbens (NAcc), right subgenual anterior cingulate cortex (sgACC) and nodal efficiency in right sgACC, right HCN for SA patients were significantly reduced relative to NSA and HCs. In particular, nodal strength in RN and nodal efficiency in right sgACC showed a significant negative correlation with Nurses' Global Assessment of Suicide Risk (NGASR) scores.

LIMITATIONS

This is a single-mode cross-sectional study, the results were not verified by multi-center data.

CONCLUSIONS

The abnormal disrupted FC between LIMB/SubC and FPN is associated with SA in BD-II patients, which increased the susceptibility of suicide. Especially, the dysfunction in RN and right sgACC predict a higher suicide risk in BD-II patients.The results can help us to understand the suicide mechanism and early judgment of suicidal behaviors for BD-II patients.

Prevalence of white matter hyperintensities is not elevated in a large sample of adolescents and young adults with bipolar disorder

OBJECTIVE

The increased prevalence rate of white matter hyperintensities is one of the most consistently reported brain abnormalities in adults with bipolar disorder. However, findings in children and adolescents with bipolar disorder are less consistent. Prior studies have been constrained by small sample sizes and/or poor age- and sex-matching of healthy controls. We examined this topic in the largest sample of adolescents with bipolar disorder to date.

METHODS

T2-weighted 3-Tesla magnetic resonance imaging data were acquired for 83 adolescents with bipolar disorder diagnosed via the Kiddie Schedule for Affective Disorders and the Schizophrenia, Present and Lifetime version semi-structured interview and 64 age- and sex-matched healthy controls. All acquired scans were examined by neuroradiologists and the presence or absence of white matter hyperintensities was determined for each participant.

RESULTS

The prevalence of white matter hyperintensities did not differ between adolescents with bipolar disorder (13.3%) and controls (21.9%; χ2 = 1.90; p = 0.168).

CONCLUSION

In contrast to the study hypothesis, the prevalence of white matter hyperintensities was not higher in adolescents with bipolar disorder than controls. The large sample size and good matching for age and sex bolster the reliability of this negative finding. Future studies are warranted to evaluate the prevalence, incidence, and predictors of white matter hyperintensities in early-onset bipolar disorder prospectively.

Bipolar Disorder and Suicide: a Review

PURPOSE OF REVIEW

Bipolar disorder has the highest rate of suicide of all psychiatric conditions and is approximately 20-30 times that of the general population. The purpose of this review is to discuss findings relevant to bipolar disorder and suicide.

RECENT FINDINGS

Risk factors include male gender, living alone, divorced, no children, Caucasian, younger age (< 35 years), elderly age (> 75 years), unemployment, and a personal history of suicide attempt and family history of suicide attempt or suicide completion, as well as predominant depressive polarity. Suicide is associated with the depressed or mixed subtypes, not mania. Although there are emerging treatments for bipolar depression, such as ketamine and TMS, lithium remains the only medication associated with lowered suicide rates in bipolar disorder. Understanding clinical and demographic risk factors for suicide in bipolar disorder remains the best way to prevent suicidal behavior. Early intervention and treatment with anti-suicidal medications, such as lithium, along with close observation and follow-up is the best way to mitigate suicide in patients with bipolar disorder.

Personalized and precision medicine as informants for treatment management of bipolar disorder

DSM-5 diagnostic categories, defined by a set of psychopathological symptoms are heterogeneous conditions that may include different biological entities, with distinct etiopathogenesis, different courses and requiring different treatment management. For bipolar disorder the major evidences for this lack of validity are the long paths before a proper diagnosis, the inconsistence of treatment guidelines, the long phases of pharmacological adjustment and the low average of long-term treatment response rates. Personalized medicine for mental disorders aims to couple established clinical-pathological indexes with new molecular profiling to create diagnostic, prognostic and therapeutic strategies precisely tailored to each patient. Regarding bipolar disorder, the clinical history and presentation are still the most reliable markers in stratifying patients and guiding therapeutic management, despite the research goes to great lengths to develop new neuropsychological or biological markers that can reliably predict individual therapy effectiveness. We provide an overview of the advancements in personalized medicine in bipolar disorder, with particular attention to how psychopathology, age at onset, comorbidity, course and staging, genetic and epigenetic, imaging and biomarkers can influence treatment management and provide an integration to the conventional treatment guidelines. This approach may offer a new and rational path for the development of treatments for targeted subgroups of patients with bipolar disorder.

White matter abnormalities of corpus callosum in patients with bipolar disorder and suicidal ideation

OBJECTIVE

Although many studies have shown that the corpus callosum (CC) may play an important role in bipolar disorder (BD) and suicide, the pathophysiological mechanism of BD underlying suicidal behavior is still unclear. This study aimed to explore the relationship between the CC, and BD and suicidal ideation using diffusion tensor imaging (DTI).

METHOD

A total of 203 participants (47 BD patients with suicidal ideation, 59 with BD without suicidal ideation, and 97 healthy controls [HC]) underwent DTI scanning at a single site. We examined the white matter integrity of the CC in the three groups.

RESULTS

A comparison among groups showed that BD patients with suicidal ideation had significant lower fractional anisotropy (FA) values than those of BD without suicidal ideation and HCs in the body and genu of the CC, and FA values of BD without suicidal ideation were significantly lower than those of HCs. However, in the splenium of corpus callosum, no difference was found between BD without suicidal ideation and HCs.

CONCLUSIONS

Our findings add to the evidence suggesting that the CC plays a key role in BD with suicidal ideation, especially with respect to the role of the genu and body of the CC subserving emotion regulation.

