Understanding impulsivity in severe depression? A psychometrical contribution

Rewiring the future: drugs abused in adolescence may predispose to mental illness in adult life by altering dopamine axon growth

Adolescence is a period of increased exploration and novelty-seeking, which includes new social behaviors, as well as drug experimentation, often spurred on by peer pressure. This is unfortunate, as the immature state of the adolescent brain makes it particularly susceptible to the negative developmental impact of drug use. During adolescence, dopamine terminals, which have migrated from the ventral tegmental area, pause in the nucleus accumbens, before segregating by either forming local connections or growing towards the prefrontal cortex (PFC). This developmentally late and lengthy process renders adolescent dopamine axon pathfinding vulnerable to disruption by substance use. Indeed, exposure to stimulant drugs in adolescent male mice, but not females, triggers dopamine axons to mistarget the nucleus accumbens and to grow ectopically to the PFC. Some evidence suggests that at this novel site, the functional organization of the ectopic dopamine axons mirrors that of the intended target. The structural rewiring dysregulates local synaptic connectivity, leading to poor impulse control ability, deficits of which are a core symptom of substance-use disorders. In the present commentary, we argue that different substances of abuse induce dopamine mistargeting events with the off-target trajectory prescribed by the type of drug, leading to psychiatric outcomes later in life.

Response inhibition related neural oscillatory patterns show reliable early identification of bipolar from unipolar depression in a Go/No-Go task

BACKGROUND

Response inhibition is a key neurocognitive factor contributing to impulsivity in mood disorders. Here, we explored the common and differential alterations of neural circuits associated with response inhibition in bipolar disorder (BD) and unipolar disorder (UD) and whether the oscillatory signatures can be used as early biomarkers in BD.

METHODS

39 patients with BD, 36 patients with UD, 29 patients initially diagnosed with UD who later underwent diagnostic conversion to BD, and 36 healthy controls performed a Go/No-Go task during MEG scanning. We carried out time-frequency and connectivity analysis on MEG data. Further, we performed machine learning using oscillatory features as input to identify bipolar from unipolar depression at the early clinical stage.

RESULTS

Compared to healthy controls, patients had reduced rIFG-to-pre-SMA connectivity and delayed activity of rIFG. Among patients, lower beta power and higher peak frequency were observed in BD patients than in UD patients. These changes enabled accurate classification between BD and UD with an accuracy of approximately 80 %.

CONCLUSIONS

The inefficiency of the prefrontal control network is a shared mechanism in mood disorders, while the abnormal activity of rIFG is more specific to BD. Neuronal responses during response inhibition could serve as a diagnostic biomarker for BD in early stage.

Indirect effect of impulsivity on suicide risk through self-esteem and depressive symptoms in a population with treatment-resistant depression: A FACE-DR study

INTRODUCTION

Suicide is a major health issue. Its prevalence is particularly high in subjects presenting major depression disorder (MDD), making this a key suicide-related risk factor. Suicide attempts in severe forms of MDD were assumed to be linked to impulsivity and loss of control. Nevertheless, we failed to find data specifically investigating the link between impulsivity and suicide risk in treatment-resistant depression (TRD). This study seeks to review this relationship.

METHOD

Patients were recruited for a prospective cohort. Suicide risk and impulsivity were assessed using the International Neuropsychiatric Interview and Barratt Impulsiveness Scale, Version 10, respectively, while the severity of depressive symptoms was assessed using the Montgomery-Asberg Depression Rating Scale, anxiety with the State-Trait Anxiety Inventory and childhood maltreatment using the Childhood Trauma Questionnaire.

RESULTS

220 TRD patients were enrolled in the study. The impulsivity score was correlated with self-esteem, marital status, professional status and anxiety. There was no direct link to suicide risk. However, impulsivity was associated with self-esteem (coefficient: -0.24; p value 0.043) and depressive symptom severity (coefficient: 0.; p value 0.045). The suicide risk was significantly correlated with depressive symptom severity (coefficient = 0.38, p < 0.001) and self-esteem (coefficient = -0.34, p = 0.01). Considering these correlations, we postulated that the effect of impulsivity on suicide risk could be mediated by self-esteem in terms of depressive symptom severity and we finally found a relevant mediation model within impulsivity having an indirect effect on suicide risk by impacting self-esteem and depressive symptoms with anxiety also playing a significant role as a covariable.

CONCLUSION

We found that impulsivity could play an indirect role with the involvement of self-esteem and depressive symptoms and the contributing role of anxiety.

A study on the functional near-infrared spectroscopy on impaired prefrontal activation and impulsivity during cognitive task in patients with major depressive disorder

BACKGROUND

This study aimed to examine the association between prefrontal activation during a verbal fluency task (VFT) and impulsivity among patients with major depressive disorder (MDD), using functional near-infrared spectroscopy (fNIRS).

METHODS

We enrolled a total of 119 participants, 60 with MDD patients and 59 with healthy controls (HCs), aged 18 to 34 years. The Barratt Impulsiveness Scale-11 (BIS-11) was used to assess impulsivity after completing baseline demographic, clinical, and physical assessments. A VFT was used to examine prefrontal activation during cognitive executions while fNIRS was monitored. The changing values of oxygenated hemoglobin (oxy-Hb) and their associations with the BIS-11 score were analyzed.

RESULTS

The data analysis comprised 109 participants in total (54 MDD; 55 HCs). Spearman's correlation analysis of the MDD group showed a negative correlation between changes in oxy-Hb and BIS-11 values in the right prefrontal cortex, notably the right frontopolar cortex (FPC) and ventromedial prefrontal cortex (VMPFC). After adjusting for sex, age, years of education, and Hamilton Depression Rating Scale (HAMD), significance was maintained in the right FPC [ρ = -0.317, p = 0.027], and the right VMPFC [ρ = -0.327, p = 0.022]. Furthermore, multivariate linear regression suggested a significant association in the right prefrontal cortex with BIS-11 score [β = -1.904, SE = 0.799, p = 0.0214].

CONCLUSIONS

Impaired prefrontal activation during a verbal fluency task, led to higher impulsivity in patients with MDD.

An exploratory study of functional brain activation underlying response inhibition in major depressive disorder and borderline personality disorder

Cognitive control is associated with impulsive and harmful behaviours, such as substance abuse and suicidal behaviours, as well as major depressive disorder (MDD) and borderline personality disorder (BPD). The association between MDD and BPD is partially explained by shared pathological personality traits, which may be underpinned by aspects of cognitive control, such as response inhibition. The neural basis of response inhibition in MDD and BPD is not fully understood and could illuminate factors that differentiate between the disorders and that underlie individual differences in cross-cutting pathological traits. In this study, we sought to explore the neural correlates of response inhibition in MDD and BPD, as well as the pathological personality trait domains contained in the ICD-11 personality disorder model. We measured functional brain activity underlying response inhibition on a Go/No-Go task using functional magnetic resonance imaging in 55 female participants recruited into three groups: MDD without comorbid BPD (n = 16), MDD and comorbid BPD (n = 18), and controls with neither disorder (n = 21). Whereas response-inhibition-related activation was observed bilaterally in frontoparietal cognitive control regions across groups, there were no group differences in activation or significant associations between activation in regions-of-interest and pathological personality traits. The findings highlight potential shared neurobiological substrates across diagnoses and suggest that the associations between individual differences in neural activation and pathological personality traits may be small in magnitude. Sufficiently powered studies are needed to elucidate the associations between the functional neural correlates of response inhibition and pathological personality trait domains.

The associations between suicide-related behaviors, prefrontal dysfunction in emotional cognition, and personality traits in mood disorders

Suicide is a serious public health problem, and it is urgent to identify biomarkers associated with suicide to prevent it. We aimed to clarify the association across suicidal behavior, personality traits, and brain activation by emotional stimulation tasks using near-infrared spectroscopy (NIRS) in patients with mood disorders. 11 mood disorder patients with a history of suicide attempt (MDSA), 18 mood disorder patients with no history of suicide attempt (MDNSA), and 17 healthy individuals were studied. The MDSA patients showed significantly high impulsivity and hopeless compared to healthy subjects, great response to the thread word task in the orbitofrontal cortex (OFC) and dorsolateral prefrontal cortex (DLPFC) compared to MDNSA patients, and the significant correlation between the personality traits and brain activation. The MDNSA did not show the trend. The results suggest that the personality traits and the activation of OFC and DLPFC during the negative emotional cognitive stimuli is associated with suicidal behavior, indicating the findings are involved in the pathophysiology of suicidality in mood disorders.

