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Current Treatment Options in Psychiatry
C H A P T E R
7.4
Current Treatment Options in Psychiatry The modern psychiatry has in its arsenal different treatment options including pharmacotherapy, neurotherapy, and neuromodulation techniques. The basic idea of the pharmacotherapy is that the core of the brain functioning is chemical so that mental illness is the result of imbalances among neurotransmitters. Consequently, the main goal for pharmacology is to find a neurotransmitter system involved in a given psychopathology. Taken into account high heterogeneity of functional proteins (receptors, transporters, ion channels, enzymes) in the brain, the number of selective pharmaceutical agents used by mental health care is supposed to be big. However during the last years, the psychopharmacology faced a certain crisis and shrinked neuroscience research projects. Neurotherapy and neuromodulation options emerged as alternative approaches for curing mental illness. Neurofeedback (NF) is a technique of a self-regulation in which current parameters of EEG recorded from the subject’s head are presented to a subject through visual, auditory, or tactile modality while the subject is supposed to alter these parameters to reach a more efficient mode of brain functioning. According to the two types of electrical brain phenomena there are two main types of neurofeedback: conventional EEG biofeedback (including LORETA NF) and infralow frequency (ILF) neurofeedback. The conventional NF uses the spectral characteristics of EEG in 0.5–50 Hz frequency band whereas the ILF NF uses either amplitude itself or phase of the voltage fluctuations below 0.1 Hz. ILF NF is done in discrete and continuous forms. In contrast to the “one size fits all,” discrete protocol the continuous ILF protocols are different for different symptoms. The protocols of the conventional NF can be divided into activation and relaxation protocols. The neurofeedback of at the beginning (middle of 20th century) was driven by the theory of operant conditioning, but recently a bulldozer principle has been suggested with the aim to normalize
Functional Neuromarkers for Psychiatry. http://dx.doi.org/10.1016/B978-0-12-410513-3.00040-1 Copyright © 2016 Elsevier Inc. All rights reserved.
411
412 7.4. Current Treatment Options in Psychiatry a pathologically abnormal EEG pattern. NF should not be applied without relevant diagnostic procedures of QEEG and ERPs. Electroconvulsive therapy (ECT) is the oldest nonpharmacological therapy currently available for psychiatric disease. Electrodes are placed either unilaterally or bilaterally with electric pulses of 500–800 mA. Mechanisms of the therapeutic effect of ECT are not known. ECT is frequently associated with retrograde and anterograde amnesia. Relapse after a successful ECT course is a major limitation of the therapy. In transcranial direct current stimulation (tDCS) a small amount of direct electric current (1–2 mA) is applied to the skin of the head by two relatively large electrodes. The electric current flows according to the Ohm’s law and depolarizes/hyperpolarizes pyramidal cells at their basal membrane depending on direction of the current. tDCS is fundamentally different from ECT by inducing much smaller currents which do not evoke action potentials but change overall neuronal activity due to collective effects. tDCS long-term aftereffect is a function of the intensity and duration of tDCS application and occurs through NMDA-dependent mechanisms similar to long-term synaptic potentiation and depression. When applied according to standard requirements, the tDCS is a safe procedure. Transcranial magnetic stimulation (TMS) is based on the law of electromagnetic induction. In TMS, a pulse of electric current passing through a coil placed over a subject’s head generates a rapidly changing magnetic pulse that penetrates the scalp and skull to reach the cortex with negligible attenuation. The pulse of magnetic field in turn induces a secondary ionic current in the brain which can trigger action potentials in cortical neurons. TMS in clinical practice is applied in form of continuous trains and is named repetitive TMS (rTMS). rTMS can induce changes in neuronal excitability that persist beyond the time of stimulation. These neuromodulatory effects of TMS are used in patients with neurologic and psychiatric diseases to maintain or restore brain functions. rTMS is reasonably safe with mild side effects when performed in compliance with the recommended safety guidelines. At the beginning of 20th century, psychosurgery for severe psychiatric conditions aimed in destruction of large portions of the brain. In the mid of 20th century, it was replaced by stereotactic local lesions. Currently deep brain stimulation (DBS) substitutes these ablation techniques. Effects of DBS are fully reversible and can be adjusted to patients’ symptoms.
