Iranian Journal of Psychiatry 2017. 12(1):1-7.

Cortical Alpha Activity in Schizoaffective Patients
Mahdi Moeini, Ali Khaleghi, Mohammad Reza Mohammadi, Hadi Zarafshan, Rachel L. Fazio, Hamid Majidi


Objective: Electrophysiological studies have identified abnormal oscillatory activities in the cerebral cortex in schizophrenia and mood disorders. Biological and pathophysiological evidence suggests specific deficits in serotonin (5-HT) receptor function in schizoaffective disorder (SA), a clinical syndrome with characteristics of both schizophrenia and bipolar disorder. This study investigated alpha oscillations in patients with SA.

Method: Electroencephalography was used to measure ongoing and evoked alpha oscillations in 38 adults meeting Diagnostic and Statistical Manual of Mental Disorders–Fourth Edition (DSM–IV) criteria for SA, and in 39 healthy controls.

Results: Spontaneous alpha power of the participants with SA was significantly lower than that of healthy participants [F (1, 75) = 8.81, P < 0.01]. Evoked alpha activity was also decreased in SA compared to controls [F (1, 75) = 5.67, P = 0.025].

Conclusion: A strong reduction of alpha power in the posterior regions may reflect abnormality in the thalamocortical circuits. It is shown that hypoxia and reduced cerebral blood flow is associated with reduced alpha activity among different regions of the brain. Therefore, it can be concluded that greatly decreased alpha activity, particularly in centro-parietal and occipital regions, is related to SA symptoms such as hallucinations.


Alpha Activity, Electroencephalogram, Schizoaffective Disorder, Serotonin

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Khaleghi A, Sheikhani A, Mohammadi MR, Moti Nasrabadi A. Evaluation of Cerebral Cortex Function in Clients with Bipolar Mood Disorder I (BMD I) Compared With BMD II Using QEEG Analysis. Iran J Psychiatry 2015; 10: 93-99.

Khaleghi A, Sheikhani A, Mohammadi MR, Nasrabadi AM, Vand SR, Zarafshan H, et al. EEG classification of adolescents with type I and type II of bipolar disorder. Australas Phys Eng Sci Med 2015; 38: 551-559.

Moeini M, Khaleghi A, Mohammadi MR. Characteristics of Alpha Band Frequency in Adolescents with Bipolar II Disorder: A Resting-State QEEG Study. Iran J Psychiatry 2015; 10: 8-12.

Zarafshan H, Khaleghi A, Mohammadi MR, Moeini M, Malmir N. Electroencephalogram complexity analysis in children with attention-deficit/hyperactivity disorder during a visual cognitive task. J Clin Exp Neuropsychol 2016; 38: 361-369.

Mohammadi MR, Malmir N, Khaleghi A, Aminiorani M. Comparison of Sensorimotor Rhythm (SMR) and Beta Training on Selective Attention and Symptoms in Children with Attention Deficit/Hyperactivity Disorder (ADHD): A Trend Report. Iran J Psychiatry 2015; 10: 165-174.

Moeini M, Khaleghi A, Amiri N, Niknam Z. Quantitative electroencephalogram (QEEG) Spectrum Analysis of Patients with Schizoaffective Disorder Compared to Normal Subjects. Iran J Psychiatry 2014; 9: 216-221.

Association AP, Association AP. Diagnostic and statistical manual-text revision (DSM-IV-TRim, 2000). ed. editor^editors.: American Psychiatric Association; 2000.

Perala J, Suvisaari J, Saarni SI, Kuoppasalmi K, Isometsa E, Pirkola S, et al. Lifetime prevalence of psychotic and bipolar I disorders in a general population. Arch Gen Psychiatry 2007; 64: 19-28.

Bardenstein KK, McGlashan TH. Gender differences in affective, schizoaffective, and schizophrenic disorders. A review. Schizophr Res 1990; 3: 159-172.

