Cannabidiol enhances anandamide signaling and alleviates psychotic symptoms of schizophrenia.

Cannabidiol is a component of marijuana that does not activate cannabinoid receptors, but moderately inhibits the degradation of the endocannabinoid anandamide. We previously reported that an elevation of anandamide levels in cerebrospinal fluid inversely correlated to psychotic symptoms. Furthermore, enhanced anandamide signaling let to a lower transition rate from initial prodromal states into frank psychosis as well as postponed transition. In our translational approach, we performed a double-blind, randomized clinical trial of cannabidiol vs amisulpride, a potent antipsychotic, in acute schizophrenia to evaluate the clinical relevance of our initial findings. Either treatment was safe and led to significant clinical improvement, but cannabidiol displayed a markedly superior side-effect profile. Moreover, cannabidiol treatment was accompanied by a significant increase in serum anandamide levels, which was significantly associated with clinical improvement. The results suggest that inhibition of anandamide deactivation may contribute to the antipsychotic effects of cannabidiol potentially representing a completely new mechanism in the treatment of schizophrenia.

Independent protein-profiling studies show a decrease in apolipoprotein A1 levels in schizophrenia CSF, brain and peripheral tissues.

Although some insights into the etiology of schizophrenia have been gained, an understanding of the illness at the molecular level remains elusive. Recent advances in proteomic profiling offer great promise for the discovery of markers underlying pathophysiology of diseases. In the present study, we employed two high-throughput proteomic techniques together with traditional methods to investigate cerebrospinal fluid (CSF), brain and peripheral tissues (liver, red blood cells and serum) of schizophrenia patients in an attempt to identify peripheral/surrogate disease markers. The cohorts used to investigate each tissue were largely independent, although some CSF and serum samples were collected from the same patient. To address the major confounding factor of antipsychotic drug treatment, we also included a large cohort of first-onset drug-naive patients. Apolipoprotein A1 (apoA1) showed a significant decrease in expression in schizophrenia patients compared to controls in all five tissues examined. Specifically, using SELDI-TOF mass spectrometry, apoA1 was found decreased in CSF from schizophrenia patients (-35%, P=0.00001) and, using 2D-DIGE, apoA1 was also found downregulated in liver (-30%, P=0.02) and RBCs (-60%, P=0.003). Furthermore, we found a significant reduction of apoA1 in sera of first-onset drug-naive schizophrenia patients using enzyme-linked immunosorbent assay (-18%, P=0.00008) and in two investigations of post-mortem brain tissue using western blot analysis (-35%, P=0.05; -51%, P=0.05). These results show that apoA1 is consistently downregulated in the central nervous system as well as peripheral tissues of schizophrenia patients and may be linked to the underlying disease mechanism.

[Efficacy and tolerability of quetiapine in hospitalised schizophrenic patients during the acute treatment phase: a PMS study]. / Wirksamkeit und Verträglichkeit von Quetiapin in der stationären Akutbehandlung schizophrener Psychosen: Eine Anwendungsbeobachtung.

We performed a post marketing surveillance study (PMS study) to reveal the efficacy and tolerability of orally administered quetiapine in the treatment of acute psychosis over a period of up to three weeks. 398 respective inpatients were assessed in 88 psychiatric departments in Germany by use of the Clinical Global Impression Scale (CGI) and the Brief Psychiatric Rating Scale (BPRS) as well as the clinical impression of psychiatric raters. Safety and tolerability were assessed by vital parameters such as blood pressure, hearth rate and weight as well as the clinical impression of the psychiatric raters. In addition, dosing, concomitant and/or previous pharmacotherapies as well as certain aspects of psychiatric and medical history were documented. A significant reduction of psychopathology was found during three weeks of drug treatment. Daily dosages of quetiapine between 400 and 1200 mg were well tolerated with a limited number of adverse and no serious adverse events. Noteworthy, more than 35 % of all patients received and tolerated excellently more than 800 mg of quetiapine per day under naturalistic treatment conditions, well above the approved maximum daily dosage. This study reflects the clinical efficacy and good tolerability of quetiapine under real world treatment conditions and is in line with the results of the controlled clinical trials of phase II and III.