Social housing status impacts rhesus monkeys' affective responding in classic threat processing tasks

Individuals’ social contexts are broadly recognized to impact both their psychology and neurobiology. These effects are observed in people and in nonhuman animals who are the subjects for comparative and translational science. The social contexts in which monkeys are reared have long been recognized to have significant impacts on affective processing. Yet, the social contexts in which monkeys live as adults are often ignored and could have important consequences for interpreting findings, particularly those related to biopsychiatry and behavioral neuroscience studies. The extant nonhuman primate neuropsychological literature has historically tested individually-housed monkeys, creating a critical need to understand how social context might impact the outcomes of such experiments. We evaluated affective responding in adult rhesus monkeys living in four different social contexts using two classic threat processing tasks—a test of responsivity to objects and a test of responsivity to an unfamiliar human. These tasks have been commonly used in behavioral neuroscience for decades. Relative to monkeys with full access to a social partner, individually-housed monkeys had blunted reactivity to threat and monkeys who had limited contact with their partner were more reactive to some threatening stimuli. These results indicate that monkeys’ social housing contexts impact affective reactivity and point to the potential need to reconsider inferences drawn from prior studies in which the impacts of social context have not been considered.

Profiles of Teen Dating Violence and Association With Depression Among Chinese Teens

Teen dating violence (TDV) is a major global public health concern. Few studies, however, have examined profiles of TDV in Chinese societies and how these profiles might be associated with teens' mental health. The current study analyzed a sample of 891 middle and high school students with dating experience in Taiwan, Hong Kong, and Shanghai. Latent class analysis (LCA) and multinomial logit regression analysis were performed in an attempt to identify profiles of TDV and then investigate possible associations between class membership and self-reported depression. The results of LCA suggested that a four-class model was the best fit for the data: Severe/Multi-Type TDV (5.51%), Controlling Behavior (13.08%), Non/Low TDV (64.50%), and Physical Violence (16.91%). The best-fit model suggested bidirectionality, meaning among teen partners in an abusive relationship, both tended to participate in violent acts and controlling behaviors. The results of the multinomial regression showed that, compared with the Non/Low TDV class, teens in the Severe/Multi-Type TDV class or Controlling Behavior class had greater odds of screening positive for depression. There was no significant difference in the risk of depression between the Physical Violence class and the Non/Low TDV class. Implications for future research and practice are also discussed herein.

Irritability and Inattention Not Sad Low Mood Predict Impulsiveness in Children and Adolescents With Major Depressive Disorder and Persistent Depressive Disorder

ABSTRACT

The specific relationships between impulsiveness, inattention, sad, low mood, and irritability have not been systematically examined in young people with major depressive disorder with and without persistent depressive disorder. The relationships are important to clarify because these symptom dimensions may increase suicidal risk in children and adolescents with these depressive disorders. A total of 313 medication-naive young people (aged 6-16 years) with active major depressive disorder (MDD) alone, persistent depressive disorder (DD) alone, and comorbid MDD and DD were identified. "Inattention," "sad/unhappy," and "irritable" mood were identified by parent standardized questionnaire. Standard multiple regression was used to investigate how well inattention, sad/unhappy, and irritable mood predict impulsiveness. Inattention (32% of the variance, increased) and irritable mood (5% of the variance, increased) both made independent significant contributions to impulsiveness, whereas sad/unhappy mood did not. Decreasing irritability via more targeted and comprehensive management approaches may ameliorate impulsiveness in young people with these depressive disorders.

Temperament, character and decision-making characteristics of patients with major depressive disorder following a suicide attempt

BACKGROUND

Multiple psychological factors of suicidal behaviour have been identified so far; however, little is known about state-dependent alterations and the interplay of the most prominent components in a suicidal crisis. Thus, the combined effect of particular personality characteristics and decision-making performance was observed within individuals who recently attempted suicide during a major depressive episode.

METHODS

Fifty-nine medication-free major depressed patients with a recent suicide attempt (within 72 h) and forty-five healthy control individuals were enrolled in this cross-sectional study. Temperament and character factors, impulsivity and decision-making performance were assessed. Statistical analyses aimed to explore between-group differences and the most powerful contributors to suicidal behaviour during a depressive episode.

RESULTS

Decision-making and personality differences (i.e. impulsivity, harm avoidance, self-directedness, cooperativeness and transcendence) were observed between the patient and the control group. Among these variables, decision-making, harm avoidance and self-directedness were shown to have the strongest impact on a recent suicide attempt of individuals with a diagnosis of major depressive disorder according to the results of the binary logistic regression analysis. The model was significant, adequately fitted the data and correctly classified 79.8% of the cases.

CONCLUSIONS

The relevance of deficient decision-making, high harm avoidance and low self-directedness was modelled in the case of major depressed participants with a recent suicide attempt; meaning that these individuals can be described with the myopia for future consequences, a pessimistic, anxious temperament; and a character component resulting in the experience of aimlessness and helplessness. Further studies that use a within-subject design should identify and confirm additional characteristics specific to the suicidal mind.

Childhood Trauma increases suicidal behaviour in a treatment-resistant depression population: a FACE-DR report

OBJECTIVE

In addition to heredity, exposure to early-life adversity is an important predisposing risk factor of suicidal behaviour. Although the association between Childhood Trauma (CT) and suicide risk is well documented, interactions between CT and suicidal behaviour in Treatment-Resistant Depression (TRD) populations have received little coverage. This study aimed to evaluate i) association between CT and suicidal behaviour in a TRD population, and ii) the role of personality traits and impulsiveness as potential factors of mediation in these associations.

METHODS

Patients were recruited from a cohort of the French network of TRD expert centers. Depressive symptom severity, CT, suicidal behaviour, personality traits, and impulsiveness were assessed with the Montgomery-Åsberg Depression Rating Scale (MADRS), the Childhood Trauma Questionnaire (CTQ), the Columbia Suicide Severity Rating Scale (CSSRS), the Structured Clinical Interview for DSM-IV, the Big Five Inventory, and the Barratt Impulsivness Scale (BIS) respectively.

RESULTS

Among the 256 patients with a baseline CTQ, in relation to suicide risk for the current depressive episode, we found an association with the total CTQ scores mediated by the intensity of the current episode in a model adjusted for age and sex (total effect: β = 0.171; p = 0.011, direct effect: β = 0.135; p = 0.043; indirect effect: β = 0.036; p = 0.048). Focusing on CT subtypes, we detected an association between suicide risk and physical neglect in a model adjusted for age and sex (β = 0.301; p = 0.002), without any mediation by the intensity of the current episode. There was no mediation effect from personality traits nor impulsiveness. With regards to CSSRS to assess suicidal ideation, we did not find any association with the total CTQ score and CT subtype scores.

CONCLUSION

We report a strong association between suicidal behaviour and CT (in particular childhood physical neglect) in a TRD population.

Impulsivity as a multifactorial construct and its relationship to PTSD severity and threat sensitivity

Changes to the DSM-5's conceptualization of posttraumatic stress disorder (PTSD) highlight the importance of impulsivity within the context of PTSD-related arousal dysregulation. While the relationship between PTSD and threat sensitivity is well defined, how they relate to impulsivity remains understudied. We examined the relationship between PTSD symptom severity, threat sensitivity, and impulsivity. 124 participants completed the PTSD Checklist (PCL-C) and the Barratt Impulsiveness Scale 11th ed (BIS-11). BIS-11 items were separated to define cognitive and behavioral impulsivity subdomains. A trauma-exposed subsample of 39 participants were also exposed to no, ambiguous, and high threat conditions in a threat-enhanced acoustic startle paradigm with psychophysiological response as the outcome variable. PTSD severity was significantly associated with greater overall impulsivity and behavioral impulsivity. Greater overall impulsivity and both cognitive and behavioral impulsivity subdomains were significantly associated with psychophysiological magnitudes across threat conditions in the traumatized subsample. Our results suggest PTSD severity may linked to behavioral impulsivity and both cognitive and behavioral impulsivity are associated with threat sensitivity and hyperarousal. Assessing impulsivity within the context of PTSD, particularly in terms of its cognitive and behavioral subdomains, may provide important, clinically relevant information.