7. THE STATE OF THE ART: OVERVIEW
7.4
Current Treatment Options in Psychiatry The modern psychiatry has in its arsenal different treatment options including pharmacotherapy, neurotherapy, and neuromodulation techniques. The basic idea of the pharmacotherapy is that the core of the brain functioning is chemical so that mental illness is the result of imbalances among neurotransmitters. Consequently, the main goal for pharmacology is to find a neurotransmitter system involved in a given psychopathology. Taken into account high heterogeneity of functional proteins (receptors, transporters, ion channels, enzymes) in the brain, the number of selective pharmaceutical agents used by mental health care is supposed to be big. However during the last years, the psychopharmacology faced a certain crisis and shrinked neuroscience research projects. Neurotherapy and neuromodulation options emerged as alternative approaches for curing mental illness. Neurofeedback (NF) is a technique of a self-regulation in which current parameters of EEG recorded from the subject’s head are presented to a subject through visual, auditory, or tactile modality while the subject is supposed to alter these parameters to reach a more efficient mode of brain functioning. According to the two types of electrical brain phenomena there are two main types of neurofeedback: conventional EEG biofeedback (including LORETA NF) and infralow frequency (ILF) neurofeedback. The conventional NF uses the spectral characteristics of EEG in 0.5–50 Hz frequency band whereas the ILF NF uses either amplitude itself or phase of the voltage fluctuations below 0.1 Hz. ILF NF is done in discrete and continuous forms. In contrast to the “one size fits all,” discrete protocol the continuous ILF protocols are different for different symptoms. The protocols of the conventional NF can be divided into activation and relaxation protocols. The neurofeedback of at the beginning (middle of 20th century) was driven by the theory of operant conditioning, but recently a bulldozer principle has been suggested with the aim to normalize
Functional Neuromarkers for Psychiatry. http://dx.doi.org/10.1016/B978-0-12-410513-3.00040-1 Copyright © 2016 Elsevier Inc. All rights reserved.
411
412 7.4. Current Treatment Options in Psychiatry a pathologically abnormal EEG pattern. NF should not be applied without relevant diagnostic procedures of QEEG and ERPs. Electroconvulsive therapy (ECT) is the oldest nonpharmacological therapy currently available for psychiatric disease. Electrodes are placed either unilaterally or bilaterally with electric pulses of 500–800 mA. Mechanisms of the therapeutic effect of ECT are not known. ECT is frequently associated with retrograde and anterograde amnesia. Relapse after a successful ECT course is a major limitation of the therapy. In transcranial direct current stimulation (tDCS) a small amount of direct electric current (1–2 mA) is applied to the skin of the head by two relatively large electrodes. The electric current flows according to the Ohm’s law and depolarizes/hyperpolarizes pyramidal cells at their basal membrane depending on direction of the current. tDCS is fundamentally different from ECT by inducing much smaller currents which do not evoke action potentials but change overall neuronal activity due to collective effects. tDCS long-term aftereffect is a function of the intensity and duration of tDCS application and occurs through NMDA-dependent mechanisms similar to long-term synaptic potentiation and depression. When applied according to standard requirements, the tDCS is a safe procedure. Transcranial magnetic stimulation (TMS) is based on the law of electromagnetic induction. In TMS, a pulse of electric current passing through a coil placed over a subject’s head generates a rapidly changing magnetic pulse that penetrates the scalp and skull to reach the cortex with negligible attenuation. The pulse of magnetic field in turn induces a secondary ionic current in the brain which can trigger action potentials in cortical neurons. TMS in clinical practice is applied in form of continuous trains and is named repetitive TMS (rTMS). rTMS can induce changes in neuronal excitability that persist beyond the time of stimulation. These neuromodulatory effects of TMS are used in patients with neurologic and psychiatric diseases to maintain or restore brain functions. rTMS is reasonably safe with mild side effects when performed in compliance with the recommended safety guidelines. At the beginning of 20th century, psychosurgery for severe psychiatric conditions aimed in destruction of large portions of the brain. In the mid of 20th century, it was replaced by stereotactic local lesions. Currently deep brain stimulation (DBS) substitutes these ablation techniques. Effects of DBS are fully reversible and can be adjusted to patients’ symptoms.
7. THE STATE OF THE ART: OVERVIEW