[Hallucinogen Persisting Perception Disorder (HPPD) and Flashback Phenomena ­ Differential Diagnosis and Explanation Models]. / Halluzinogen-induzierte Persistierende Wahrnehmungsstörung (HPPD) und Flashback-Phänomene ­ Differenzialdiagnose und Erklärungsmodelle.

OBJECTIVE: The purpose of this article is to provide an overview of the current research on "Hallucinogen Persisting Perception Disorder" (HPPD) and "Flashback" phenomena. The definition and diagnostic features of "Flashback" and HPPD remained often unclear and since the 1960 s interchangeable. METHODS: Relevant literature was identified by means of a computerized MEDLINE search including the years 1994-2014. Finally 75 journal articles out were included in the review. RESULTS: Consistent with the ICD-10 (F16.70) definition "Flashback" is often used to describe brief visual perceptual, mood, and altered states of consciousness effects reminiscent of acute hallucinogen intoxication effects. Many users regard flashback phenomena as benign and even pleasant. HPPD is described in DSM-5 as a visual perceptual disorder, sometimes persisting for months or years causing severe individual distress. The prevalence of flashback and HPPD is unknown. It is considered to be remarkable in view of the relatively few case reports published out of millions of hallucinogen users since the 1960 s and 1970 s. Despite a multitude of etiological and therapeutic approaches the exact pathophysiological mechanisms underlying HPPD remain elusive. At present HPPD appears to be further a DSM-5-genuine but still puzzling disorder. The different consequences including new therapeutic approaches are discussed in clinical context.

[Lie detection and mind reading: is there a use for fMRI?: A critical survey and reflection]. / MRT als Lügendetektor und Gedankenleser?: Kritische Bestandsaufnahme und Reflexion.

Great efforts have been made in recent years to use functional magnetic resonance imaging (fMRI) in the context of lie detection. In the present paper the pros and cons of such an approach are analyzed and critically discussed.Both epistemological and methodical considerations have shown that all attempts to derive mental states from fMRI findings ("reverse inference") are not valid. Consequently, fMRI scans cannot reveal a person's thoughts and whether (s)he is lying or telling the truth.

[Hallucinogen-induced psychological disorders]. / Halluzinogen-induzierte psychische Störungen.

OBJECTIVE: The purpose of this article is to provide an overview of the current research on hallucinogen induced psychiatric disorders. In addition to LSD and psilocybin hallucinogens of biologic origin are increasingly used by adolescents and young adults. METHODS: Relevant literature and related articles were identified by means of a computerized MEDLINE search including the years 1997 - 2007. As keywords "hallucinogen induced psychosis", "hallucinogen induced flashback", "hallucinogen persisting perception disorder (HPPD)" were used. Finally, 64 journal articles and books out of 103 were included in the review. RESULTS: Acute psychotic syndromes in adolescents are rarely due to intoxications with hallucinogenic drugs. However, clinical relevance of flashback phenomena as post-hallucinogenic psychiatric disorder has to be disputed. Because of the high popularity of biogenic hallucinogens and LSD knowledge of intoxications and resulting psychiatric disorders as well as medical complications and therapeutical approaches are clinically important. Especially intoxications with drugs of herbal origin like tropanalcaloids play an important role in emergency situations.

Response inhibition in borderline personality disorder: event-related potentials in a Go/Nogo task.

Borderline personality disorder (BPD) has been related to a dysfunction of anterior cingulate cortex, amygdala, and prefrontal cortex and has been associated clinically with impulsivity, affective instability, and significant interpersonal distress. We examined 17 patients with BPD and 17 age-, sex-, and education matched control participants with no history of Axis I or II psychopathology using event-related potentials (ERPs). Participants performed a hybrid flanker-Go/Nogo task while multichannel EEG was recorded. Our study focused on two ERP components: the Nogo-N2 and the Nogo-P3, which have been discussed in the context of response inhibition and response conflict. ERPs were computed on correct Go trials (button press) and correct Nogo trials (no button press), separately. Groups did not differ with regard to the Nogo-N2. However, BPD patients showed reduced Nogo-P3 amplitudes. For the entire group (n = 34) we found a negative correlation with the Barratt Impulsiveness Scale (BIS-10) and Becks's depression inventory (BDI). The present study is the first to examine Nogo-N2 and Nogo-P3 in BPD and provides further evidence for impaired response inhibition in BPD patients.

[Development of the concept of identity in psychiatry and philosophy]. / Zur Entwicklung des Begriffs der Person in Psychiatrie und Philosophie.

The present paper discusses possible solutions to the problem of personal identity and intends to demonstrate criteria enabling us to view a person as the same at different time points in his life. Of special interest are the so-called memory criterion and the criterion of physical identity/continuity: a person remains the same if he is able to remember his past "states" or if he continues to have his former body (brain). The philosophical discussion of the last decades made clear that all attempts to reduce personal identity to memory or physical continuity are contradictory. In this paper we propose regarding personal identity as a normative phenomenon that evades a purely descriptive or neurobiological approach.

Executive control in obsessive-compulsive disorder: event-related potentials in a Go/Nogo task.

Obsessive-compulsive disorder (OCD) has been related to a hyperactive cortico-striatal-pallidal-thalamic circuitry resulting clinically in an impaired inhibition of repetitive thoughts and behaviors. We examined thirteen patients with OCD and thirteen age-, sex-, and education matched healthy controls using event-related potentials (ERPs). Participants performed a hybrid flanker-Go/Nogo task while multichannel EEG was recorded. Our study focused on two ERP components: the Nogo-N2 and the Nogo-P3, which have been discussed in the context of response inhibition and response conflict. Artifact-free EEG-segments were used to compute ERPs on correct Go trials (button press) and correct Nogo trials (no button press), separately. Patients with OCD showed enhanced (more negative) Nogo-N2 amplitudes than controls, and a significant difference in amplitudes between Nogo-N2 and Go-N2 trials (more negative for Nogo trials) at central midline electrode positions. However, groups did not differ with regard to the Nogo-P3 and Go-P3. The present study replicates and extends previous findings of altered executive control processes in OCD patients.

[Zolpidem dependence and depression in the elderly]. / Zolpidem-Abhängigkeit und Depression im Senium.

In a 75 years-old patient with chronic senile depression criteria of zolpidem dependency were fulfilled. There was no history of benzodiazepine or alcohol abuse. Positive psychotropic effects were emphasized by the patient who spread intake over the day.

Distinct neurophysiological mechanisms for manic and cycloid psychoses: evidence from a P300 study on manic patients.

Pathologically asymmetrical P300 fields with right lateralized peaks were described in core schizophrenia as an expression of left-temporal functional deficits, while higher than normal amplitudes were found in cycloid psychosis. This latter finding appeared to be specific for cycloid psychosis and was explained by a generalized cerebral hyperarousal. Based on some psychopathological analogies with cycloid psychosis, and on the comparable pharmacological treatment of the acute episodes, a group of 19 manic patients was investigated immediately after remission and clinical stabilization of an episode. Patients with psychotic features were excluded to avoid overlaps with cycloid psychosis. Patients showed normal P300 amplitudes and no pathological asymmetries of the field, but more posterior positive areas compared to age- and sex-matched controls. This indicates that the neurophysiological changes underlying mania are different from both core schizophrenia and cycloid psychosis. Based on previous three-dimensional source location studies, this finding indicates that disinhibition due to reduced frontal lobe activity, and not hyperarousal, is the basic functional mechanism of manic disorders.