Contribution of sex on the underlying mechanism of the gambling disorder severity

Significant increasing prevalences have been observed in gambling disorder (GD) in the last decades. This study analyzed the underlying mechanisms of the gambling severity with path analysis (implemented through Structural Equation Modeling, SEM), and assessed the potential moderator effect of the patients’ sex. A sample of n = 512 treatment-seeking patients was assessed for sociodemographics and clinical state previously to the treatment. Results obtained in two separate SEM (for men and women) revealed differences in the direct effects and the mediational links. Among the male subsample, higher GD severity was directly related to the higher cognitive bias and the younger age of onset of the problematic gambling, while impulsivity levels and age of onset achieved an indirect effect on the disordered gambling mediated by the cognitive bias. Among females, GD severity was directly increased by younger age of onset, higher cognitive bias and lower self-directedness, while lower socioeconomic positions, and higher levels in harm avoidance achieved an indirect effect on the gambling severity mediated also by the distortions related to the gambling activity. These results provide new empirical evidence for a better understanding of the GD etiology, suggesting that the underlying complex links mediating the GD severity are strongly related to the patients’ sex. The results can also contribute to design more effectiveness and precise therapy programs of patient-centered care.

Impulsiveness, personality traits and executive functioning in patients with juvenile myoclonic epilepsy

PURPOSE

To evaluate impulsiveness in adult patients with JME and its relationship with personality traits and executive functioning.

METHODS

Patients completed psychiatric evaluation (DSM IV), Barratt Impulsiveness Scale (BIS-11), Neo Revised Personality Inventory (NEO PI-R) and executive functioning evaluation comprising Controlled Oral Word Association (COWA), Digit Span, Trail Making Tests (TMT), Stroop Test (ST) and Wisconsin Card Sorting Test (WSCT). Healthy controls (63 % female, mean age 35.7 yrs. (±8.37)) were examined to allow calculation of z-scores.

RESULTS

50 patients (70 % female; mean age 32.5 yrs. (±9.2)) presented higher scores of Total (z=-0.37; p = 0.005) and Motor Impulsiveness (z=-0.79; p < 0.001) on BIS-11. Motor Impulsiveness was associated with higher rates of mild psychiatric disorders (depression and anxiety) (p = 0.035) and worse myoclonic seizure control (p = 0.007). NEO PI-R showed differences on Neuroticism (z=-0.60; p < 0.001), Openness (z = 0.38; p = 0.043), Agreeableness (z=-0.38; p = 0.033) and Conscientiousness (z=-0.53; p = 0.003). There were positive correlations between BIS-11 and Neuroticism with Total, Motor and Non-Planning Impulsiveness, on the other hand, Conscientiousness was negatively correlated with these as well as with Attentive Impulsiveness. Patients performance was worse than that of controls on COWA (z=-0.43; p = 0.009) and WCST's Total Number of Completed Categories (z=-2.08; p = 0.005), Trials Taken to Complete First Category (z=-1.56; p = 0.013), Percentage of Total Errors (z=-1.56; p < 0.001), Perseverative Errors (z=-0.73; p = 0.002), Non-Perseverative Errors (z=-1.05; p = 0.003) and Conceptual Level Responses (z=-1.52; p < 0.001). Non-Planning Impulsiveness correlated with Performance (ST and TMT).

CONCLUSION

Patients with JME present with impulsive behavior, personality features and executive dysfunction which are linked and may lead to lack of commitment in treatment and affect other aspects of life.

Serum Lipids among Drug Naïve or Drug-Free Patients with Obsessive Compulsive Disorder and their Association with Impulsivity: A Comparative Study

BACKGROUND

The derangement of serum lipids is well documented in psychiatric disorders like schizophrenia, mania, and depression but not in obsessive compulsive disorder (OCD), where it has been inadequately examined. Also, serum lipid abnormalities are increasingly found in "impulsivity," an important sub-construct of OCD. Our study aimed to examine serum lipid profile among patients with OCD and its association with clinical profile and impulsivity among them.

METHODS

Forty drug naïve or drug-free (four weeks for oral and eight weeks for any depot psychotropics) patients with OCD according to International Classification of Disease -10th version (ICD-10): Diagnostic Criteria for Research (DCR) by the World Health Organization (WHO), from outpatient and inpatient departments of a tertiary care psychiatric hospital were recruited. Measures like Yale-Brown Obsessive Compulsive Scale (Y-BOCS), Hamliton Rating Scale for Depression (HAM-D), Barratt's Impulsivity Scale (BIS-11), and Hamilton Rating Scale for Anxiety (HAM-A) were administered. Forty age and sex-matched healthy controls (HC) were recruited after screening with General Health Questionnaire 12 (GHQ-12). Serum lipids were assessed in both the groups.

RESULTS

Serum high density lipoproteins (HDL) (P < 0.001; partial η2 = 0.176) and apolipoprotein B (P < 0.001; partial η2 = 0.531) were significantly higher in OCD group than age- and sex-matched HC. A trend toward lower serum HDL (P = 0.06; partial η2 = 0.060) was observed among patients of OCD with high impulsivity. Serum HDL was negatively correlated with BIS attention (rs =-0.32; p = 0.03), BIS motor (rs = 0.40; P = 0.01), BIS non-planning (rs = - 0.36; P = 0.02), and BIS total (rs = - 0.36; P = 0.01) scores. Serum triglycerides (TG) (rs = 0.34; P = 0.03) and apolipoprotein B (rs = -0.32; P = 0.04) were negatively correlated with Y-BOCS compulsion score. Serum TG (rs = -0.45, P < 0.01) and serum very low density lipoprotein (VLDL) was negatively (rs = -0.39; P = 0.01) correlated with Y-BOCS total scores. Serum VLDL was positively (rs = 0.34; P = 0.03) correlated with BIS motor scores.

CONCLUSIONS

Serum lipid fractions are deranged among patients with OCD. Different lipid fractions have different associations with clinical profiles of OCD. Impulsivity among patients with OCD may have a specific association with serum lipids. A small sample size, use of self-report measure without adaptation for impulsivity, a lack of metabolic profile assessment among participants, and a lack of assessment of impulsivity among HC were the limitations of our tudy.

Impulsivity, personality and bipolar disorder

Background

Increased impulsivity is a diagnostic feature of mania in bipolar disorder (BD). However it is unclear whether increased impulsivity is also a trait feature of BD and therefore present in remission. Trait impulsivity can also be construed as a personality dimension but the relationship between personality and impulsivity in BD has not been explored. The aim of this study was to examine the relationship of impulsivity to clinical status and personality characteristics in patients with BD.

Methods

We measured impulsivity using the Barratt Impulsiveness Scale (BIS-11) and personality dimensions using Eysenck Personality Questionnaire in 106 BD patients and demographically matched healthy volunteers. Clinical symptoms were assessed in all participants using the Clinical Global Impressions Scale, the Montgomery-Asberg Depression Rating Scale and the Young Mania Rating Scale. Based on their clinical status patients were divided in remitted (n = 36), subsyndromal (n = 25) and syndromal (n = 45).

Results

There was no difference in BIS-11 and EPQ scores between remitted patients and healthy subjects. Impulsivity, Neuroticism and Psychoticism scores were increased in subsyndromal and syndromal patients. Within the BD group, total BIS-11 score was predicted mainly by symptoms severity followed by Psychoticism and Neuroticism scores.

Conclusions

Increased impulsivity may not be a trait feature of BD. Symptom severity is the most significant determinant of impulsivity measures even in subsyndromal patients.

Do Suicide Attempts of Mood Disorder Patients Directly Increase the Risk for a Reattempt?

Background: Preceding suicide attempts strongly predict future suicidal acts. However, whether attempting suicide per se increases the risk remains undetermined. We longitudinally investigated among patients with mood disorders whether after a suicide attempt future attempts occur during milder depressive states, indicating a possible lowered threshold for acting. Methods: We used 5-year follow-up data from 581 patients of the Jorvi Bipolar Study, Vantaa Depression Study, and Vantaa Primary Care Depression Study cohorts. Lifetime suicide attempts were investigated at baseline and during the follow-up. At follow-up interviews, life-chart data on the course of the mood disorder were generated and suicide attempts timed. By using individual-level data and multilevel modeling, we investigated at each incident attempt the association between the lifetime ordinal number of the attempt and the major depressive episode (MDE) status (full MDE, partial remission, or remission). Results: A total of 197 suicide attempts occurred among 90 patients, most during MDEs. When the dependencies between observations and individual liabilities were modeled, no association was found between the number of past suicide attempts at the time of each attempt and partial remissions. No association between adjusted inter-suicide attempt times and the number of past attempts emerged during follow-up. No indication for direct risk-increasing effects was found. Conclusion: Among mood disorder patients, repeated suicide attempts do not tend to occur during milder depressive states than in the preceding attempts. Previous suicide attempts may indicate underlying diathesis, future risk being principally set by the course of the disorder itself.