Neuroimaging Studies of Suicidal Behavior and Non-suicidal Self-Injury in Psychiatric Patients: A Systematic Review

Background: With around 800,000 people taking their own lives every year, suicide is a growing health concern. Understanding the factors that underlie suicidality and identifying specific variables associated with increased risk is paramount for increasing our understanding of suicide etiology. Neuroimaging methods that enable the investigation of structural and functional brain markers in vivo are a promising tool in suicide research. Although a number of studies in clinical samples have been published to date, evidence about neuroimaging correlates for suicidality remains controversial. Objective: Patients with mental disorders have an increased risk for both suicidal behavior and non-suicidal self-injury. This manuscript aims to present an up-to-date overview of the literature on potential neuroimaging markers associated with SB and NSSI in clinical samples. We sought to identify consistently reported structural changes associated with suicidal symptoms within and across psychiatric disorders. Methods: A systematic literature search across four databases was performed to identify all English-language neuroimaging articles involving patients with at least one psychiatric diagnosis and at least one variable assessing SB or NSSI. We evaluated and screened evidence in these articles against a set of inclusion/exclusion criteria and categorized them by disease, adhering to the PRISMA guidelines. Results: Thirty-three original scientific articles investigating neuroimaging correlates of SB in psychiatric samples were found, but no single article focusing on NSSI alone. Associations between suicidality and regions in frontal and temporal cortex were reported by 15 and 9 studies across four disorders, respectively. Furthermore, differences in hippocampus were reported by four studies across three disorders. However, we found a significant lack of replicability (consistency in size and direction) of results across studies. Conclusions: Our systematic review revealed a lack of neuroimaging studies focusing on NSSI in clinical samples. We highlight several potential sources of bias in published studies, and conclude that future studies should implement more rigorous study designs to minimize bias risk. Despite several studies reporting associations between SB and anatomical differences in the frontal cortex, there was a lack of consistency across them. We conclude that better-powered samples, standardized neuroimaging and analytical protocols are needed to continue advancing knowledge in this field.

Structural and functional alterations of the suicidal brain: An updated review of neuroimaging studies

Brain imaging is a non-invasive and in vivo direct estimation of detailed brain structure, regional brain functioning and estimation of molecular processes in the brain. The main objective of this review was to analyze functional and structural neuroimaging studies of individuals at risk for suicide. We reviewed articles published between 2005 and 2018, indexed in PubMed and Medline, assessing structural and functional alterations of the brain of individuals at high risk for suicide and at low risk for suicide. We reviewed functional and structural neuroimaging studies which included individuals with a history of suicidal ideation or attempt in major depressive disorder (MDD), bipolar disorder (BD), psychosis, and borderline personality disorder (BPD). We selected 45 papers that focused on suicidality in MDD, 17 papers on BD, 11 papers on psychosis, and 5 papers on BPD. The suicidal brain across psychiatric diagnoses seems to heavily involve dysfunction of the fronto-temporal network, primarily involving reductions of gray and white matter volumes in the pre-frontal cortex (PFC), anterior cingulate, and superior temporal gyrus. Nonetheless, there are several ways to define suicidal behaviour and ideation. Therefore, it still remains difficult to combine the evidence from imaging studies that used different definitions of suicidality.

Biomarkers of Suicide Attempt Behavior: Towards a Biological Model of Risk

PURPOSE OF REVIEW

The rising suicide rate in the USA will not be reversed without improved risk assessment and prevention practices. To date, the best method for clinicians to assess a patient's risk for suicide is screening for past suicide attempts in the patient and their family. However, neuroimaging, genomic, and biochemical studies have generated a body of findings that allow description of an initial heuristic biological model for suicidal behavior that may have predictive value.

RECENT FINDINGS

We review studies from the past 3 years examining potential biological predictors of suicide attempt behavior. We divide findings into two major categories: (1) structural and functional brain imaging findings and (2) biochemical and genomic findings encompassing several systems, including major neurotransmitters (serotonin, catecholamines, GABA, and glutamate), the hypothalamic pituitary adrenal (HPA) axis, the inflammasome, lipids, and neuroplasticity. The biomarkers that appear promising for assessing suicide risk in clinical settings include indices of serotonergic function, inflammation, neuronal plasticity, and lipids.

The impact of periventricular white matter lesions in patients with bipolar disorder type I

INTRODUCTION

White matter hyperintensities (WMHs) are one the most common neuroimaging findings in patients with bipolar disorder (BD). It has been suggested that WMHs are associated with impaired insight in schizophrenia and schizoaffective patients; however, the relationship between insight and WMHs in BD type I has not been directly investigated.

METHODS

Patients with BD-I (148) were recruited and underwent brain magnetic resonance imaging (MRI). Affective symptoms were assessed using Young Mania Rating Scale (YMRS) and Hamilton Depression Rating Scale (HDRS17); the presence of impaired insight was based on the corresponding items of YMRS and HDRS17.

RESULTS

Multiple punctate periventricular WMHs (PWMHs) and deep WMHs (DWMHs) were observed in 49.3% and 39.9% of the cases, respectively. Subjects with lower insight for mania had significantly more PWMHs (54.6% vs 22.2%; p < 0.05) when compared to BD-I patients with higher insight for mania. The presence of PWMHs was independently associated with lower insight for mania: patients who denied illness according to the YMRS were 4 times more likely to have PWMHs (95% CI: 1.21/13.42) than other patients.

CONCLUSIONS

Impaired insight in BD-I is associated with periventricular WMHs. The early identification of BD-I subjects with PWMHs and impaired insight may be crucial for clinicians.

Neuroanatomical correlates of attitudes toward suicide in a large healthy sample: A voxel-based morphometric analysis

Previous studies have indicated that permissive attitudes toward suicide are positively associated with mental illness (e.g., depression and loneliness). Evidence suggests that there are abnormalities in the cognitive and brain functioning of suicidal patients. Nevertheless, there has been no evidence of the correlation between attitudes toward suicide and abnormal brain structure variations in healthy people. Therefore, in this study, we seek to investigate the neuroanatomical differences in healthy participants with regard to attitudes toward suicide. The results show that permissive attitudes toward suicide were significantly correlated with gray matter volume (GMV) in the left dorsolateral prefrontal cortex (DLPFC) and the left cerebellum in the large sample (n=405), which may be related to inefficient inhibitory control of negative emotion. Then, in a subset of healthy individuals with permissive attitudes (n=113), we also observed that stronger permissive attitudes toward suicide were positively related to the larger GMV in the left DLPFC and the left middle temporal gyrus (MTG), which may be associated with sensitivity of emotional feeling. Furthermore, loneliness had a mediating effect on the relation between the DLPFC volume and attitudes toward suicide. Taken together, neuroanatomical differences in healthy participants with permissive attitudes toward suicide may provide a better understanding of permissive attitudes toward suicide as a likely risk factor for suicidal behavior.

Cerebral White Matter Lesions and Affective Episodes Correlate in Male Individuals with Bipolar Disorder

Background

Cerebral white matter lesions (WML) have been found in normal aging, vascular disease and several neuropsychiatric conditions. Correlations of WML with clinical parameters in BD have been described, but not with the number of affective episodes, illness duration, age of onset and Body Mass Index in a well characterized group of euthymic bipolar adults. Herein, we aimed to evaluate the associations between bipolar course of illness parameters and WML measured with volumetric analysis.

