Abreaction for conversion disorder: systematic review with meta-analysis.

BACKGROUND: The value of drug interviews in the treatment of conversion disorder is at present unknown. AIMS: To review all the available papers published in English that report on the use of drug interviews for treating conversion/dissociative disorder. METHOD: Databases (including EMBASE, MEDLINE and PsycINFO) were searched from 1920 to 2009. Selected publications had to report on the use of drug interviews in people diagnosed with a conversion/dissociative disorder. Qualitative and quantitative data were extracted. Predictors of a positive response were ascertained using meta-analytic techniques. RESULTS: Fifty-five papers meeting inclusion criteria were identified. No studies compared the intervention with a suitable control group. However, two studies reported high response rates when drug interview was used in individuals with treatment-resistant conversion disorder. In the meta-analysis, the use of suggestion and occurrence of emotional catharsis during the interview were positively associated with recovery. Combining two medications and comorbid psychiatric disorder were negatively associated with recovery. CONCLUSIONS: The evidence for effectiveness of drug interviews is of poor quality but it may be of benefit in the treatment of acute and treatment-resistant conversion disorder. A proactive approach during the interview, making suggestions the individual will respond, could influence outcome. Comorbid psychiatric disorder should be treated conventionally. Experimental studies to determine efficacy are required.

Heterogeneity and specificity of presynaptic Ca2+ current modulation by mGluRs at individual hippocampal synapses.

GABA release from axonal boutons formed by cortical interneurons shows target cell-dependent sensitivity to group III metabotropic glutamate receptor (mGluR) agonists, as well as variable dependence on presynaptic Ca2+ influx via N- and P-type channels. How Ca2+ channels interact with heterogeneous mGluR modulation to determine information flow in the synaptic circuitry is not known. Here we combine electrophysiology with two-photon microscopy to analyze Ca2+ influx at individual axonal varicosities of hippocampal interneurons. Action potentials triggered Ca2+ influx at individual varicosities, principally (>80%) via N- and P-type channels. Although Ca2+ influx at some varicosities was almost entirely mediated by N-type channels, P-type channels only contributed up to 60% of the action potential-evoked Ca2+ transient. At a subset of synapses activation of group III mGluRs depressed GABA release, and decreased Ca2+ influx via N-type channels (in contrast to an action on P-type channels reported at auditory brainstem calyceal synapses). The identity of the dominant channel subtype mediating Ca2+ influx tended to be conserved at varicosities supplied by the same axon. In contrast, neighboring varicosities often showed heterogeneous sensitivity to group III mGluR activation. Glutamatergic modulation of GABA release from individual synapses thus depends on the co-occurrence of presynaptic N-type Ca2+ channels and the target cell-dependent expression of group III mGluRs.