The role of the CNR1 gene in schizophrenia: a systematic review including unpublished data

Objective: Schizophrenia is a multifactorial disorder. It is known that a combination of extensive multiple common alleles may be involved in its etiology, each contributing with a small to moderate effect, and, possibly, some rare alleles with a much larger effect size. We aimed to perform a systematic review of association studies between schizophrenia (and its subphenotypes) and polymorphisms in the CNR1 gene, which encodes cannabinoid receptors classically implicated in schizophrenia pathophysiology, as well as to present unpublished results of an association study in a Brazilian population. Methods: Two reviewers independently searched for eligible studies and extracted outcome data using a structured form. Papers were retrieved from PubMed and ISI Web of Knowledge using the search term schizophrenia in combination with CNR1 or CB1 or cannabinoid receptor. Twenty-four articles met our inclusion criteria. We additionally present data from a study of our own comparing 182 patients with schizophrenia and 244 healthy controls. Results: No consistent evidence is demonstrated. Conclusion: Some seemingly positive association studies stress the need for further investigations of the possible role of endocannabinoid genetics in schizophrenia

Increased mean platelet volume in patients with panic disorder

Mehmet Hanifi Kokacya,1 Umit Sertan Copoglu,1 Yüksel Kivrak,2 Mustafa Ari,1 Musa Sahpolat,1 Kemal Türker Ulutas3 1Department of Psychiatry, Faculty of Medicine, Mustafa Kemal University, Hatay, 2Department of Psychiatry, Faculty of Medicine, Kafkas University, Kars, 3Department of Biochemistry, Kadirli State Hospital, Osmaniye, Turkey Objective: The relationship between platelet activation and psychiatric disorders has been shown in previous work. Mean platelet volume (MPV) is a measure of platelet size and a good indicator of platelet activity, which increases in cardiovascular diseases (CVDs). It is known that anxiety is a considerable factor in the etiology of mortality in CVDs. The aim of the present study was to investigate any probable difference in the MPV of patients with panic disorder (PD).Methods: Sixty-one drug-free patients, aged 18–65 years and diagnosed with PD according to the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, were included in the study, along with 63 healthy age- and sex-matched volunteers. The body mass index (BMI) was calculated and MPV measured for each subject.Results: The MPV was found to be higher in the PD group compared to the control group (P=0.004). There were no significant differences between the two groups in terms of platelet count or BMI.Conclusion: Alterations in platelet activity may be a reflection of abnormal 5-hydroxytryptamine (5-HT) 1A receptor function in the central nervous system of subjects with a diagnosis of PD. These findings may elucidate the relationship between CVDs and PD. The findings of the present study suggest that MPV is increased in PD patients. Keywords: mean platelet volume, panic disorder, anxiet

High Catalase and Low Thiol Levels in Adult-ADHD Patients

Objective: The prevalence of Adult attention-deficit/hyperactivity disorder (A-ADHD) has been estimated as to be around 5%. There are several hypotheses regarding the etiology of ADHD. Although numerous researches have been conducted regarding neurobiology of pediatric ADHD, A-ADHD studies were relatively few. Many studies have indicated that oxidant mediated neuronal damage may play a role in the pathophysiology of various psychiatric disorders. Recently, oxidative stress has been studied in A-ADHD and there is an accumulating evidence to support its' role. In the present study, we aimed to evaluate catalase (CAT) and thiol levels in A-ADHD patients and compare with healthy controls. Materials-Methods: Twenty-five A-ADHD patients from Gaziantep University, diagnosed according to Turgay's Turkish version of Adult ADD/ADHD DSM IV-Based Diagnostic Screening and Rating Scale by two psychiatrists, and 25 healthy volunteer controls were included. The subjects strictly refrained from any substance intake and physical exercise after 08:00 p.m. on the day before collection. CAT and Thiol levels were measured in plasma samples of study groups. Results: Age, gender, and body mass indexes of patients and controls have shown homogeneity and there were no differences between the groups. Total score and subscores were not correlated with any of the mentioned biochemical parameters. The mean CAT levels in patients with ADHD were significantly higher and Thiol levels were lower than those of controls (<0.001, <0.001, respectively). When the comorbid patient group compared with pure A-ADHD patients in terms of CAT (11.49 +/- 0.28, 11.51 +/- 0.40, respectively) and thiol (0.22 +/- 0.05, 0.25 +/- 0.03, respectively) levels there were not found any significant differences (p=0.865, p=0.174, respectively). Conclusions: The results of the present study may indicate that thiol levels may be decreased with in reaction of increased CAT levels and thiol act like a pro-oxidant. This study may be considered as one of the initial phase studies that lighten the relationship between oxidative stress and A-ADHD.There is a need for further studies that will prove this relationship exactly