Temporal Preparation, Impulsivity and Short-Term Memory in Depression

Patient suffering of major depressive disorder (MDD) often complain that subjective time seems to "drag" with respect to physical time. This may point toward a generalized dysfunction of temporal processing in MDD. In the present study, we investigated temporal preparation in MDD. "Temporal preparation" refers to an increased readiness to act before an expected event; consequently, reaction time should be reduced. MDD patients and age-matched controls were required to make a saccadic eye movement between a central and an eccentric visual target after a variable duration preparatory period. We found that MDD patients produced a larger number of premature saccades, saccades initiated prior to the appearance of the expected stimulus. These saccades were not temporally controlled; instead, they seemed to reflect reduced inhibitory control causing oculomotor impulsivity. In contrast, the latency of visually guided saccades was strongly influenced by temporal preparation in controls; significantly less so, in MDD patients. This observed reduced temporal preparation in MDD was associated with a faster decay of short-term temporal memory. Moreover, in patients producing a lot of premature responses, temporal preparation to early imperative stimuli was increased. In conclusion, reduced temporal preparation and short-term temporal memory in the oculomotor domain supports the hypothesis that temporal processing was altered in MDD patients. Moreover, oculomotor impulsivity interacted with temporal preparation. These observed deficits could reflect other underlying aspects of abnormal time experience in MDD.

Prefrontal Asymmetry during Cognitive Tasks and its Relationship with Suicide Ideation in Major Depressive Disorder: An fNIRS Study

Reduced oxygenation changes in the prefrontal cortex during cognitive tasks have been reported in major depressive disorder (MDD). However, prefrontal asymmetry during cognitive tasks and its relation to suicide ideations have been less frequently examined in patients with MDD. This study investigated prefrontal asymmetry and its moderating effect on the relationship between depression severity and suicidal ideation in MDD patients during cognitive tasks. Forty-two patients with MDD and 64 healthy controls (HCs) were assessed for changes in oxygenated and deoxygenated hemoglobin (Hb) in the prefrontal cortex using functional near-infrared spectroscopy (fNIRS) during the verbal fluency task (VFT), Stroop task, and two-back task. Depression, anxiety, and suicide ideation were measured through self-report questionnaires. Relatively smaller left oxy-Hb changes during VFT, but not during the Stroop or two-back tasks, were found in MDD patients compared with HCs. Furthermore, prefrontal asymmetry during VFT moderated the effect of depression severity on suicide ideation, and was significantly and positively correlated with suicide ideation in patients with MDD. Specifically, relatively greater left oxy-Hb changes were associated with greater suicide ideation. These findings suggest fNIRS-measured prefrontal asymmetry as a potential biomarker for MDD and for the assessment of suicidal risk in patients with MDD.

The relationship between impulsivity and shame and guilt proneness on the prediction of internalizing and externalizing behaviors

Shame and guilt are responses to moral transgressions that are characterized by negative self-evaluations and negative behavioral-evaluations, respectively. Previous research has found shame to be the more maladaptive of these “self-conscious” emotions due to its association with various health-risk behaviors. In the current study, undergraduate participants (n = 199) from a large, public university completed behavioral and self-report measures of impulsivity, shame and guilt-proneness, and behavioral tendencies. Exploratory factor analysis and mediation models were used to determine if shame and/or guilt-proneness significantly mediate the relationship between impulsivity and internalized/externalized problems. Findings demonstrate that impulsivity and shame proneness both positively predict internalized and externalized problem behavior, but indirect effects of shame and guilt are not significant. These findings indicate that shame and guilt do not reliably mediate the relationship between impulsivity and problem behavior, but they do support previous findings on the maladaptive nature of impulsivity and shame. Implications for the protective nature of guilt proneness are also discussed.

Lack of Emotional Awareness is Associated with Thwarted Belongingness and Acquired Capability for Suicide in a Military Psychiatric Inpatient Sample

OBJECTIVE

To examine potential links between facets of impulsivity and emotion dysregulation to components of the Interpersonal-Psychological Theory of Suicide (thwarted belongingness, perceived burdensomeness, and acquired capability) among U.S. military personnel.

METHOD

The current study performed secondary data analysis from a randomized control trial testing the efficacy of a cognitive therapy for 134 service members (71.64% male, 68.66% Caucasian; mean age: 30.14) admitted to a psychiatric inpatient unit for a suicide-related crisis. We utilized the Difficulties in Emotion Regulation Scale, the Barratt Impulsivity Scale, the Acquired Capability for Suicide Scale, and the Interpersonal Needs Questionnaire.

RESULTS

All emotion dysregulation dimensions and one impulsivity facet (attentional) were positively correlated with perceived burdensomeness and thwarted belongingness. Lack of emotional awareness was positively associated with acquired capability. After controlling for depression, hopelessness, and demographic covariates, lack of emotional awareness was significantly associated with both thwarted belongingness and acquired capability, but not perceived burdensomeness, and impulsivity dimensions did not link to any variable of interest.

CONCLUSIONS

Findings imply that individuals with reduced emotional awareness may have difficulty cultivating interpersonal bonds and be more vulnerable to elevated acquired capability. Lack of emotional awareness may be a potential contributor to both suicidal desire and capability.

Severity and Variability of Depression Symptoms Predicting Suicide Attempt in High-Risk Individuals

IMPORTANCE

Predicting suicidal behavior continues to be among the most challenging tasks in psychiatry.

OBJECTIVES

To examine the trajectories of clinical predictors of suicide attempt (specifically, depression symptoms, hopelessness, impulsivity, aggression, impulsive aggression, and irritability) for their ability to predict suicide attempt and to compute a risk score for suicide attempts.

DESIGN, SETTING, AND PARTICIPANTS

This is a longitudinal study of the offspring of parents (or probands) with mood disorders who were recruited from inpatient units at Western Psychiatric Institute and Clinic (Pittsburgh) and New York State Psychiatric Institute. Participants were recruited from July 15, 1997, to September 6, 2005, and were followed up through January 21, 2014. Probands and offspring (n = 663) were interviewed at baseline and at yearly follow-ups for 12 years. Lifetime and current psychiatric disorders were assessed, and self-reported questionnaires were administered. Model evaluation used 10-fold cross-validation, which split the entire data set into 10 equal parts, fit the model to 90% of the data (training set), and assessed it on the remaining 10% (test set) and repeated that process 10 times. Preliminary analyses were performed from July 20, 2015, to October 5, 2016. Additional analyses were conducted from July 26, 2017, to July 24, 2018.

MAIN OUTCOMES AND MEASURES

The broad definition of suicide attempt included actual, interrupted, and aborted attempts as well as suicidal ideation that prompted emergency referrals during the study. The narrow definition referred to actual attempt only.

RESULTS

The sample of offspring (n = 663) was almost equally distributed by sex (316 female [47.7%]) and had a mean (SD) age of 23.8 (8.5) years at the time of censored observations. Among the 663 offspring, 71 (10.7%) had suicide attempts over the course of the study. The trajectory of depression symptoms with the highest mean scores and variability over time was the only trajectory to predict suicide attempt (odds ratio [OR], 4.72; 95% CI, 1.47-15.21; P = .01). In addition, we identified the following predictors: younger age (OR, 0.82; 95% CI, 0.74-0.90; P < .001), lifetime history of unipolar disorder (OR, 4.71; 95% CI, 1.63-13.58; P = .004), lifetime history of bipolar disorder (OR, 3.4; 95% CI, 0.96-12.04; P = .06), history of childhood abuse (OR, 2.98; 95% CI, 1.40-6.38; P = .01), and proband actual attempt (OR, 2.24; 95% CI, 1.06-4.75; P = .04). Endorsing a score of 3 or higher on the risk score tool resulted in high sensitivity (87.3%) and moderate specificity (63%; area under the curve = 0.80).

CONCLUSIONS AND RELEVANCE

The specific predictors of suicide attempt identified are those that clinicians already assess during routine psychiatric evaluations; monitoring and treating depression symptoms to reduce their severity and fluctuation may attenuate the risk for suicidal behavior.