Methods

In a cross-sectional study 100 euthymic individuals with BD as well as 54 healthy controls (HC) were enrolled to undergo brain magnetic resonance imaging using 3T including a FLAIR sequence for volumetric assessment of WML-load using FSL-software. Additionally, clinical characteristics and psychometric measures including Structured Clinical Interview according to DSM-IV, Hamilton-Depression, Young Mania Rating Scale and Beck’s Depression Inventory were evaluated.

Results

Individuals with BD had significantly more (F = 3.968, p < .05) WML (Mdn = 3710mm3; IQR = 2961mm3) than HC (Mdn = 2185mm3; IQR = 1665mm3). BD men (Mdn = 4095mm3; IQR = 3295mm3) and BD women (Mdn = 3032mm3; IQR = 2816mm3) did not significantly differ as to the WML-load or the number and type of risk factors for WML. However, in men only, the number of manic/hypomanic episodes (r = 0.72; p < .001) as well as depressive episodes (r = 0.51; p < .001) correlated positively with WML-load.

Conclusions

WML-load strongly correlated with the number of manic episodes in male BD patients, suggesting that men might be more vulnerable to mania in the context of cerebral white matter changes.

Higher total cholesterol level is associated with suicidal ideation in first-episode schizophrenia females

There are inconsistent reports showing that the relationship between total cholesterol (TC) level and suicidality might be gender-specific. We compared 30 first-episode schizophrenia (FES) patients reporting suicidal ideation based on the Operational Criteria for Psychotic Illness (OPCRIT) checklist with 70 FES patients, who have never experienced suicidal ideation. After controlling for potential confounders, higher TC was associated with suicidal ideation only in FES females. Future studies should disentangle biological underpinnings of this gender-specific association.

Is there a neuroanatomical basis of the vulnerability to suicidal behavior? A coordinate-based meta-analysis of structural and functional MRI studies

Objective: We conducted meta-analyses of functional and structural neuroimaging studies comparing adolescent and adult individuals with a history of suicidal behavior and a psychiatric disorder to psychiatric controls in order to objectify changes in brain structure and function in association with a vulnerability to suicidal behavior.

Methods: Magnetic resonance imaging studies published up to July 2013 investigating structural or functional brain correlates of suicidal behavior were identified through computerized and manual literature searches. Activation foci from 12 studies encompassing 475 individuals, i.e., 213 suicide attempters and 262 psychiatric controls were subjected to meta-analytical study using anatomic or activation likelihood estimation (ALE).

Result: Activation likelihood estimation revealed structural deficits and functional changes in association with a history of suicidal behavior. Structural findings included reduced volumes of the rectal gyrus, superior temporal gyrus and caudate nucleus. Functional differences between study groups included an increased reactivity of the anterior and posterior cingulate cortices.

Discussion: A history of suicidal behavior appears to be associated with (probably interrelated) structural deficits and functional overactivation in brain areas, which contribute to a decision-making network. The findings suggest that a vulnerability to suicidal behavior can be defined in terms of a reduced motivational control over the intentional behavioral reaction to salient negative stimuli.

White matter abnormalities: Insights into the pathophysiology of major affective disorders

The presence of white matter hyperintensities (WMHs) has been commonly associated with poor outcome in subjects with major affective disorders. Unfortunately, WMHs may be frequently confounded by the use of psychoactive medications and duration of illness. Although findings from the current literature are quite conflicting, we proposed that subjects with WMHs may be at higher suicidal risk when compared to other subgroups without. Based on the Fazekas modified scale, the severity of WMHs may serve as a trait marker of disease. Interestingly, the presence of WMHs may represent a neurobiological marker between the underlying vulnerability and clinical presentation of major affective disorders.

The neurobiology of suicide

The stress-diathesis model posits that suicide is the result of an interaction between state-dependent (environmental) stressors and a trait-like diathesis or susceptibility to suicidal behaviour, independent of psychiatric disorders. Findings from post-mortem studies of the brain and from genomic and in-vivo neuroimaging studies indicate a biological basis for this diathesis, indicating the importance of neurobiological screening and interventions, in addition to cognitive and mood interventions, in the prevention of suicide. Early-life adversity and epigenetic mechanisms might explain some of the link between suicide risk and brain circuitry and neurochemistry abnormalities. Results from a range of studies using diverse designs and post-mortem and in-vivo techniques show impairments of the serotonin neurotransmitter system and the hypothalamic-pituitary-adrenal axis stress-response system in the diathesis for suicidal behaviour. These impairments manifest as impaired cognitive control of mood, pessimism, reactive aggressive traits, impaired problem solving, over-reactivity to negative social signs, excessive emotional pain, and suicidal ideation, leading to suicidal behaviour. Biomarkers related to the diathesis might help to inform risk-assessment procedures and treatment choice in the prevention of suicide.

Differences between suicide attempters and nonattempters in depressed older patients: depression severity, white-matter lesions, and cognitive functioning

OBJECTIVES

The population of older adults with major depressive disorder (MDD) has the highest rate of suicide. White-matter brain lesions (WML) are a potential biologic marker for suicidality in young and middle-aged adults and are correlated with cognitive impairment in older adults. In this study of older patients with MDD, we examined 1) if a history of suicide attempts was associated with a more severe course of MDD; 2) if WML are a biologic marker for suicide; and 3) if suicide attempt history is associated with cognitive impairment mediated by WML.

SETTING

Data from the Neurocognitive Outcomes of Depression in the Elderly study.

PARTICIPANTS

Depressed patients (60+) who had ever attempted suicide (n = 23) were compared with depressed patients (60+) who had not attempted suicide (n = 223).

MEASUREMENTS

Baseline and follow-up assessments were obtained for depressive symptoms (every 3 months) and cognitive functioning (every 6 months) over 2 years. Three magnetic resonance imaging scans were conducted.

RESULTS

At baseline, suicide attempters reported more severe past and present symptoms (e.g., depressive symptoms, current suicidal thoughts, psychotic symptoms, earlier age of onset, and more lifetime episodes) than nonattempters. Suicide attempters had more left WML at baseline, and suicide attempt history predicted a greater growth in both left and right WML. WML predicted cognitive decline; nonetheless, a history of suicide attempt was unrelated to cognitive functioning.

CONCLUSIONS

Severity of depressive symptoms and WML are associated with suicide attempts in geriatric depressed patients. Suicide attempts predicted neurologic changes, which may contribute to poorer long-term outcomes in elder attempters.

