Psychopathological and demographic characteristics of hallucinating patients with schizophrenia and schizoaffective disorder: an analysis based on AMDP data

Pavlovian conditioning-induced hallucinations reduce MMN amplitudes for duration but not frequency deviants

The mismatch negativity (MMN) is an evoked potential that indexes auditory regularity violations. Since the 90's, a reduced amplitude of this brain activity in patients with schizophrenia has been consistently reported. Recently, this alteration has been related to the presence of auditory hallucinations (AHs) rather than the schizophrenia diagnostic per se. However, making this attribution is rather problematic due to the high heterogeneity of symptoms in schizophrenia. In an attempt to isolate the AHs influence on the MMN amplitude from other cofounding variables, we artificially induced AHs in a non-clinical population by Pavlovian conditioning. Before and after conditioning, volunteers (N = 31) participated in an oddball paradigm that elicited an MMN. Two different types of deviants were presented: a frequency and a duration deviant, as the MMN alteration seems to be especially present in schizophrenia with the latter type of deviant. Hence, this pre-post design allowed us to compare whether experiencing conditioning-induced AHs exert any influence on MMN amplitudes. Our results show that duration-deviant related MMN reductions significantly correlate with the number of AHs experienced. Moreover, we found a significant correlation between AHs proneness (measured with the Launay-Slade Hallucination Extended Scale) and the number of AHs experienced during the paradigm. In sum, our study shows that AHs can be conditioned and exert similar effects on MMN modulation in healthy participants as has been reported for patients with schizophrenia. Thus, conditioning paradigms offer the possibility to study the association between hallucinations and MMN reductions without the confounding variables present in schizophrenia patients.

Visual hallucinations in psychiatric, neurologic, and ophthalmologic disease

PURPOSE OF REVIEW

Recent studies have increased our understanding of the biochemical and structural bases of visual hallucinations in patients with a variety of underlying causes.

RECENT FINDINGS

Visual hallucinations may be related to disruption of functional connectivity networks, with underlying biochemical dysfunction such as decreased in cholinergic activity. Structural abnormalities in primary and higher order visual processing areas also have been found in patients with visual hallucinations. The occurrence of visual hallucinations after vision loss, the Charles Bonnet syndrome, may have more functional similarity to psychiatric and neurodegenerative causes than previously suspected despite retained insight into the unreal nature of the phenomena.

SUMMARY

Visual hallucinations are common, and patients may not report them if specific inquiries are not made. Presence or absence of hallucinations may be of diagnostic and therapeutic importance, especially in patients with neurodegenerative conditions that have overlapping features. Treatment of visual hallucinations remains challenging and must be tailored to each patient based on the underlying cause and comorbid conditions.

A typical antipsychotic treatment induced gradually expanding white matter alterations in healthy individuals with persistent auditory verbal hallucinations-an artificially controlled pilot study

OBJECTIVE

The aim of this study was to explore the effects of atypical antipsychotics (AaPs) on brain white matter (WM) tracts in healthy individuals with auditory verbal hallucinations (Hi-AVHs).

METHODS

We analyzed neuroimaging, AVH symptoms, and cognitive assessment data obtained from 39 Hi-AVHs who reported being distressed by persistent AVHs and volunteered to receive AaP treatment. We used tract-based spatial statistics (TBSS) and t tests to explore AaP pharmacotherapy effects on AVH symptoms and brain WM alterations in Hi-AVH subjects.

RESULTS

TBSS and t tests revealed WM alterations after AaP treatment, relative to pretreatment observations. Although AaPs alleviated AVH symptoms, WM alterations in these subjects expanded over 8 months of AaP treatment, encompassing most major WM tracts by the end of the observation period, including the corpus callosum, arcuate fasciculus, cortico-spinal tracts, anterior commissure, and posterior commissure.

CONCLUSIONS

The worsening of AaP-associated WM alterations observed in this study suggest that AaPs may not be a good choice for the treatment of Hi-AVHs despite their ability to alleviate AVHs.

Test-retest reliability of the diagnosis of schizoaffective disorder in childhood and adolescence - A systematic review and meta-analysis

OBJECTIVES

Reliability of schizoaffective disorder (SAD) diagnoses is low in adults but unclear in children and adolescents (CAD). We estimate the test-retest reliability of SAD and its key differential diagnoses (schizophrenia, bipolar disorder, and unipolar depression).

METHODS

Systematic literature search of Medline, Embase, and PsycInfo for studies on test-retest reliability of SAD, in CAD. Cohen's kappa was extracted from studies. We performed meta-analysis for kappa, including subgroup and sensitivity analysis (PROSPERO protocol: CRD42013006713).

RESULTS

Out of > 4000 records screened, seven studies were included. We estimated kappa values of 0.27 [95%-CI: 0.07 0.47] for SAD, 0.56 [0.29; 0.83] for schizophrenia, 0.64 [0.55; 0.74] for bipolar disorder, and 0.66 [0.52; 0.81] for unipolar depression. In 5/7 studies kappa of SAD was lower than that of schizophrenia; similar trends emerged for bipolar disorder (4/5) and unipolar depression (2/3). Estimates of positive agreement of SAD diagnoses supported these results.

LIMITATIONS

The number of studies and patients included is low.

CONCLUSIONS

The point-estimate of the test-retest reliability of schizoaffective disorder is only fair, and lower than that of its main differential diagnoses. All kappa values under study were lower in children and adolescents samples than those reported for adults. Clinically, schizoaffective disorder should be diagnosed in strict adherence to the operationalized criteria and ought to be re-evaluated regularly. Should larger studies confirm the insufficient reliability of schizoaffective disorder in children and adolescents, the clinical value of the diagnosis is highly doubtful.