Factors linking suicidal ideation with drinking to cope and alcohol problems in emerging adult college drinkers

There is a well-established association between suicidal behavior and alcohol misuse. However, few studies have applied relevant theory and research findings in the areas of both alcohol and suicidal behavior to aid in the understanding of why these may be linked. The current study examined whether three variables (problem-solving skills, avoidant coping, and negative urgency) suggested by theory and previous findings in both areas of study help to account for the previously found association of suicidal ideation with drinking to cope and alcohol problems. Participants were 381 college women (60.4%) and men (39.6%) between the ages of 18 and 25 who were current drinkers and had a history of (at a minimum) passive suicidal ideation. Structural equation modeling was used to examine hypothesized associations among problem-solving skills, avoidant coping, drinking to cope (DTC), impulsivity in response to negative affect (i.e., negative urgency), severity of suicidal ideation, heavy alcohol use, and alcohol problems. Model results revealed that problem-solving skills deficits, avoidant coping, and negative urgency were each directly or indirectly associated with greater severity of suicidal ideation, DTC, heavy alcohol use, and alcohol problems. The results suggest that the positive association between suicidal ideation and DTC found in this and other studies may be accounted for by shared associations of these variables with problem-solving skills deficits, avoidant coping, and negative urgency. Increasing at-risk students' use of problem-solving skills may aid in reducing avoidance and negative urgency, which in turn may aid in reducing suicidal ideation, DTC, and alcohol misuse. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Impulsivity differences between bipolar and unipolar depression

BACKGROUND

Even though particularly bipolar depression and unipolar depression seem to be similar, they show differences in terms of the etiology, phenomenology, course, and treatment process. Bipolar depression is associated with mood lability, motor retardation, and hypersomnia to a larger extent. Early age of onset, a high frequency of depressive episodes, and history of bipolar disease in the family are suggestive of bipolar disorder (BD) rather than major depression. Bipolar and unipolar disorders are also associated with increased impulsivity during illness episodes. However, there is little information about impulsivity during euthymia in these mood disorders. The aim of this study was to illustrate the difference in impulsivity in euthymic bipolar and unipolar patients.

MATERIALS AND METHODS

Impulsivity was evaluated by the Barratt Impulsiveness Scale (BIS-11A), in 78 interepisode BD patients, 72 interepisode unipolar disorder patients, and 70 healthy controls. The diagnosis was established by severe combined immunodeficiency. One-way between-groups ANOVA was used to compare the BIS-11A mean scores for all three groups.

RESULTS

Impulsivity scores of the bipolar and unipolar disorder patients were significantly higher than controls on total and all subscales measures. There was no difference between the bipolar and unipolar disorder groups on total, attentional, and nonplanning impulsivity measures. However, BD patients scored significantly higher than the unipolar patients on motor impulsivity measures.

CONCLUSIONS

Both interepisode bipolar and unipolar disorder patients had increased impulsivity compared to healthy individuals. There was no significant difference on attention and nonplanning impulsivity subscales; however, on the motor subscale, bipolar patients were more impulsive than unipolar disorder patients.

Gambling-related cognitive distortions mediate the relationship between depression and disordered gambling severity

BACKGROUND AND OBJECTIVES

Symptoms of depression are highly prevalent among individuals with gambling disorder, and severity of depression is associated with severity of gambling problem. Yet, little is known about the psychological mechanisms by which symptoms of depression lead to greater gambling severity. In this study, we tested whether cognitive distortions represent one such mechanism, as cognitive distortions are key characteristics in both depression and gambling disorder and have been shown to be associated with gambling severity.

METHODS

A mediation model was tested among 345 treatment-seeking individuals with gambling disorder in Sao Paulo, Brazil. The diagnosis of gambling disorder was made using semi-structured clinical interviews and participants completed psychometrically sound self-report measures of depression symptoms (Beck Depression Inventory-I), gambling-related cognitive distortions (Gamblers' Beliefs Questionnaire), and gambling severity (Gambling Symptom Assessment Scale).

RESULTS

As hypothesized, increased symptoms of depression were significantly associated with both increased disordered gambling severity and increased gambling-related cognitive distortions. Further, gambling-related cognitive distortions predicted greater disordered gambling severity when controlling for depression symptomology. Results from the bootstrapping method indicated that the relationship between symptoms of depression and increased disordered gambling severity is mediated by gambling-related cognitive distortions.

CONCLUSIONS

Consistent with our predictions, gambling-related cognitive distortions mediated the relationship between depression symptoms and gambling severity among a sample of treatment-seeking disordered gamblers. These results suggest that cognitive distortions may be a key intervention target for the treatment of concurrent depression and gambling disorder.

Cerebrospinal fluid FGF23 levels correlate with a measure of impulsivity

Fibroblast growth factor 23 (FGF23) is a bone-derived protein produced mainly by osteocytes and osteoblasts and at low levels in specific parts of the brain. It has been shown to associate with mood regulation. Lithium treatment gives rise to significant elevations of serum FGF23 levels in depressive patients. High peripheral blood FGF23 levels correlated with poor cognitive performance in hemodialysis patients. However, no direct evidence demonstrates a relationship between FGF23 and mood regulation. In this study, we aimed to measure the concentration of cerebrospinal fluid (CSF) FGF23 and to explore its relationship with a cluster of emotional characteristics. We measured CSF FGF23 levels in 96 male Chinese subjects. All subjects completed the Chinese version of the Barratt Impulsiveness Scale (BIS 11), the Beck Depression Inventory (BDI) and the Self-Rating Anxiety Scale (SAS). CSF FGF23 levels ranged from 12.8 to 99.3 pg/mL. Negative correlations were found between CSF FGF23 concentrations and BIS non-planning, BIS cognition and BIS total score (all p < 0.05). Nevertheless, except for the BIS cognition scores, these correlations became insignificant after Bonferroni correction. No correlations were found between CSF FGF23 concentrations and BDI or SAS scores. These findings suggest that CSF FGF23 levels correlate with a measure of impulsivity.

Impulsivity as a mediator in the relationship between problem solving and suicidal ideation

OBJECTIVE

This study examined whether three facets of impulsivity previously shown to be associated with suicidal ideation and attempts (negative urgency, lack of premeditation, and lack of perseverance) help to account for the established association between problem solving deficits and suicidal ideation.

METHOD

Emerging adult college student drinkers with a history of at least passive suicidal ideation (N = 387) completed measures of problem solving, impulsivity, and suicidal ideation. A path analysis was conducted to examine the mediating role of impulsivity variables in the association between problem solving (rational problem solving, positive and negative problem orientation, and avoidance style) and suicidal ideation.

RESULTS

Direct and indirect associations through impulsivity, particularly negative urgency, were found between problem solving and severity of suicidal ideation.

CONCLUSIONS

Interventions aimed at teaching problem solving skills, as well as self-efficacy and optimism for solving life problems, may help to reduce impulsivity and suicidal ideation.

Relationship of PTSD With impulsivity Dimensions While Controlling the Effect of Anxiety and Depression in a Sample of Inpatients With Alcohol Use Disorder

OBJECTIVE

The aim of the present study was to evaluate the relationship of posttraumatic stress disorder (PTSD) with impulsivity dimensions while controlling the effect of anxiety and depression in a sample of inpatients with alcohol use disorder (AUD).

METHODS

Participants were 190 male patients admitted to a specialized center for substance use disorders within a six month period. Participants were evaluated with the State-Trait Anxiety Inventory (STAI), Beck Depression Inventory (BDI), the Short Form Barratt Impulsiveness Scale (BIS-11-SF), the Traumatic Experiences Checklist, and PTSD Checklist-Civilian version.

RESULTS

Age was lower in the group with PTSD (n = 63, 33.2%) than the group without PTSD (n = 127, 66.8%). Duration of education, marital, and employment status did not differ between the groups. STAI, BDI, and BIS-11-SF scores were higher in the group with PTSD. Trait anxiety, depression, and impulsivity predicted high PTSD risk in a logistic regression model. Same variables predicted the severity of PTSD symptoms in a linear regression. Among dimensions of impulsivity attentional component was the only predictor of PTSD symptoms severity, not motor or nonplanning impulsivity.

CONCLUSIONS

These findings suggest that the PTSD may be related to impulsivity, particularly attentional impulsivity, even after controlling anxiety and depression among inpatients with AUD.