Breuer R, Hamshere ML, Strohmaier J, Mattheisen M, Degenhardt F, Meier S, et al. Independent evidence for the selective influence of GABA(A) receptors on one component of the bipolar disorder phenotype. Mol Psychiatry 2011; 16: 587-589.

Craddock N, Jones L, Jones IR, Kirov G, Green EK, Grozeva D, et al. Strong genetic evidence for a selective influence of GABAA receptors on a component of the bipolar disorder phenotype. Mol Psychiatry 2010; 15: 146-153.

Harrow M, Grossman LS, Herbener ES, Davies EW. Ten-year outcome: patients with schizoaffective disorders, schizophrenia, affective disorders and mood-incongruent psychotic symptoms. Br J Psychiatry 2000; 177: 421-426.

Bartos M, Vida I, Jonas P. Synaptic mechanisms of synchronized gamma oscillations in inhibitory interneuron networks. Nat Rev Neurosci 2007; 8: 45-56.

Buzsaki G, Wang XJ. Mechanisms of gamma oscillations. Annu Rev Neurosci 2012; 35: 203-225.

Brealy JA, Shaw A, Richardson H, Singh KD, Muthukumaraswamy SD, Keedwell PA. Increased visual gamma power in schizoaffective bipolar disorder. Psychol Med 2015; 45: 783-794.

Meltzer HY, Arora RC, Metz J. Biological studies of schizoaffective disorders. Schizophr Bull 1984; 10: 49-70.

Pandey GN, Pandey SC, Ren X, Dwivedi Y, Janicak PG. Serotonin receptors in platelets of bipolar and schizoaffective patients: effect of lithium treatment. Psychopharmacology (Berl) 2003; 170: 115-123.

Celada P, Puig MV, Artigas F. Serotonin modulation of cortical neurons and networks. Front Integr Neurosci 2013; 7: 25.

Schellenberg R, Knorr W, Schindler M, Kropf S, Beyer H. EEG-power spectral components of schizoaffective disorders. Schizophr Res 1990; 3: 357-359.

Başar E. Brain Function and Oscillations: Volume I: Brain Oscillations. Principles and Approaches. ed. editor^editors.: Springer Science & Business Media; 2012.

Klimesch W, Sauseng P, Hanslmayr S. EEG alpha oscillations: the inhibition-timing hypothesis. Brain Res Rev 2007; 53: 63-88.

Jones NC, Reddy M, Anderson P, Salzberg MR, O'Brien TJ, Pinault D. Acute administration of typical and atypical antipsychotics reduces EEG gamma power, but only the preclinical compound LY379268 reduces the ketamine-induced rise in gamma power. Int J Neuropsychopharmacol 2012; 15: 657-668.

Takahashi T, Cho RY, Mizuno T, Kikuchi M, Murata T, Takahashi K, et al. Antipsychotics reverse abnormal EEG complexity in drug-naive schizophrenia: a multiscale entropy analysis. Neuroimage 2010; 51: 173-182.

Yamada K, Isotani T, Irisawa S, Yoshimura M, Tajika A, Yagyu T, et al. EEG Global Field Power spectrum changes after a single dose of atypical antipsychotics in healthy volunteers. Brain Topogr 2004; 16: 281-285.

Weiser M, Gershon AA, Rubinstein K, Petcu C, Ladea M, Sima D, et al. A randomized controlled trial of allopurinol vs. placebo added on to antipsychotics in patients with schizophrenia or schizoaffective disorder. Schizophr Res 2012; 138: 35-38.

Reist C, Wu JC, Lilja Y, Mukherjee J, Gripeos D, Constantinescu C, et al. Ketoconazole-associated preferential increase in dopamine D2 receptor occupancy in striatum compared to pituitary in vivo: role for drug transporters? J Clin Psychopharmacol 2012; 32: 110-113.

Robbins TW, Arnsten AF. The neuropsychopharmacology of fronto-executive function: monoaminergic modulation. Annu Rev Neurosci 2009; 32: 267-287.


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