The DSM-5 Personality and Personality Disorders Work Group formulated a hybrid dimensional/categorical model that represented personality disorders as combinations of core impairments in personality functioning with specific configurations of problematic personality traits. Specific clusters of traits were selected to serve as indicators for six DSM categorical diagnoses to be retained in this system – antisocial, avoidant, borderline, narcissistic, obsessive–compulsive and schizotypal personality disorders. The goal of the current study was to describe the empirical relationships between the DSM-5 section III pathological traits and DSM-IV/DSM-5 section II personality disorder diagnoses.

Data were obtained from a sample of 337 clinicians, each of whom rated one of his or her patients on all aspects of the DSM-IV and DSM-5 proposed alternative model. Regression models were constructed to examine trait–disorder relationships, and the incremental validity of core personality dysfunctions (i.e. criterion A features for each disorder) was examined in combination with the specified trait clusters.

Findings suggested that the trait assignments specified by the Work Group tended to be substantially associated with corresponding DSM-IV concepts, and the criterion A features provided additional diagnostic information in all but one instance.

Although the DSM-5 section III alternative model provided a substantially different taxonomic structure for personality disorders, the associations between this new approach and the traditional personality disorder concepts in DSM-5 section II make it possible to render traditional personality disorder concepts using alternative model traits in combination with core impairments in personality functioning.

Several lines of evidence suggest that bipolar disorder (BD) is associated with white matter (WM) pathology. Investigation of unaffected first-degree relatives of BD patients may help to distinguish structural biomarkers of genetic risk without the confounding effects of burden of illness, medication or clinical state. In the present study, we applied tract-based spatial statistics to study WM changes in patients with BD, unaffected siblings and controls.

A total of 27 euthymic patients with BD type I, 20 unaffected siblings of bipolar patients and 29 healthy controls who did not have any current or past diagnosis of Axis I psychiatric disorders were enrolled in the study.

Fractional anisotropy (FA) was significantly lower in BD patients than in the control group in the corpus callosum, fornix, bilateral superior longitudinal fasciculus, inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, anterior thalamic radiation, posterior thalamic radiation, cingulum, uncinate fasciculus, superior corona radiata, anterior corona radiata and left external capsule. In region-of-interest (ROI) analyses, we found that both unaffected siblings and bipolar patients had significantly reduced FA in the left posterior thalamic radiation, the left sagittal stratum, and the fornix compared with healthy controls. Average FA for unaffected siblings was intermediate between the healthy controls and bipolar patients within these ROIs.

Decreased FA in the fornix, left posterior thalamic radiation and left sagittal stratum in both bipolar patients and unaffected siblings may represent a potential structural endophenotype or a trait-based marker for BD.

Studies on whether the co-occurrence of psychotic experiences (PEs) and depression confers a more pronounced decrement in health status and function compared with depression alone are scarce in the general adult population.

Data on 195 479 adults aged ⩾18 years from the World Health Survey were analysed. Using the World Mental Health Survey version of the Composite International Diagnostic Interview (CIDI), depression in the past 12 months was categorized into four groups: depressive episode, brief depressive episode, subsyndromal depression, and no depression. Past 12-month psychotic symptoms were assessed using four questions on positive symptoms from the CIDI. Health status across seven domains (cognition, interpersonal activities, sleep/energy, self-care, mobility, pain/discomfort, vision) and interviewer-rated presence of a mental health problem were assessed. Multivariable logistic and linear regression analyses were performed to assess the associations.

When compared with those with no depression, individuals with depression had higher odds of reporting at least one PE, and this was seen across all levels of depression severity: subsyndromal depression [odds ratio (OR) 2.38, 95% confidence interval (CI) 2.02–2.81], brief depressive episode (OR 3.84, 95% CI 3.31–4.46) and depressive episode (OR 3.75, 95% CI 3.24–4.33). Having coexisting PEs and depression was associated with a higher risk for observable illness behavior and a significant decline in health status in the cognition, interpersonal activities and sleep/energy domains, compared with those with depression alone.