Examination of the heterogeneity in PTSD and impulsivity facets: A latent profile analysis

The experience of traumatizing events and resulting posttraumatic stress disorder (PTSD) symptomology relates to a range of impulsive behaviors. While both PTSD and impulsivity are heterogeneous and multidimensional constructs, no research has used person-centered approaches to examine subgroups of individuals based on these response endorsements. Hence, our study examined PTSD-impulsivity typologies and their construct validity in two samples: university students (n = 412) and community participants recruited through Amazon's MTurk (n = 346). Measures included the Stressful Life Events Screening Questionnaire (PTEs), PTSD Checklist for DSM-5 (PTSD severity), UPPS Impulsive Behavior Scale (negative urgency, lack of premeditation, lack of perseverance, sensation seeking). Dimensions of Anger Reaction Scale (anger), and the Patient Health Questionnaire-9 (depression). For both samples, results of latent profile analyses indicated a best-fitting 3-class solution: High, Moderate, and Low PTSD-Negative Urgency. Negative urgency was the most distinguishing impulsivity facet. Anger and depression severity significantly predicted membership in the more severe symptomatology classes. Thus, individuals can be meaningfully categorized into three subgroups based on PTSD and impulsivity item endorsements. We provide some preliminary evidence for a negative urgency subtype of PTSD characterized by greater depression and anger regulation difficulties; and underscore addressing emotional regulation skills for these subgroup members.

Gender differences in exposure and vulnerability to psychosocial and behavioral factors of suicide attempt among Korean adolescents

INTRODUCTION

This study examined gender differences in suicide attempts and their association with exposure and vulnerability to psychosocial, behavioral, and structural factors among Korean adolescents.

METHODS

Data of 74 854 adolescents, taken from the 2010 Korea Youth Risk Behavior Survey, were used. Logistic regression analysis was used to assess the contribution of differential exposure to psychosocial, behavioral, and structural factors for gender differences of suicidal attempt.

RESULTS

Gender differences were observed in the degree of exposure to the various factors. Females were more likely to report psychosocial problems, whereas males were more likely to report experience of smoking and drinking alcohol and to engage in vigorous physical activity. Stress and unhappiness were significantly associated with suicide attempts in both males and females, and gender differences in these variables were nonsignificant. Depressive symptoms were associated with a higher risk of suicide attempts, and this relationship was significantly stronger for males. The effects of cigarette smoking and risky drinking were significantly stronger in females.

DISCUSSION

Greater exposure to perceived stress, feelings of unhappiness, depression, and higher vulnerability of smoking and heavy drinking accounted for higher suicide attempts of female adolescents. Higher exposure to health-related behaviors and greater vulnerability to depressive symptoms in male were also noted. In conclusion, differences in exposure and vulnerability to psychosocial and behavioral factors may partly explain gender differences in suicide attempts among Korean adolescents.

Cerebral dopamine deficiency, plasma monoamine alterations and neurocognitive deficits in adults with phenylketonuria

BACKGROUND

Phenylketonuria (PKU), a genetic metabolic disorder that is characterized by the inability to convert phenylalanine to tyrosine, leads to severe intellectual disability and other cerebral complications if left untreated. Dietary treatment, initiated soon after birth, prevents most brain-related complications. A leading hypothesis postulates that a shortage of brain monoamines may be associated with neurocognitive deficits that are observable even in early-treated PKU. However, there is a paucity of evidence as yet for this hypothesis.

METHODS

We therefore assessed in vivo striatal dopamine D2/3 receptor (D2/3R) availability and plasma monoamine metabolite levels together with measures of impulsivity and executive functioning in 18 adults with PKU and average intellect (31.2 ± 7.4 years, nine females), most of whom were early and continuously treated. Comparison data from 12 healthy controls that did not differ in gender and age were available.

RESULTS

Mean D2/3R availability was significantly higher (13%; p = 0.032) in the PKU group (n = 15) than in the controls, which may reflect reduced synaptic brain dopamine levels in PKU. The PKU group had lower plasma levels of homovanillic acid (p < 0.001) and 3-methoxy-4-hydroxy-phenylglycol (p < 0.0001), the predominant metabolites of dopamine and norepinephrine, respectively. Self-reported impulsivity levels were significantly higher in the PKU group compared with healthy controls (p = 0.033). Within the PKU group, D2/3R availability showed a positive correlation with both impulsivity (r = 0.72, p = 0.003) and the error rate during a cognitive flexibility task (r = 0.59, p = 0.020).

CONCLUSIONS

These findings provide further support for the hypothesis that executive functioning deficits in treated adult PKU may be associated with cerebral dopamine deficiency.

Impulsivity is associated with blood pressure and waist circumference among adolescents with bipolar disorder

OBJECTIVE

Cardiovascular risk factors (CVRFs) and impulsivity are common in bipolar disorder (BD), and CVRFs are also linked with impulsivity through a number of mechanisms, both behavioral and biological. This study examines the association between CVRFs and impulsivity in adolescents with BD.

METHODS

Subjects were 34 adolescents with BD and 35 healthy control (HC) adolescents. CVRFs were based on International Diabetes Federation metabolic syndrome criteria (triglycerides, high-density lipoprotein cholesterol, waist circumference, blood pressure (BP) and glucose). Impulsivity was measured using the computerized Cambridge Gambling Task (CGT). Analyses controlled for age, IQ, lifetime attention deficit hyperactivity disorder, and current antipsychotic use.

RESULTS

Adolescents with BD had higher diastolic BP (73.36 ± 9.57 mmHg vs. 67.91 ± 8.74 mmHg, U = 401.0, p = 0.03), higher triglycerides (1.13 ± 0.60 mmol/L vs. 0.78 ± 0.38 mmol/L, U = 373.5, p = 0.008), and were more likely to meet high-risk criteria for waist circumference (17.6% vs. 2.9%, p = 0.04) vs. HC. Within the BD group, CGT sub-scores were correlated with CVRFs. For example, overall proportion bet was positively correlated with systolic (r = 0.387, p = 0.026) and diastolic (ρ = 0.404, p = 0.020) BP. Quality of decision-making was negatively correlated with systolic BP (ρ = -0.401, p = 0.021) and waist circumference (ρ = -0.534, p = 0.003). Significant interactions were observed, such that BD diagnosis moderates the relationship between both waist circumference and BP with CGT sub-scores.

CONCLUSION

BP and waist circumference are associated with impulsivity in BD adolescents, but not in HC adolescents. Future studies are warranted to determine temporality and to evaluate whether optimizing CVRFs improves impulsivity among BD adolescents.

Examination of trait impulsivity on the response to a brief mindfulness intervention among college student drinkers

Mindfulness-based strategies show promise for targeting the construct of impulsivity and associated variables among problematic alcohol users. This study examined the moderating role of intervention (mindfulness vs relaxation vs control) on trait impulsivity and three outcomes examined post-intervention (negative affect, positive affect, and urge to drink) among 207 college students with levels of at-risk drinking. Moderation analyses revealed that the relationship between baseline impulsivity and the primary outcomes significantly differed for participants who underwent the mindfulness versus relaxation interventions. Notably, simple slope analyses revealed that negative urgency was positively associated with urge to drink following the mindfulness intervention. Among participants who underwent the relaxation intervention, analysis of simple slopes revealed that negative urgency was negatively associated with urge to drink, while positive urgency was positively associated with positive affect following the relaxation intervention. Findings suggest that level (low vs high) and subscale of impulsivity matter with regard to how a participant will respond to a mindfulness versus relaxation intervention.

Personality differences in early versus late suicide attempters

BACKGROUND

Suicidality is an individual behaviour caused by a complex framework of internal and external factors. The predictive values of personality traits for a suicide attempt have been demonstrated, especially in conjunction with Cloninger's TCI and impulsivity. Two issues remain unsolved, namely whether these traits alter over time after a suicide attempt, and how they may be influenced by depressive symptoms.

METHODS

We studied two patient cohorts: one sample of 81 patients after a suicide attempt no longer than 3 months previously (SA early) and another sample of 32 patients whose attempt had taken place more than 6 months previously (SA late). We carried out structured interviews with these subjects addressing diagnosis (MINI), suicidality (Scale for suicide ideation), depression (HAMD-17), temperament and character inventory (TCI), and impulsivity (BIS-10). Data analysis was done using SPSS 16.0.

RESULTS

Our two groups did not differ significantly in sociodemographics or suicidality. However, patients in the SA early group were significantly more depressed (p < 0.001), and scored lower in reward dependence (p < 0.001) and persistence (p = 0.005) but higher in harm avoidance (p < 0.001); they did not differ significantly in impulsivity (p < 0.01). Reward dependence, persistence, and harm avoidance remained significantly different between the two groups after controlling for depressive symptoms.

CONCLUSIONS

Our findings suggest that some personality traits vary after a suicide attempt. Further investigations are necessary to verify our results, ideally in longitudinal studies with larger, carefully-described cohorts. It would be also clinically important to investigate the influence of therapeutic strategies on the variability of personality traits and their impact on suicidal behavior.