Enlarged thalamic volumes and increased fractional anisotropy in the thalamic radiations in veterans with suicide behaviors

Post-mortem studies have suggested a link between the thalamus, psychiatric disorders, and suicide. We evaluated the thalamus and anterior thalamic radiations (ATR) in a group of Veterans with and without a history of suicidal behavior (SB) to determine if thalamic abnormalities were associated with an increased risk of SB. Forty Veterans with mild traumatic brain injury (TBI) and no SB (TBI-SB), 19 Veterans with mild TBI and a history of SB (TB + SB), and 15 healthy controls (HC) underwent magnetic resonance imaging scanning including a structural and diffusion tensor imaging scan. SBs were evaluated utilizing the Columbia Suicide Rating Scale and impulsivity was measured using the Barratt Impulsiveness Scale (BIS). Differences in thalamic volumes and ATR fractional anisotropy (FA) were examined between (1) TBI + SB versus HC and (2) TBI + SB versus combined HC and TBI-SB and (3) between TBI + SB and TBI-SB. Left and right thalamic volumes were significantly increased in those with TBI + SB compared to the HC, TBI-SB, and the combined group. Veterans with TBI + SB had increased FA bilaterally compared to the HC, HC and TBI-SB group, and the TBI-SB only group. Significant positive associations were found for bilateral ATR and BIS in the TBI + SB group. Our findings of thalamic enlargement and increased FA in individuals with TBI + SB suggest that this region may be a biomarker for suicide risk. Our findings are consistent with previous evidence indicating that suicide may be associated with behavioral disinhibition and frontal-thalamic-limbic dysfunction and suggest a neurobiologic mechanism that may increase vulnerability to suicide.

Total white matter hyperintensity volume in bipolar disorder patients and their healthy relatives

OBJECTIVES

White matter hyperintensities (WMH) are more common in subjects with bipolar disorder (BP) than in healthy subjects (HS). Few studies have examined the effect of the diagnostic type of bipolar illness on WMH burden, and none have approached this question through a direct measurement of the volume of affected white matter in relationship to familiality. In this pilot study, we utilized a volumetric measurement of WMH to investigate the relationship between the total volume of WMH and the familiality and type of BP.

METHODS

Forty-five individuals with bipolar I disorder (BP-I) with psychotic features, BP-I without psychotic features, or bipolar II disorder (BP-II), seven of their unaffected relatives, and 32 HS were recruited for participation. T-2 weighted magnetic resonance imaging scans were obtained on all subjects, and the total volume of all WMH for each subject was measured in cubic centimeters. The significance of difference between groups was tested using ANOVA with post-hoc adjustment for multiple comparisons. Further, we used logistic regression to test for trends between symptom load and total WMH volume.

RESULTS

The mean total volume of WMH in BP-I patients with psychotic features was significantly higher (p < 0.05) than that of HS. Further, we observed a positive linear trend by familiality and type of affectedness when comparing mean total WMH volume of HS, unaffected family members, subjects with BP-II, and BP-I with and without a history of psychosis (p < 0.05).

CONCLUSIONS

Based on a quantitative technique, WMH burden appears to be associated with familiality and type of BP. The significance of these findings remains to be fully elucidated.

White matter hyperintensities and self-reported depression in a sample of patients with chronic headache

White matter hyperintensities (WMH) have been associated with mood disorders in psychiatric patients. In the present study, we aimed to assess whether WMHs are associated with depressive symptoms and different sensitivity of the behavioral inhibition (BIS), and activation (BAS) systems in patients with chronic headache. Participants were 85 adult outpatients (16 men and 69 women) with a diagnosis of chronic headache. All of the patients underwent brain magnetic resonance imaging (MRI) and were administered the BIS/BAS scales and the Center for Epidemiologic Studies Depression Scale. Above 40 % of patients had periventricular WMHs (PWMHs) and almost 98 % had deep WMHs (DWMHs). Patients with PWMHs reported fewer depressive symptoms than patients without PWMHs. Patients with more severe DWMHs (compared with patients with mild or without DWMH lesions) were older and reported lower scores on the drive dimension of the BIS/BAS scales. In multivariate analyses, patients with PWMHs were 1.06 times more likely to report fewer depressive symptoms than patients without PWMHs. WMH lesions in patients with chronic headache were associated with less depression severity.

Relationship between suicidality and impulsivity in bipolar I disorder: a diffusion tensor imaging study

BACKGROUND

Impulsivity is characteristic of individuals with bipolar disorder and may be a contributing factor to the high rate of suicide in patients with this disorder. Although white matter abnormalities have been implicated in the pathophysiology of bipolar disorder, their relationship to impulsivity and suicidality in this disorder has not been well-investigated.

METHODS

Diffusion tensor imaging scans were acquired in 14 bipolar disorder patients with a prior suicide attempt, 15 bipolar disorder patients with no prior suicide attempt, and 15 healthy volunteers. Bipolar disorder patients received clinical assessments including measures of impulsivity, depression, mania, and anxiety. Images were processed using the Tract-Based Spatial Statistics method in the FSL software package.

RESULTS

Bipolar disorder patients with a prior suicide attempt had lower fractional anisotropy (FA) within the left orbital frontal white matter (p < 0.05, corrected) and higher overall impulsivity compared to patients without a previous suicide attempt. Among patients with a prior suicide attempt, FA in the orbital frontal white matter region correlated inversely with motor impulsivity.

CONCLUSIONS

Abnormal orbital frontal white matter may play a role in impulsive and suicidal behavior among patients with bipolar disorder.

The suicidal mind and brain: a review of neuropsychological and neuroimaging studies

OBJECTIVES. We aimed at reviewing studies exploring dysfunctional cognitive processes, and their neuroanatomical basis, in suicidal behaviour, and to develop a neurocognitive working model. Methods. A literature search was conducted. RESULTS. Several limitations were found. The main reported neuropsychological findings are a higher attention to specific negative emotional stimuli, impaired decision-making, lower problem-solving abilities, reduced verbal fluency, and possible reduced non-specific attention and reversal learning in suicide attempters. Neuroimaging studies mainly showed the involvement of ventrolateral orbital, dorsomedial and dorsolateral prefrontal cortices, the anterior cingulate gyrus, and, to a lesser extent, the amygdala. In addition, alterations in white matter connections are suggested. CONCLUSIONS. These studies support the concept of alterations in suicidal behaviour distinct from those of comorbid disorders. We propose that a series of neurocognitive dysfunctions, some with trait-like characteristics, may facilitate the development of a suicidal crisis during stressful circumstances: (1) an altered modulation of value attribution, (2) an inadequate regulation of emotional and cognitive responses, and (3) a facilitation of acts in an emotional context. This preliminary model may represent a framework for the design of future studies on the pathophysiology, prediction and prevention of these complex human behaviours.

