Research interest concerning associations between sleep characteristics and suicidality in psychopathology has been growing. However, possible linkages of suicidality to sleep characteristics in terms of sleep quality and chronotypes among depressive patients have not been well documented. In the current study, the authors investigated the possible effects of sleep quality and chronotype on the severity of depressive symptoms and suicide risk in patients with depressive disorder and healthy controls. The study was conducted on 80 patients clinically diagnosed with major depression and 80 healthy subjects who were demographically matched with the patient group. All participants completed a questionnaire package containing self-report measures, including the Beck Depression Inventory (BDI), Pittsburgh Sleep Quality Index (PSQI), Morningness-Eveningness Questionnaire (MEQ), and Suicide Ideation Scale (SIS), and subjects were interviewed with the suicidality section of the Mini-International Neuropsychiatric Interview (MINI). Results are as follows: (a) logistic regression analyses revealed that poor sleep quality and depression symptom severity significantly predicted onset of major depression; (b) morningness-type circadian rhythm may play as a significant relief factor after onset of major depression; (c) sleep variables of chronotype and sleep quality did not significantly predict suicide ideation after controlling for depressive symptoms in the major depression group; and (d) suicide ideation and poor sleep quality were antecedents of depression symptom severity in patients with major depression, and in healthy controls. Findings are discussed under the theoretical assumptions concerning possible relations between chronotype, sleep quality, depression, and suicidality.

Studies attempting to clarify the relationship between major depressive disorder (MDD) and the immune system have been increasing in recent years. It was reported that increased production of the main proinflammatory cytokines, such as interleukin-1, interleukin-6, and tumor necrosis factor-alpha, and that of acute phase reactants may play a role in the etiopathogenesis of depression. Stress and depression were reported to increase leukocyte and neutrophil counts and to decrease lymphocyte count. Biological determinants affecting the diagnosis, therapy, and prognosis of depression are quite limited. Therefore, new etiological models are needed to explain the pathophysiology of depression. In recent years, neutrophil–lymphocyte ratio (NLR) was determined to be a good indicator of inflammatory status. There is no study in the literature investigating NLR in MDD. This study aims to examine the role of inflammation in the etiology of depression based on the NLR in MDD patients who are undergoing no pharmacological therapy. A total of 41 patients diagnosed with MDD, who received no antidepressant therapy within the past 1 month, were included in the study, which took place between January and March 2015. The control group consisted of 47 healthy subjects with no psychiatric disorders. A sociodemographic information form and a Beck Depression Scale were administered, and the blood was taken for biochemical analysis. Significant differences were identified in the NLR, neutrophil count, lymphocyte percentage, and leukocyte values of the patient group when compared with the control group (P<0.05). Our study is the first in which NLR was investigated in MDD. The findings of the study reveal that NLR tends to be higher in patients with MDD, and a high NLR value supports the view that inflammation is a critical factor in the etiology of MDD.

The present findings suggest that risperidone may be more effective than aripiprazole.

Morning- and evening-type individuals differ on a number of psychological and biological variables. There has been increasing interest in the relationship between chronotype and personality traits. The aim of this study was to investigate the relationship between impulsivity and chronotype in suicide attempters. Eighty-nine suicide attempters were included in the study, and systematic information on suicide attempts was recorded. The Morningness-Eveningness Questionnaire was applied to determine chronotype, and attempter impulsivity was measured by the total score of the Barratt Impulsiveness Scale. Significant differences between chronotype and impulsivity scores were found. Evening-type subjects reported significantly higher impulsivity scores than both neither- and morning-types. A significant association between chronotype and type of suicide attempt was detected. The largest proportion of violent suicide attempters were evening-type subjects. Violent suicide attempters also reported significantly higher impulsivity scores than nonviolent attempters. Previous studies have pointed out possible relations between eveningness and impulsivity. Current findings suggest that eveningness may be a risk factor for violent suicide attempts by increasing impulsivity.

ObjectiveHuman serum paraoxonase (PON1) prevents lipids from peroxidation and functions as an antioxidant mechanism. Malonyldialdehyde (MDA) is the final product of lipid peroxidation and can be used as an indicator of oxidative stress. The aim of this study was to investigate PON1, MDA, and arylesterase (ARY) levels in schizophrenic patients who are taking typical, atypical, or combined (typical and atypical) antipsychotic drug treatment, with respect to those of healthy controls.MethodsWe evaluated 41 patients (11 taking typical antipsychotics, 19 taking atypical antipsychotics, 11 taking combined anti-psychotics) and 43 healthy controls.ResultsMDA levels were higher in schizophrenic patients taking typical antipsychotics compared with healthy controls (p=0.001). ARY levels were higher in patients taking atypical antipsychotics compared with healthy controls (p=0.005). PON1 activity was similar in all groups.ConclusionOur results indicate that treatment with typical antipsychotic drugs could be related to increased MDA levels; and antipsychotic medication may increase PON1 levels in schizophrenic patients.