Review of Standard Laboratory Blood Parameters in Patients with Schizophrenia and Bipolar Disorder

Abstract

Introduction: Symptomatic and etiopathologic heterogeneity of schizophrenia (SCH) and bipolar disorder (BD) can be adequately addressed using a dimensional approach to psychopathology, as well as interpreting physiological properties and markers as predictors of disease onset and relapse. Risk factors, genetic and environmental, are likely to modify the neurobiological processes characteristic of certain physiological processes that manifest to a greater degree of overlapping symptoms. One of the most common laboratory tests in psychiatric patients is a standard laboratory blood test. It gives us an insight into the general somatic condition of the patient. It assesses the ability to transport oxygen to tissues and carbon dioxide back to the lungs via erythrocytes (RBC) and hemoglobin (HGB) as their most important constituents, and is also an indicator of iron status and blood oxygenation.

Aim: Schizophrenia (SCH) and bipolar disorder (BD) are psychiatric disorders whose complex etiology and pathogenesis are still far from known. A correlation between red blood cell abnormalities and these diseases has been recognized in some studies. One of the most common laboratory tests in psychiatric patients is a standard laboratory blood test. However, so far there is a small number of published papers that relate to the relationship between laboratory parameters of blood and the aim of this paper is to reveal more light in this subject.

Methods: The research was done as an observational prospective clinical study that has evaluated different physiological and pathological parameters in patients with BD and SCH over a two-year period. A total of 159 patients with schizophrenia, 61 patients diagnosed with bipolar disorder and 82 healthy subjects participated in this study.

Results: At baseline, BD compared to SCH patients had higher mean lymphocyte count (2,6±0,7 vs. 2,0±0,6x10⁹; p=0,006) and haemoglobin concentration (146,8±12,2 vs. 140,2±14,7 g/L; p=0,03), and significantly lower red cell distribution width (13,6±2,2 vs. 14,7±1,8%; p=0,008). In both BD and SCH patients there was a significant number of patients with low red blood cells count and low haemoglobin concentration, and high MCH and MCHC at baseline and at 3 and 6 months of follow up.

Conclusions: The finding that SCH as well as BD differed from controls with respect to red blood cells, hemoglobin, lymphocytes, and average platelet count was consistent with previous findings and could be understood as a qualitative measure in the evaluation of this sample. The fact that no association with other parameters was found, as well as an association with the diagnosis, does not exclude that these associations can be found in larger samples.

Keywords: Bipolar disorder; Blood cells; Schizophrenia.