Abnormal brain oscillations persist after recovery from bipolar depression
P Canali1, S Casarotto2, M Rosanova3
1Department of clinical neurosciences, scientific institute Ospedale San Raffaele, university Vita-Salute San Raffaele, San Raffaele Turro, 20, via Stamira d'Ancona, 20127 Milano, Italy.
Summary
Reduced brain oscillations in bipolar disorder (BD) patients are a stable trait, not improving with antidepressant treatments like sleep deprivation and light therapy. Transcranial magnetic stimulation (TMS) combined with EEG revealed these persistent abnormalities, suggesting a potential biomarker for BD.
Area of Science:
- Neuroscience
- Psychiatry
- Biomarkers
Background:
- Premotor cortical areas in healthy individuals exhibit beta-range (20-40Hz) oscillations.
- Schizophrenia, major depressive disorder, and bipolar disorder (BD) are associated with reduced amplitude and frequency of these oscillations.
- It remains unclear if these abnormalities are treatable or persistent.
Purpose of the Study:
- To investigate the modulation of frontal oscillatory activity in bipolar disorder (BD) patients before and after antidepressant treatments.
- To determine if reduced oscillations in BD are a state or trait marker.
- To explore the utility of transcranial magnetic stimulation (TMS) combined with electroencephalography (EEG) as a biomarker.
Main Methods:
- Employed TMS combined with EEG to assess frontal oscillatory activity in 18 BD patients and 9 healthy controls.
- Utilized event-related spectral perturbations (ERSP) with wavelet decomposition to detect dominant frequencies.
- Calculated the natural oscillation frequency as the peak frequency within 300ms post-stimulus.
Main Results:
- Antidepressant treatments significantly reduced depression severity in BD patients.
- Healthy controls showed significant beta/gamma band activation (21-50Hz) post-TMS.
- BD patients exhibited significantly lower premotor EEG response frequencies (11-27Hz) compared to controls, with no significant change post-treatment.
- Patient frequencies were similar regardless of treatment response or remission status.
Conclusions:
- Reduced natural oscillation frequencies in premotor cortex appear to be a trait marker for bipolar disorder (BD), independent of clinical status.
- TMS-EEG is a valuable tool for identifying neurobiological underpinnings of psychiatric disorders and developing potential biomarkers.
- These findings contribute to understanding the neurobiology of severe psychiatric conditions.
Related Concept Videos
01:30Bipolar Disorder
1.2K
Bipolar disorder is a chronic mental health condition marked by significant mood fluctuations, including episodes of mania and depression. Elevated energy levels, heightened mood or irritability, impulsive behavior, reduced sleep needs, rapid speech, racing thoughts, inflated self-esteem, and distractibility characterize mania. Individuals with bipolar disorder often alternate between depressive and manic states, with periods of emotional stability lasting an average of six months to a year.
1.2K
01:23Brain Waves
4.5K
Brain waves are electrical signals generated by the neurons in the brain, which are regularly monitored to measure mental activities. Brain waves and their frequency ranges can be measured using an electroencephalogram or EEG. There are four main types of brain waves, each with distinct characteristics:
4.5K
01:24Mania and Antimanic Drugs: Overview
719
Mania, a psychological condition characterized by elevated mood, increased energy, and reduced sleep need, is part of the bipolar disorder cycle. The exact cause of mania isn't entirely known, but it is thought to be a combination of genetic, environmental, and neurological factors. Bipolar disorder involves alternating manic and depressive episodes. Mood stabilizers like lithium, antipsychotics, and anticonvulsants help manage these episodes. Lithium carbonate is particularly effective as...
719
01:27Psychosis: Pathophysiology of Schizophrenia and Other Psychotic Disorders
2.3K
Schizophrenia is a neurodevelopmental disorder whose origins are rooted in complex genetic components. Despite our burgeoning understanding, the pathophysiology of this disorder remains incompletely deciphered.
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within...
Researchers have identified genetic factors that increase susceptibility to schizophrenia, underscoring the intricate interplay between genetics and environment in disease development. At the core of schizophrenia's pathophysiology is excessive dopaminergic neurotransmission within...
2.3K
01:30Electroconvulsive Therapy
1.7K
Electroconvulsive therapy (ECT), or shock therapy, remains a critical biomedical intervention for severe, treatment-resistant depression. While its origins can be traced back to Hippocrates' observations that malaria-induced convulsions alleviated mental illness, modern ECT has evolved significantly from its earlier, more primitive applications. First introduced in 1938 by Ugo Cerletti and his colleagues, ECT involves inducing controlled seizures using electrical currents. In its early...
1.7K