Temperament and character in psychotic depression compared with other subcategories of depression and normal controls

A network view on psychiatric disorders: network clusters of symptoms as elementary syndromes of psychopathology

Introduction

The vast number of psychopathological syndromes that can be observed in clinical practice can be described in terms of a limited number of elementary syndromes that are differentially expressed. Previous attempts to identify elementary syndromes have shown limitations that have slowed progress in the taxonomy of psychiatric disorders.

Aim

To examine the ability of network community detection (NCD) to identify elementary syndromes of psychopathology and move beyond the limitations of current classification methods in psychiatry.

Methods

192 patients with unselected mental disorders were tested on the Comprehensive Psychopathological Rating Scale (CPRS). Principal component analysis (PCA) was performed on the bootstrapped correlation matrix of symptom scores to extract the principal component structure (PCS). An undirected and weighted network graph was constructed from the same matrix. Network community structure (NCS) was optimized using a previously published technique.

Results

In the optimal network structure, network clusters showed a 89% match with principal components of psychopathology. Some 6 network clusters were found, including "DEPRESSION", "MANIA", “ANXIETY”, "PSYCHOSIS", "RETARDATION", and "BEHAVIORAL DISORGANIZATION". Network metrics were used to quantify the continuities between the elementary syndromes.

Conclusion

We present the first comprehensive network graph of psychopathology that is free from the biases of previous classifications: a ‘Psychopathology Web’. Clusters within this network represent elementary syndromes that are connected via a limited number of bridge symptoms. Many problems of previous classifications can be overcome by using a network approach to psychopathology.

The relationship between temperament and character and subclinical psychotic-like experiences in healthy adults

BACKGROUND

Considerable data support phenomenological and temporal continuity between psychotic disorders and subclinical psychotic-like experiences (PLE's). Although numerous studies have found similar personality correlates for schizophrenia and schizotypal personality disorder patients, their unaffected first-degree relatives, and healthy adults characterized for schizotypal traits, no study has yet investigated personality correlates of PLE's measured by the Community Assessment of Psychic Experiences (CAPE). Our study sought to examine personality correlates of PLE's using the CAPE in healthy adults.

METHOD

The CAPE and temperament and character inventory (TCI) were administered to 415 healthy adults. Regressions examined links between TCI traits and overall PLE levels as well as positive and negative PLE's separately.

RESULTS

Consistent with past studies, lower self-directedness (SD) and reward dependence (RD) and higher self-transcendence (ST) and harm avoidance (HA) significantly predicted overall PLE levels. Higher ST and persistence (P) and lower SD significantly predicted higher levels of positive PLE's while lower SD and RD and higher HA, ST, and cooperativeness (C) predicted higher levels of negative PLE's.

CONCLUSIONS

Associations between TCI and PLE's using the CAPE are strikingly similar to past work in non-clinical and patient samples and provide additional support for phenomenological continuity between psychotic disorders and sub-syndromal psychotic symptoms.

Increased plasma norepinephrine concentration in psychotic depression

OBJECTIVE

We previously found psychotic depression (PSDEP) to have positively correlating plasma norepinephrine (NE) and vasopressin (AVP) concentrations. Since central noradrenergic activity and plasma NE concentration are highly correlated, this suggests an increased noradrenergic activation of the hypothalamus-pituitary-adrenal axis. We hypothesize the increased release of NE in PSDEP to be an associated mechanism.

METHODS

To test this hypothesis we analyzed the relation between plasma NE and PSDEP in a comparison with non-psychotically depressed patients. Potentially confounding variables were, among others, melancholia and two better validated subcategories in the field of melancholia and endogenous depression, three global dimensions of psychopathology - Emotional Dysregulation, Retardation and Anxiety - smoking habit, and different types of psychotropic and particularly antidepressant treatment. The data from nine patients with PSDEP and 69 patients with non-PSDEP were reanalysed.

RESULTS

Analysis of covariance controlling for the effects of tricyclic antidepressant treatment (≥100 mg) and smoking habit showed that PSDEP had an increased concentration of plasma NE. The previously found correlation between plasma NE and AVP was still present after correcting for the effects of confounding variables.

CONCLUSIONS

The results suggest an increased activity of the sympathetic nervous system in PSDEP that may act as a specific mechanism for increased vasopressinergic activation. This supports the view of PSDEP as a distinct subcategory of major depression.