Visual sensory processing deficits in patients with bipolar disorder revealed through high-density electrical mapping

• Published in: Journal of psychiatry & neuroscience 2009-11, Vol.34 (6), p.459-464
• Main Authors: Yeap, Sherlyn, MRCPsych, Kelly, Simon P., PhD, Reilly, Richard B., PhD, Thakore, Jogin H., MD, PhD, Foxe, John J., PhD
• Format: Article
• Language: English
• Subjects: Adult; Adult and adolescent clinical studies; Behavioral sciences; Biological and medical sciences; Bipolar disorder; Bipolar Disorder - psychology; Bipolar disorders; Brain Mapping; Care and treatment; Electroencephalography; Electrophysiology; Female; Fundamental and applied biological sciences. Psychology; Humans; Male; Medical Education; Medical research; Medical sciences; Middle Aged; Mood disorders; Photic Stimulation; Physiological aspects; Psychiatric Status Rating Scales; Psychiatry; Psychoanalysis; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychomotor Performance - physiology; Psychopathology. Psychiatry; Research Paper; Schizophrenia; Visual Perception - physiology; Young Adult
• ISSN: 1180-4882; 1488-2434

Background Etiological commonalities are apparent between bipolar disorder and schizophrenia. For example, it is becoming clear that both populations show similar electrophysiological deficits in the auditory domain. Recent studies have also shown robust visual sensory processing deficits in patients with schizophrenia using the event-related potential technique, but this has not been formally tested in those with bipolar disorder. Our goal here was to assess whether early visual sensory processing in patients with bipolar disorder, as indexed by decreased amplitude of the P1 component of the visual evoked potential (VEP), would show a similar deficit to that seen in those with schizophrenia. Since the P1 deficit has already been established as an endophenotype in schizophrenia, a finding of commonality between disorders would raise the possibility that it represents a measure of common genetic liability. Methods We visually presented isolated-check stimuli to euthymic patients with a diagnosis of bipolar disorder and age-matched healthy controls within a simple go/no-go task and recorded VEPs using high-density (72-channel) electroencephalography. Results The P1 VEP amplitude was substantially reduced in patients with bipolar disorder, with an effect size of f = 0.56 (large according to Cohen’s criteria). Limitations Our sample size was relatively small and as such, did not allow for an examination of potential relations between the physiologic measures and clinical measures. Conclusion This reduction in P1 amplitude among patients with bipolar disorder represents a dysfunction in early visual processing that is highly similar to that found repeatedly in patients with schizophrenia and their healthy first-degree relatives. Since the P1 deficit has been related to susceptibility genes for schizophrenia, our results raise the possibility that the deficit may in fact be more broadly related to the development of psychosis and that it merits further investigation as a candidate endophenotype for bipolar disorder.