Relationship of impulsivity and depression during early methamphetamine withdrawal in Han Chinese population

OBJECTIVE

High level of impulsivity as well as depression is thought to be involved in the maintenance and development of methamphetamine (METH) addiction. However, the relationship between impulsivity and depression has not been studied thoroughly in METH dependence subjects, especially in early METH abstinent subjects. In this study, our objective is to explore the interplay between the depressive symptoms and impulsivity in early METH abstinent subjects.

METHODS

A total of 182 early abstinent METH dependent subjects (abstinence for 1-7 days) were recruited and the level of impulsivity was measured by the Barratt Impulsiveness Scale (BIS-11). Depressive symptoms and anxiety symptoms were assessed by the short 13-item Beck Depression Inventory (BDI-13) and Beck Anxiety Inventory (BAI) respectively.

RESULTS

Global impulsivity of BIS-11 was significantly correlated with depressive symptoms among early METH abstinent subjects (r=0.283, p=0.001). Moreover, all subscales of BIS-11 were also found to be correlated with depressive symptoms: correlation with attentional impulsivity (r=0.202, p=0.006); correlation with motor impulsivity (r=0.267, p=0.001); and correlation with non-planning impulsivity (r=0.177, p=0.017).

CONCLUSIONS

This study showed a relationship between impulsivity and depression, which may further the comprehension of motivational elements contributing to the maintenance and development of METH use disorder. Future research would be dedicated to exploring underlying mechanisms of association between impulsivity and depression.

Milnacipran remediates impulsive deficits in rats with lesions of the ventromedial prefrontal cortex

BACKGROUND

Deficits in impulse control are often observed in psychiatric disorders in which abnormalities of the prefrontal cortex are observed, including attention-deficit/hyperactivity disorder and bipolar disorder. We recently found that milnacipran, a serotonin/noradrenaline reuptake inhibitor, could suppress impulsive action in normal rats. However, whether milnacipran could suppress elevated impulsive action in rats with lesions of the ventromedial prefrontal cortex, which is functionally comparable with the human prefrontal cortex, remains unknown.

METHODS

Selective lesions of the ventromedial prefrontal cortex were made using quinolinic acid in rats previously trained on a 3-choice serial reaction time task. Sham rats received phosphate buffered saline. Following a period of recovery, milnacipran (0 or 10mg/kg/d × 14 days) was orally administered 60 minutes prior to testing on the 3-choice task. After 7 days of drug cessation, Western blotting, immunohistochemistry, electrophysiological analysis, and morphological analysis were conducted.

RESULTS

Lesions of the ventromedial prefrontal cortex induced impulsive deficits, and repeated milnacipran ameliorated the impulsive deficit both during the dosing period and after the cessation of the drug. Repeated milnacipran remediated the protein levels of mature brain-derived neurotrophic factor and postsynaptic density-95, dendritic spine density, and excitatory currents in the few surviving neurons in the ventromedial prefrontal cortex of ventromedial prefrontal cortex-lesioned rats.

CONCLUSIONS

The findings of this study suggest that milnacipran treatment could be a novel strategy for the treatment of psychiatric disorders that are associated with a lack of impulse control.

Lipid correlates of attentional impulsivity in first episode mania: results from an Indian population

BACKGROUND

Attentional/cognitive impulsivity has been demonstrated as being associated with an increased risk for suicide and other self-harming behaviors, along with a more severe course in patients with bipolar disorder. That an alteration of the various serum lipid fractions might be associated with increased impulsivity has been proposed in the past, but evidences are ambiguous and mainly based on western population data.

OBJECTIVE

The present study was aimed to analyze the attentional impulsivity and various serum lipid fractions in bipolar patients, from an Indian perspective.

MATERIALS AND METHODS

At presentation, 60 drug free/naïve first episode Mania patients were rated on the Barratt impulsiveness scale-version 11 and Young Mania Rating Scale; body mass index (BMI) was calculated and blood samples were analyzed for total cholesterol (TC), high density lipoproteins, low density lipoproteins and very low density lipoproteins (VLDL), triglycerides (TG) and apolipoproteins A1 and B.

RESULTS

The analysis revealed statistically significant negative correlation and inverse linear relationship between TC, TG, VLDL and BMI with attentional impulsivity.

CONCLUSION

The present study adds to the growing literature on a complex relationship between lipid fractions and attentional impulsivity. The findings present interesting insights into the possible substrates of human behavior at biochemical levels. The implications are many, including a need to introspect regarding the promotion of weight loss and cholesterol reduction programs in constitutionally vulnerable population.

Depression and impulsivity as pathways to violence: implications for antiaggressive treatment

BACKGROUND

Difficulties with affect regulation and impulse control have a strong influence on violence. The objective of this study was to determine whether baseline depression and impulsivity predict aggression and whether they predict differential response to antiaggressive treatment. This is important, as we lack knowledge as to the selection of antipsychotics for the treatment of aggression.

METHODS

Physically aggressive inpatients with schizophrenia who received an evaluation of depression and impulsivity at baseline were randomly assigned in a double-blind, parallel group, 12-week trial to clozapine, olanzapine, or haloperidol. Trait impulsivity was measured by the Barratt Impulsiveness Scale; depression by the Positive and Negative Syndrome Scale Depression factor. The number and severity of aggressive events, as measured by the Modified Overt Aggression Scale (MOAS), were the outcome measures.

RESULTS

Baseline depression and impulsivity predicted higher levels of aggression, as measured by the MOAS total score, over the 12-week treatment period across all 3 medication groups. In addition, there was a strong interaction effect between baseline depression/impulsivity and medication grouping in predicting MOAS score. In particular, when higher depression and impulsivity were present at baseline, patients on haloperidol presented with more aggression than patients on the other 3 medications.

CONCLUSIONS

Depression and impulsivity are important predictors of aggression and of differential response to antiaggressive treatment. This is most likely due to the medications' dissimilar neurotransmitter profiles. By identifying patients who will respond better to a given medication, we will be able to develop individualized strategies for the treatment of violent behavior.

Reconsidering the link between impulsivity and suicidal behavior

It is widely accepted that suicidal behavior often occurs with little planning. We propose, however, that suicidal behavior is rarely if ever impulsive-that it is too frightening and physically distressing to engage in without forethought-and that suicidal behavior in impulsive individuals is accounted for by painful and fearsome behaviors capable of enhancing their capacity for suicide. We conducted a meta-analysis of the association between trait impulsivity and suicidal behavior and a critical review of research considering the impulsiveness of specific suicide attempts. Meta-analytic results suggest the relationship between trait impulsivity and suicidal behavior is small. Furthermore, studies examining a mediating role of painful and provocative behaviors have uniformly supported our model. Results from our review suggest that researchers have been unable to adequately measure impulsivity of attempts and that measures sensitive to episodic planning must be developed to further our understanding of this phenomenon.

Impulsivity and risk taking in bipolar disorder and schizophrenia

Impulsive risk taking contributes to deleterious outcomes among clinical populations. Indeed, pathological impulsivity and risk taking are common in patients with serious mental illness, and have severe clinical repercussions including novelty seeking, response disinhibition, aggression, and substance abuse. Thus, the current study seeks to examine self-reported impulsivity (Barratt Impulsivity Scale) and performance-based behavioral risk taking (Balloon Analogue Risk Task) in bipolar disorder and schizophrenia. Participants included 68 individuals with bipolar disorder, 38 with schizophrenia, and 36 healthy controls. Self-reported impulsivity was elevated in the bipolar group compared with schizophrenia patients and healthy controls, who did not differ from each other. On the risk-taking task, schizophrenia patients were significantly more risk averse than the bipolar patients and controls. Aside from the diagnostic group differences, there was a significant effect of antipsychotic (AP) medication within the bipolar group: bipolar patients taking AP medications were more risk averse than those not taking AP medications. This difference in risk taking because of AP medications was not explained by history of psychosis. Similarly, the differences in risk taking between schizophrenia and bipolar disorder were not fully explained by AP effects. Implications for clinical practice and future research are discussed.