Affective temperamental profiles are associated with white matter hyperintensity and suicidal risk in patients with mood disorders

BACKGROUND

Patients with white matter hyperintensities (WMH) may be at higher risk for affective disorders and suicide. Affective temperaments may play a significant role in mood disorders. This study aimed to evaluate the eventual association between WMH, affective temperaments and suicidal behaviour in major affective disorder.

METHODS

A total of 318 patients with major affective disorders were consecutively admitted as psychiatric inpatient. A total of 247 were included and given, brain magnetic resonance imaging (MRI) and assessed with the Mini International Neuropsychiatric Interview (MINI), the Beck Hopelessness Scale (BHS), the Hamilton Depression Rating Scale (HDRS(17)), the Young Mania Rating Scale (YMRS) and the Temperament Evaluation of Memphis, Pisa, Paris and San Diego (TEMPS-A).

RESULTS

A total of 48% of patients had periventricular WMH (PWMH) and 39% of them had deep WMH (DWMH). Patients with higher dysthymia and lower hyperthymia (H-DCIA group) were more likely to have higher BHS scores (BHS≥9=77% vs. 52%; p>0.001), more WMH (46% vs. 29%; χ(2)(n=3)=9.90; p<0.05), higher MINI suicidal risk (54% vs. 42%; p<0.05), and more recent suicide attempts (24% vs. 14%; p<0.05), than patients with higher hyperthymia and lower dysthymia (H-H group).

LIMITATIONS

The small sample size did not allow the generalization of the present findings.

CONCLUSIONS

Differences among temperament groups measured by the TEMPS-A are associated with differences in their MRIs, indicating that different temperament profiles are associated with differences in the subcortical structures of the brain. The implications of the results were discussed.

The prefrontal-limbic network in depression: Modulation by hypothalamus, basal ganglia and midbrain

The anterior cingulate cortex, amygdala and hippocampus form part of an interconnected prefrontal neocortical and limbic archicortical network that is dysregulated in major depressive disorders (MDD). Modulation of this prefrontal-limbic network (PLN) is principally through the hypothalamus, basal ganglia and midbrain. Here the likely mechanisms by which these modulations are affected are described and the implications of their failure for depression associated with suicidal diathesis, late-life and psychoses discussed.

The hypothalamic-pituitary-adrenal axis and serotonin abnormalities: a selective overview for the implications of suicide prevention

Suicidal behavior and mood disorders are one of the world's largest public health problems. The biological vulnerability for these problems includes genetic factors involved in the regulation of the serotonergic system and stress system. The hypothalamic-pituitary-adrenal (HPA) axis is a neuroendocrine system that regulates the body's response to stress and has complex interactions with brain serotonergic, noradrenergic and dopaminergic systems. Corticotropin-releasing hormone and vasopressin act synergistically to stimulate the secretion of ACTH that stimulates the biosynthesis of corticosteroids such as cortisol from cholesterol. Cortisol is a major stress hormone and has effects on many tissues, including on mineralocorticoid receptors and glucocorticoid receptors in the brain. Glucocorticoids produce behavioral changes, and one important target of glucocorticoids is the hypothalamus, which is a major controlling center of the HPA axis. Stress plays a major role in the various pathophysiological processes associated with mood disorders and suicidal behavior. Serotonergic dysfunction is a well-established substrate for mood disorders and suicidal behavior. Corticosteroids may play an important role in the relationship between stress, mood changes and perhaps suicidal behavior by interacting with 5-HT1A receptors. Abnormalities in the HPA axis in response to increased levels of stress are found to be associated with a dysregulation in the serotonergic system, both in subjects with mood disorders and those who engage in suicidal behavior. HPA over-activity may be a good predictor of mood disorders and perhaps suicidal behavior via abnormalities in the serotonergic system.

Vascular diseases and old age mental disorders: an update of neuroimaging findings

PURPOSE OF REVIEW

To review neuroimaging findings that have been reported in samples of patients with cardiovascular disorders and their association with the onset of Alzheimer's disease, vascular dementia, depression and bipolar disorder in the elderly and to highlight the implications of these findings to the knowledge about the pathophysiology of psychiatric disorders in old age, as well as their potential clinical implications.

RECENT FINDINGS

Vascular risk factors, such as hypertension, diabetes, dyslipidemia, smoking habits and heart failure, have all been associated with signs of cerebrovascular dysfunction, including structural MRI findings of signal hyperintensities, lacunes and stroke and functional imaging findings of brain regional hypoperfusion and hypometabolism. Such brain abnormalities have been found to increase the risk of onset of psychiatric disorder (depression, bipolar and dementia) in old age.

SUMMARY

As vascular risk factors are potentially modifiable when detected in midlife, the early characterization of brain changes associated with the presence of cardiovascular diseases holds promise to afford clinical applications in psychiatry, providing new perspectives for the prevention of old age psychiatric disorders.

Suicidal brains: a review of functional and structural brain studies in association with suicidal behaviour

Evidence of an association between a vulnerability to suicidal behaviour and neurobiological abnormalities is accumulating. Post-mortem studies have demonstrated structural and biochemical changes in the brains of suicide victims. More recently, imaging techniques have become available to study changes in the brain in vivo. This systematic review of comparative imaging studies of suicidal brains shows that changes in the structure and functions of the brain in association with suicidal behaviour are mainly found in the orbitofrontal and dorsolateral parts of the prefrontal cortex. Correlational studies suggest that these changes relate to neuropsychological disturbances in decision-making, problem solving and fluency, respectively. As a consequence, the findings from these studies suggest that suicidal behaviour is associated with (1) a particular sensitivity to social disapproval (2) choosing options with high immediate reward and (3) a reduced ability to generate positive future events. Further study is needed to elaborate these findings and to investigate to what extent changes in the structure and function of suicidal brains are amenable to psychological and/or biological interventions.