This coexistence of depression and PEs is associated with more severe social, cognitive and sleep disturbances, and more outwardly apparent illness behavior. Detecting this co-occurrence may be important for treatment planning.

Research suggests that personality traits have both direct and indirect effects on the development of psychological symptoms, with indirect effects mediated by stressful or traumatic events. This study models the direct influence of personality traits on residualized changes in internalizing and externalizing symptoms following a stressful and potentially traumatic deployment, as well as the indirect influence of personality on symptom levels mediated by combat exposure.

We utilized structural equation modeling with a longitudinal prospective study of 522 US National Guard soldiers deployed to Iraq. Analyses were based on self-report measures of personality, combat exposure, and internalizing and externalizing symptoms.

Both pre-deployment Disconstraint and externalizing symptoms predicted combat exposure, which in turn predicted internalizing and externalizing symptoms. There was a significant indirect effect for pre-deployment externalizing symptoms on post-deployment externalizing via combat exposure (p < 0.01). Negative Emotionality and pre-deployment internalizing symptoms directly predicted post-deployment internalizing symptoms, but both were unrelated to combat exposure. No direct effects of personality on residualized changes in externalizing symptoms were found.

Baseline symptom dimensions had significant direct and indirect effects on post-deployment symptoms. Controlling for both pre-exposure personality and symptoms, combat experiences remained positively related to both internalizing and externalizing symptoms. Implications for diagnostic classification are discussed.

Traditional approaches for the classification of eating disorders (EDs) attribute symptoms to an underlying, latent disease entity. The network approach is an alternative model in which mental disorders are represented as networks of interacting, self-reinforcing symptoms. This project was the first to use network analysis to identify interconnected systems of ED symptoms.

Adult participants (n = 143; 77.6% women) with a Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-5) ED were recruited from the community to take part in a larger ongoing longitudinal study. The Structured Clinical Interview for DSM Disorders (SCID-I) was used to establish diagnoses. An undirected network of ED symptoms was created using items from the Eating Pathology Symptoms Inventory (EPSI) and the R package qgraph.

Body checking emerged as the strongest and most important single symptom in the entire network by having the shortest average distance to other symptoms in the network, and by being the most frequent symptom on the path between any two other symptoms. Feeling the need to exercise every day and two symptoms assessing dietary restraint/restricting emerged as ‘key players’, such that their removal from the network resulted in maximal fracturing of the network into smaller components.

Although cognitive–behavioral therapy for EDs focuses on reducing body checking to promote recovery, our data indicate that amplified efforts to address body checking may produce stronger (and more enduring) effects. Finally, results of the ‘key players analysis’ suggested that targeting interventions at these key nodes might prevent or slow the cascade of symptoms through the ‘network’ of ED psychopathology.

Depression and anxiety in Parkinson's disease are common and frequently co-morbid, with significant impact on health outcome. Nevertheless, management is complex and often suboptimal. The existence of clinical subtypes would support stratified approaches in both research and treatment.

Five hundred and thirteen patients with Parkinson's disease were assessed annually for up to 4 years. Latent transition analysis (LTA) was used to identify classes that may conform to clinically meaningful subgroups, transitions between those classes over time, and baseline clinical and demographic features that predict common trajectories.

In total, 64.1% of the sample remained in the study at year 4. LTA identified four classes, a ‘Psychologically healthy’ class (approximately 50%), and three classes associated with psychological distress: one with moderate anxiety alone (approximately 20%), and two with moderate levels of depression plus moderate or severe anxiety. Class membership tended to be stable across years, with only about 15% of individuals transitioning between the healthy class and one of the distress classes. Stable distress was predicted by higher baseline depression and psychiatric history and younger age of onset of Parkinson's disease. Those with younger age of onset were also more likely to become distressed over the course of the study.

Psychopathology was characterized by relatively stable anxiety or anxious-depression over the 4-year period. Anxiety, with or without depression, appears to be the prominent psychopathological phenotype in Parkinson's disease suggesting a pressing need to understanding its mechanisms and improve management.