The role of neuropeptides in suicidal behavior: a systematic review

There is a growing evidence that neuropeptides may be involved in the pathophysiology of suicidal behavior. A critical review of the literature was conducted to investigate the association between neuropeptides and suicidal behavior. Only articles from peer-reviewed journals were selected for the inclusion in the present review. Twenty-six articles were assessed for eligibility but only 22 studies were included. Most studies have documented an association between suicidality and some neuropeptides such as corticotropin-releasing factor (CRF), VGF, cholecystokinin, substance P, and neuropeptide Y (NPY), which have been demonstrated to act as key neuromodulators of emotional processing. Significant differences in neuropeptides levels have been found in those who have attempted or completed suicide compared with healthy controls or those dying from other causes. Despite cross-sectional associations between neuropeptides levels and suicidal behavior, causality may not be inferred. The implications of the mentioned studies were discussed in this review paper.

Alcohol use, depressive symptoms, and impulsivity as risk factors for suicide proneness among college students

BACKGROUND

Alcohol use, depression, and suicide are significant public health problems, particularly among college students. Impulsivity is associated with all of these factors. Additionally, impulsivity increases the effects of negative mood and alcohol use on maladaptive behavior.

METHODS

The current cross-sectional study examined the association between the four-factor model of impulsivity (urgency, (lack of) perseverance, (lack of) premeditation, and sensation seeking), depressive symptoms, and alcohol use as predictors of suicide proneness among college students. Participants (n=1100) completed online assessments of demographics, impulsivity, depressive symptoms, and suicide proneness.

RESULTS

All predictors were positively related to suicide proneness. The relation between depressive symptoms and suicide proneness was moderated by (lack of) perseverance, alcohol use, and joint interactions of urgency×alcohol use and sensation seeking×alcohol use. Despite some paradoxical findings regarding the depressive symptoms-suicide proneness relation when only one risk factor was elevated, the average level of suicide proneness increased as risk factors increased.

LIMITATIONS

This cross-sectional self-report data comes from a non-clinical sample of college students from a homogeneous background, limiting generalizability and causal predictions.

CONCLUSIONS

Overall, these findings indicate that the association between depressive symptoms and suicide proneness varies considerably by different facets of impulsivity and alcohol use. The results suggest that clinical risk-assessments should weigh two forms of impulsivity (urgency and sensation seeking) as particularly vital in the presence of heavy alcohol use. These findings highlight the importance of considering and exploring moderators of the mood-suicide relationship.

Intelligence, temperament, and personality are related to over- or under-reporting of affective symptoms by patients with euthymic mood disorder

BACKGROUND

Many patients with mood disorders report subjective indicators of depression that are inconsistent with clinicians' objective ratings. This study used the self-report Beck Depressive Inventory (BDI) and the observer-rated Hamilton Depression Rating Scale (HAMD) to evaluate the extent to which temperament, personality traits, and clinical characteristics accounted for discrepancies between self-reports and clinician ratings of depressive symptoms in patients experiencing the euthymic period of a mood disorder.

METHOD

The sample consisted of 100 individuals with bipolar disorder (n=72) or major depressive disorder (n=28). The HAMD and Young Mania Rating Scale were administered, and participants completed the BDI and Barratt Impulsivity Scale. Intelligence was assessed with the Korean Wechsler Adult Intelligence Scale. Patients completed the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire and the NEO-Five-Factor Inventory.

RESULTS

The BDI and HAMD were significantly but modestly correlated with each other (r=0.319, p<0.001). Lower intelligence and a less conscientious personality were independent contributors to differences between Z-scores for the BDI and the HAMD. Higher impulsivity and a more anxious temperament were also observed in the group that self-reported more symptoms than were noted by clinicians.

LIMITATIONS

Generalizability of results can be limited in ethnic difference.

CONCLUSIONS

Subjective and objective assessments of the depressive symptoms of patients with mood disorders in a euthymic mood state are frequently discordant. Clinicians should consider the subjective aspects of depressive symptoms along with objective information about the influence of intelligence and personality on patients' self-reports.

Is impulsivity a common trait in bipolar and unipolar disorders?

OBJECTIVES

  Impulsivity is increased in bipolar and unipolar disorders during episodes and is associated with substance abuse disorders and suicide risk. Impulsivity between episodes predisposes to relapses and poor therapeutic compliance. However, there is little information about impulsivity during euthymia in mood disorders. We sought to investigate trait impulsivity in euthymic bipolar and unipolar disorder patients, comparing them to healthy individuals and unaffected relatives of bipolar disorder patients.

METHODS

  Impulsivity was evaluated by the Barratt Impulsiveness Scale (BIS-11A) in 54 bipolar disorder patients, 25 unipolar disorder patients, 136 healthy volunteers, and 14 unaffected relatives. The BIS-11A mean scores for all four groups were compared through the Games-Howell test for all possible pairwise combinations. Additionally, we compared impulsivity in bipolar and unipolar disorder patients with and without a history of suicide attempt and substance abuse disorder.

RESULTS

  Bipolar and unipolar disorder patients scored significantly higher than the healthy controls and unaffected relatives on all measures of the BIS-11A except for attentional impulsivity. On the attentional impulsivity measures there were no differences among the unaffected relatives and the bipolar and unipolar disorder groups, but all three of these groups scored higher than the healthy participant group. There was no difference in impulsivity between bipolar and unipolar disorder subjects with and without suicide attempt. However, impulsivity was higher among bipolar and unipolar disorder subjects with past substance use disorder compared to patients without such a history.

CONCLUSIONS

  Questionnaire-measured impulsivity appears to be relatively independent of mood state in bipolar and unipolar disorder patients; it remains elevated in euthymia and is higher in individuals with past substance abuse. Elevated attentional and lower non-planning impulsivity in unaffected relatives of bipolar disorder patients distinguished them from healthy participants, suggesting that increased attentional impulsivity may predispose to development of affective disorders, while reduced attentional impulsivity may be protective.

Milnacipran enhances the control of impulsive action by activating D₁-like receptors in the infralimbic cortex

RATIONALE

Elevated impulsivity is often observed in patients with depression. We recently found that milnacipran, an antidepressant and a serotonin/noradrenaline reuptake inhibitor, could enhance impulse control in rats. However, the neural mechanisms underlying the effects of milnacipran on impulsive action remain unclear. Milnacipran increases not only extracellular serotonin and noradrenaline but also dopamine specifically in the medial prefrontal cortex, which is one of the brain regions responsible for impulsive action.

OBJECTIVES

Our goal was to identify whether D(1)- and/or D(2)-like receptors in the infralimbic cortex (IL), the ventral portion of the medial prefrontal cortex, mediates the milnacipran-enhanced impulse control in a three-choice serial reaction time task.

METHODS

The rats were bilaterally injected with SCH23390, a selective D(1)-like receptor antagonist (0.3 or 3 ng/side) or eticlopride, a selective D(2)-like receptor antagonist (0.3 or 1 μg/side) into the IL after acute intraperitoneal administration of milnacipran (10 mg/kg).

RESULTS

Intra-IL SCH23390 injections reversed the milnacipran-enhanced impulse control, whereas injections of eticlopride into the IL failed to block the effects of milnacipran on impulsive action.

CONCLUSIONS

This is the first report that demonstrates a critical role for D(1)-like receptors of the IL in milnacipran-enhanced control of impulsive action.

Genetic variants in the catechol-o-methyltransferase gene are associated with impulsivity and executive function: relevance for major depression

The catechol-o-methyltransferase (COMT) gene has been extensively investigated in depression with somewhat contradictory results but the role of impulsivity, as a possible intermediate phenotype in this disorder, has not been considered yet. In our study, four tagging SNPs in the COMT gene (rs933271, rs740603, rs4680, rs4646316) were genotyped in two independent population cohorts: Manchester (n = 1267) and Budapest (n = 942). First, we investigated the association between COMT genotypes, impulsivity, neuroticism and depression using haplotype trend regression, and constructed a model using structural equation modeling to investigate the interaction between these factors. Secondly, we tested the effect of executive function on this model in a smaller interviewed sample (n = 207). Our results demonstrated that COMT haplotypes were significantly associated with impulsivity in the combined cohort, showing the same direction of effects in both populations. The COMT effect on depressive symptoms (in subjects without history of depression) and on executive function (interviewed sample) showed the opposite pattern to impulsivity. Structural equation models demonstrated that COMT and impulsivity acted, both together (through neuroticism) and independently, to increase the risk of depression. In addition, better executive function also operated as a risk factor for depression, possibly though reduced ability to flexibly disengage negative emotions. In conclusion, variations in the COMT gene exert complex effects on susceptibility to depression involving various intermediate phenotypes, such as impulsivity and executive function. These findings emphasise that modeling of disease pathways at phenotypic level are valuable for identifying genetic risk factors.