Cortical and subcortical abnormalities in late-onset depression with history of suicide attempts investigated with MRI and voxel-based morphometry

Late-onset major depression is thought to have a biological (vascular) basis, which could be a result of brain structure change. Vascular lesions can affect both the gray matter (GM) and white matter (WM), while most previous studies addressed WM abnormality. This study explored the disease- and symptom (history of suicide attempt) -related GM morphometry in elderly male patients with late-onset depression. A total of 70 patients with depression admitted to our geriatric psychiatric ward were investigated, and 26 age-matched males were recruited as controls. We used T1-weighted magnetic resonance imaging (MRI) to obtain cerebral structural information and adopted voxel-based morphometry (VBM) to investigate brain volume change related to disease (depression vs control) and symptom (depression with history of suicide attempt vs depression without history of suicide attempt). Late-onset depression was associated with smaller volumes in several regions of GM (insula and the posterior cingulate region) and WM (subcallosal cingulate cortex, floor of lateral ventricles, parahippocampal region, insula, and the cerebellum). Compared with nonsuicidal counterpart, suicidal depression was associated with decreased GM and WM volume in the frontal, parietal, and temporal regions, and the insula, lentiform nucleus, midbrain, and the cerebellum. Marked regional volume reduction was noticed at dorsal medial prefrontal cortex. Our results demonstrate that the development of suicidal behaviors in major depression is related to widespread but discrete volume reduction in several cortical and subcortical structures, fitting with the hypothesis that decreased cerebral volume in certain regions renders biological susceptibility to attempt suicide during depressive states.

Duration of untreated illness and suicide in bipolar disorder: a naturalistic study

The aim of this naturalistic study was to evaluate the potential influence of the duration of untreated illness (DUI)--defined as the time elapsed between the occurrence of the first mood episode and the first adequate pharmacological treatment with mood stabilizers--on the clinical course of bipolar disorder (BD). Three hundred and twenty outpatients (n = 320) with a DSM-IV diagnosis of BD--either Type I or Type II--were interviewed; their clinical features were collected and they were naturalistically followed-up for 5 years. At the end of the follow-up observation, the sample was subdivided into two groups: one group with a DUI < or =2 years (n = 65) and another group with a DUI >2 years (n = 255). The main demographic and clinical variables were analyzed and compared between the two subgroups of patients using chi-square tests for dichotomous variables or Mann-Whitney U tests for continuous variables. Patients with a longer DUI showed a higher frequency of suicide attempts (Z = -2.11, P = 0.035), a higher number of suicide attempters (chi(2) = 4.13, df = 1, P = 0.04), and a longer duration of illness (Z = -6.79, P < 0.0001) when compared to patients with a shorter DUI. Moreover, patients with a longer DUI had a depressive first episode more frequently than patients with a shorter DUI (chi(2) = 11.28, df = 2, P = 0.004). A further analysis performed dividing the total sample into two subgroups on the basis of a DUI of 6 years (corresponding to the median value of the DUI in the study sample) confirmed prior findings. Results indicate a potential association between a longer DUI and a worse outcome in BD, particularly in terms of suicidality, and confirm the clinical relevance of early diagnosis and pharmacological intervention with mood stabilizers in BD.

The structural neuroimaging of bipolar disorder

There is an increasing body of literature fuelled by advances in high-resolution structural MRI acquisition and image processing techniques which implicates subtle neuroanatomical abnormalities in the aetiopathogenesis of bipolar disorder. This account reviews the main findings from structural neuroimaging research into regional brain abnormalities, the impact of genetic liability and mood stabilizing medication on brain structure in bipolar disorder, and the overlapping structural deviations found in the allied disorders of schizophrenia and depression. The manifold challenges extant within neuroimaging research are highlighted with accompanying recommendations for future studies. The most consistent findings include preservation of total cerebral volume with regional grey and white matter structural changes in prefrontal, midline and anterior limbic networks, non-contingent ventriculomegaly and increased rates of white matter hyperintensities, with more pronounced deficits in juveniles suffering from the illness. There is increasing evidence that medication has observable effects on brain structure, whereby lithium status is associated with volumetric increase in the medial temporal lobe and anterior cingulate gyrus. However, research continues to be confounded by the use of highly heterogeneous methodology and clinical populations, in studies employing small scale, low-powered, cross-sectional designs. Future work should investigate larger, clinically homogenous groups of patients and unaffected relatives, combining both categorical and dimensional approaches to illness classification in cross-sectional and longitudinal designs in order to elucidate trait versus state mechanisms, genetic effects and medication/illness progression effects over time.

White matter hyperintensities and their association with suicidality in major affective disorders: a meta-analysis of magnetic resonance imaging studies

INTRODUCTION

Individuals who have deep and periventricular white matter hyperintensities may have a higher risk for suicidal behavior. There are mixed results in the literature regarding whether unipolar or bipolar patients who have attempted suicide have more deep white matter hyperintensities (DWMH) or periventricular hyperintensities (PVH) relative to those who have no history of suicide attempts.

METHODS

A meta-analysis of studies examining white matter hyperintensities (WMH) in mood disorder patients with and without a history of suicide attempts was performed.

RESULTS

Four studies, including a total of 173 patients who attempted suicide and 183 who did not attempt suicide, were included. A significantly higher number of attempters were found to have WMH than non-attempters. Unipolar depressed patients who had attempted suicide had 1.9 times more DWMH and 2.1 times more PVH than those who did not. Bipolar patients who had attempted suicide had 5.4 times more PVH than those who had not. Taken together, unipolar and bipolar patients who had attempted suicide had 2.8 times more DWMH and 4.5 times more PVH than those who had never attempted suicide.

CONCLUSION

These findings raise the possibility that WMH are biological substrates of symptoms that lead to suicidal behavior.

White matter lesions in euthymic patients with bipolar disorder

OBJECTIVE

We aimed to quantify both load and regional distributions of hyperintensities on magnetic resonance imaging (MRI) in prospectively verified euthymic bipolar patients and matched controls.

METHOD

Cerebral hyperintensities on T2, proton density and fluid-attenuated inversion recovery (FLAIR) MRI were compared between 48 bipolar and 47 control subjects using semi-quantitative rating scales.

RESULTS

Bipolar subjects had more severe frontal deep white matter lesions (DWML). Hyperintensity load was independent of age in bipolar patients but increased with age in controls. Global prevalence and severity of hyperintensities did not differ between groups. Exploratory analysis showed DWML in excess in the left hemisphere in bipolar subjects but not in controls.

CONCLUSION

Findings are consistent with clinical, particularly some neurocognitive, features of bipolar disorder and implicate fronto-subcortical circuits in its neurobiology. They more probably reflect a trait abnormality or illness scar rather than a mood state-dependent finding. Processes other than ageing and vascular factors may underlie their development.

Anterior genu corpus callosum and impulsivity in suicidal patients with bipolar disorder

Suicidality is a life-threatening symptom in patients with bipolar disorder (BD). Impulsivity and mood instability are associated with suicidality in mood disorders. Evidence suggests that gray and white matter abnormalities are linked with impulsivity in mood disorders, but little is known about the association between corpus callosum (CC) and impulsivity in BD. We examined the relationship between CC areas, impulsivity and suicidality in BD patients. We studied 10 female BD patients with a history of suicide attempt (mean+/-SD age 36.2+/-10.1 years), 10 female BD patients without suicide attempt history (44.2+/-12.5 years) and 27 female healthy subjects (36.9+/-13.8 years). Impulsivity was evaluated by the Barratt Impulsivity Scale (BIS). We traced MR images to measure the areas of the CC genu, anterior body, posterior body, isthmus and splenium. The genu was divided into anterior, middle and posterior regions. The suicidal and non-suicidal BD patients had significantly higher BIS total, attention and non-planning scores than the healthy subjects (ps<0.01), and the suicidal BD patients had significantly higher BIS motor scores than the non-suicidal BD and healthy subjects (ps<0.01). There were no significant differences among the three groups on any regional CC areas, although the suicidal BD patients had the smallest areas. The suicidal BD patients showed a significant inverse correlation between anterior genu area and the BIS total (r=-0.75, p=0.04), motor (r=-0.79, p=0.02) and non-planning scores (r=-0.79, p=0.02). These correlations were not found in the non-suicidal BD patients or healthy subjects. The results suggest that the anterior medial frontal region may be involved in the pathophysiology of impulsive and suicidal behaviors in BD.

Assessment and treatment of suicide risk in bipolar disorders

Completed suicide and suicide attempts are major issues in the management of bipolar disorders. There is evidence that suicide rates among these patients are more than 20-fold higher than the general population and, furthermore, suicidal behavior is much more lethal in bipolar disorder than in the general population. Patients with mood disorders may sometimes exhibit highly perturbed mixed states, which usually increase the risk of suicide. Such states are particularly frequent in bipolar II patients, especially if patients are treated with antidepressant monotherapy (unprotected by mood stabilizers), when depression switches into mania (or vice versa), or when depression lifts and functioning approaches normality. Researchers worldwide agree that treatment involving lithium is the best way to protect patients from suicide risk. Psychosocial activities, including psychoeducation, can protect bipolar patients either directly or, more probably, indirectly by increasing adherence to treatment and helping in daily difficulties that otherwise may lead to demoralization or hopelessness. An extensive understanding of the psychosocial circumstances and the psychopathology of bipolar patients (including temperament) may help clinicians describe the clinical picture accurately and prevent suicidal behavior in these patients.

Hyperintense MRI lesions in bipolar disorder: A meta-analysis and review

BACKGROUND

Cortical and subcortical hyperintensities in magnetic resonance imaging (MRI) scans are thought to represent areas of ischemic damage to brain tissue. Researchers have focused on the possible role these lesions may have in psychiatric disorders, including bipolar disorder. In 1997, the proposed 'vascular mania' diagnosis suggested utilizing not only the presence of strokes, but also confluent hyperintensities in its diagnostic criteria. This study was conducted to use meta-analytic techniques to investigate the association of hyperintensities and bipolar illness and to evaluate the current state of the literature.

METHODS

Using the PubMed and MEDLINE databases, we conducted a systematic literature search of studies investigating hyperintensities in subjects with bipolar disorder and controls or other psychiatric illnesses. We identified 44 publications from which 35 studies were included for review and 27 were selected for meta-analysis. Summary statistics of the prevalence were estimated through odds-ratios and confidence interval. Heterogeneity of the results across studies was tested using Q-statistics.

RESULTS

Meta-analysis identified an odds ratio of 2.5 (95% CI 1.9, 3.3) for hyperintensities in bipolar subjects compared to controls; however, there was significant heterogeneity among the studies (Q-statistics = 32; p = 0.04). This finding was most prominent for adolescents and children where the odds ratio was 5.7 (95% CI 2.3, 13.7). Deep white matter hyperintensities (odd ratio 3.2; 95% CI 2.2, 4.5) and subcortical grey matter hyperintensities (odds ratio 2.7; 95% CI 1.3, 2.9) were more strongly associated with bipolar subjects. There were no differences between bipolar subjects and controls for perivascular hyperintensities (odds ratio 1.3; 95% CI 0.8, 1.9). Though hyperintensities were numerically greater in bipolar subjects, meta-analysis did not demonstrate any significant differences between bipolar subjects and unipolar depression subjects (OR 1.6; 95% CI 0.9, 2.7) nor subjects with schizophrenia (OR 1.5; 95% CI 0.9, 2.7).

CONCLUSIONS

This meta-analysis continues to support the association of bipolar disorder and hyperintensities, especially in the deep white matter and subcortical grey matter. It also highlights the increased incidence in children and adolescence with bipolar disorder. However, hyperintensities are not specific to bipolar disorder, but appear at similar rates in unipolar depression and schizophrenia. Thus, the role of hyperintensities in the pathogenesis, pathophysiology, and treatment of bipolar disorder remains unclear. Further studies are required that are large enough to decrease the heterogeneity of the samples and MRI techniques, assess size and location of hyperintensities, and the impact on treatment response. Coordination with newer imaging techniques, such as diffusion tensor imaging (DTI) may be especially helpful in understanding the pathology of these lesions.

Neuroimaging genetics: new perspectives in research on major depression?

OBJECTIVE

Stress-related changes in the hippocampus are influenced by genetic factors. To enhance our understanding of both the interaction between the brain, behaviour and genetics and of biological mechanisms in mood disorders neuroimaging genetics provide a good opportunity.

METHOD

A MEDLINE search was conducted to identify articles on neuroimaging genetics in major depression (MD).

RESULTS

Hippocampal volumes were found to be associated with polymorphisms in the promotor region of the serotonin transporter (5-HTTLPR) in patients with MD. Met-allele carriers of the BDNF (val66met) polymorphism had smaller hippocampal volumes in both patients and healthy controls when compared with homozygous val-allele carriers. Polymorphisms of the serotonin transporter (5-HTTLPR) and 5-HT1a receptor are associated with increased amygdala activation investigated with functional MRI in patients with MD.

CONCLUSION

Genetic variants seem to modulate the effects of stress on hippocampal volumes as well as amygdala activity as well as the development of the brain.

Relationship of cerebrospinal fluid glucose metabolites to MRI deep white matter hyperintensities and treatment resistance in bipolar disorder patients

OBJECTIVES

Both diabetes mellitus and magnetic resonance image (MRI) deep white matter hyperintensities (WMHs) are more common in bipolar disorder (BD) patients than in matched controls. Deep-as opposed to periventricular--WMHs and diabetes are associated with treatment resistance and poorer outcome. This study investigated whether brain glucose metabolism by the polyol pathway--a pathway linked to nervous tissue disease in diabetes--is related to deep WMH volume and treatment resistance in BD patients.

METHODS

Volumes of fluid-attenuated inversion recovery WMHs were quantified and correlated with cerebrospinal fluid (CSF) concentrations of glucose metabolites in 20 nondiabetic patients with BD and nondiabetic comparison subjects with schizophrenia (n = 15) or transient neurologic symptoms (neurologic controls, n = 15).

RESULTS

BD patients, but not schizophrenic patients, had significantly greater volumes of deep but not periventricular WMHs compared to neurologic controls. BD subjects also had significantly greater CSF concentrations of sorbitol and fructose (the polyol pathway metabolites of glucose) compared to controls. Significant positive correlations between CSF metabolites and WMH volumes were found only in the BD group and were between deep WMH volumes and CSF sorbitol (rho = 0.487, p = 0.029) and fructose (rho = 0.474, p = 0.035). An index of treatment resistance correlated significantly with deep WMH volume (rho = 0.578, p = 0.008), sorbitol (rho = 0.542, p = 0.013), and fructose (rho = 0.692, p = 0.001) in BD subjects but not in other subjects.

CONCLUSIONS

This is the first reported evidence of relationships between abnormal brain glucose metabolism and both deep WMHs and treatment resistance in a group of BD patients. Further studies are necessary to determine the significance of these findings to BD pathophysiology.

Left orbitofrontal and superior temporal gyrus structural changes associated to suicidal behavior in patients with schizophrenia

Suicidal attempts are relatively frequent and clinically relevant in patients with schizophrenia. Recent studies have found gray matter differences in suicidal and non-suicidal depressive patients. However, no previous neuroimaging study has investigated possible structural abnormalities associated to suicidal behaviors in patients with schizophrenia. A whole-brain magnetic resonance voxel-based morphometric examination was performed on 37 male patients meeting the DSM-IV criteria for schizophrenia. Thirteen (35.14%) patients had attempted suicide. A non-parametric permutation test was computed to perform the comparability between groups. An analysis of covariance (AnCova) model was constructed with a statistical threshold of p<0.05 corrected for multiple comparisons. After controlling for age and severity of illness, results showed significant gray matter density reduction in left superior temporal lobe (p=0.03) and left orbitofrontal cortex (p=0.04) in patients who had attempted suicide when comparing with non-suicidal patients. Although sample size limitations and potential clinical heterogeneity preclude definitive conclusions, these data point to structural differences in key cerebral areas. Neuroimaging studies are necessary to expand our knowledge of biological mechanisms underlying suicide in schizophrenia.

Periventricular white matter hyperintensities as predictors of suicide attempts in bipolar disorders and unipolar depression

The aim of this study was to evaluate whether deep white matter hyperintensities (DWMH) and periventricular white matter hyperintensities (PVH) are associated with suicidal behavior in patients with major affective disorders. Subjects were 99 consecutively admitted inpatients (42 men; 57 women; mean age: 46.5 years [SD=15.2; Min./Max.=19/79]) with a diagnosis of major affective disorder (bipolar disorder type I, bipolar disorder type-II and unipolar major depressive disorder). 44.4% of the participants had made at least one previous suicide attempt. T2-weighted brain magnetic resonance images were rated for the presence and extension of WMH using the modified Fazekas scale. Patients were interviewed for clinical data on average 5 days after admission. Bivariate analyses, corrected for multiple-testing, and logistic regression analysis were used to test the association between suicide attempts and clinical variables. Attempters and nonattempters differed only in the presence of PVH--the former were more likely to have PVH. The logistic regression indicated that the presence of PVH was robustly associated with suicidal behaviors after controlling for age (OR: 8.08). In conclusion, neuroimaging measures may be markers of risk for suicidal attempts in patients with major affective disorders.

Early intervention in bipolar disorder, part I: clinical and imaging findings

The concept of prevention is not new to psychiatry and has long been recognized in general medicine. Recent evidence has highlighted that early pharmacological and psychosocial treatment dramatically ameliorates poor prognosis and outcome for individuals with psychotic disorders, reducing conversion rates to full-blown illness and decreasing symptom severity. Nevertheless, despite the many recent advances in our thinking about early intervention, the need for early intervention in bipolar disorder (BPD) is an area that has been relatively neglected. This review attempts to synthesize what is currently known about early intervention in BPD. We discuss methodological issues pertaining to this topic, review clinical studies that focus on high-risk subjects as well as first-episode patients and review findings from brain imaging studies in the offspring of individuals with BPD as well as in first-episode patients. A companion paper discusses the cellular and molecular mechanisms of action of agents with neurotrophic and neuroplastic properties, with a particular emphasis on lithium and valproate.

White matter hyperintensities in mid-adult life

PURPOSE OF REVIEW

White matter hyperintensities on T2-weighted magnetic resonance imaging are frequent incidental findings in the brains of elderly individuals. Recent studies have reported that they may also be common in middle-aged individuals, and their systematic evaluation in younger populations is necessary.

RECENT FINDINGS

Incidental white matter hyperintensities are common in brains of healthy individuals in their 60s and may be seen as early as the 30s and 40s. They are associated with subtle functional impairment and higher prevalence of neuropsychiatric disorders. While cerebrovascular risk factors such as hypertension, diabetes, high homocysteine, and so forth, are known risk factors for white matter hyperintensities, a significant proportion of the variance is unexplained. Genetic factors, alone or in interaction with environmental factors, appear to be important. There is a slight excess of white matter hyperintensities in women, the basis for which is not understood. Longitudinal studies show that those with baseline lesions have a greater progression over time.

SUMMARY

New imaging techniques present an opportunity to examine white matter pathology in great detail in younger populations. Standardized methods to examine such pathology and its determinants will help inform strategies for their prevention, which is an important component of a healthy ageing agenda.