Atlanta Depression Pain | Atlanta Pain Doctors

The Atlanta Pain Doctors provide transcranial direct current stimulation (tDCS) as an adjuvant therapy for mild, moderate, severe and treatment-resistant depression. Five 30-minute treatments done on consecutive days can reduce the symptoms of depression up to 70% and 1 month later the symptoms are even less.

Major depressive disorder (MDD)

Major depressive disorder (MDD) is a common incapaciting condition. In addition, depression is a chronic, recurrent disorder, as 60-80% of patients relapse after the treatment of an episode. Finally, 1/3 of patients have treatment-resistant depression (TRD), which is defined as the failure to achieve adequate response of symptoms after two or more antidepressant treatments.

There are several hypotheses to explain the pathophysiology of MDD.

One important and usually highly cited hypothesis of MDD is the monoamine hypothesis, which suggests that MDD symptoms are related to low concentrations of monoamines (serotonin, norepinephrine, dopamine). But this is not sufficient to explain observations – for example, the time lag of antidepressants for therapeutic action, and that symptoms of MDD do not directly relate with the monoamines.A more recent hypothesis is the neuroplastic hypothesis that describes patients with MDD having decreased plasticity that obstructs the creation of new synapses in areas associated with positive emotional processing.

These two previous hypotheses have led to another: the neural system hypothesis. Neuroimaging techniques show that specific brain areas have a lower volume in depressed patients. In addition, functional studies suggest a low level of activity in the dorso-lateral prefrontal cortex (DLPFC), the left motor cortex and a higher brain activity in the right cortex. These findings suggest a “differential activity” of certain brain areas in patients with MDD, which can explain some symptoms of depression: for instance, psychomotor retardation and executive function impairment (related to the DLPFC) and negative emotional judgment (related to left-right imbalance).

Taken together, these hypotheses support the notion that MDD is a disorder associated with dysfunction in critical areas related to mood regulation. In fact, two major pathways can be determined here: the cognitive-executive pathway, in which a hypoactive DLPFC fails to regulate areas related to executive functioning; and the affective-somatic pathway related to negative affect and self-awareness. The rationale in using different neurostimulation therapies is based on their mechanisms of inhibiting or enhancing activity in these pathways.

Electreoconvulsive therapy (ECT)

Electreoconvulsive therapy (ECT) is the first and most studied brain stimulation therapy to date. Accumulated evidence indicates that its antidepressants effects are related to several mechanisms, such as restoring hemispheric balance, enhancing neurogenesis through a series of electrical shocks and, long-term up-regulation of serotonin activity. With ECT, 600-1000 mA of electricity is used to induce a grand mal seizure. 8-9 ECT treatments are necessary to produce results. The negative cognitive effects of ECT are well known: important decreases in performance in almost all neuropsychological tests, especially in women.

Repetitive transcranial magnetic stimulation (rTMS)

Repetitive transcranial magnetic stimulation (rTMS) uses the principle of electromagnetic induction to focus induced current in the brain. It is hypothesized that high-frequency TMS acts by increasing activity in the left DLPFC area, thus ameliorating depression symptoms. Low-frequency rTMS, on the other hand, modifies interhemispheric imbalance – i.e., as MDD might be associated with an imbalance in prefrontal cortex activity, decreasing the right DLPFC activity “releases” the left DLPFC.

rTMS had the same efficacy as the pharmacologic drugs for MDD, also with similar rates of response and remission. Currently, rTMS is only approved in the US to treat patients who failed to respond to at least one antidepressant trial.

Transcranial direct current stimulation (tDCS)

Transcranial direct current stimulation (tDCS) is a new method of non-invasive brain modulation. It is based on a transcranial application of weak direct currents (usually 1 mA) via scalp electrodes in a non-invasive, simple and painless manner. The effects are polarity-dependent: while anodal stimulation induces an enhancement on cortical excitability, cathodal stimulation decreases it. These effects are explained as related to shifting on membrane resting potential (depolarization or hyperpolarization, respectively). Finally, the effects are also related to the stimulated area.The investigation on the effects of tDCS as an antidepressant therapy dates from the 1960s. In the last decade new protocols of tDCS for depression have been developed.

tDCS demonstrates antideprssant effects for patients with mild, moderate, severe and treatment-resistant depression. In addition, repeated sessions of tDCS can prolong its therapeutic effects.

Regarding tDCS, a study by Fregni showed that 5 days of anodal stimulation over the left DLPFC reduced the symptoms of depression 70% and resulted in no deleterious effects on memory, attention, language and executive functions. Instead, an improvement in working memory was found. The same author also found that anodal tDCS (2 mA) applied over the left DLPFC of patients with Parkinson’s disease resulted in an improvement in working memory.

The “user-friendly” approach of tDCS (i.e., low cost, absence of side effects, portability and ability to be operated by the patient or relative) is a promising alternative to treat a wide range of depressed patients.

REFERENCES:
Transcranial Direct Current Stimulation (tDCS) for Depression:

“The continuous research of novel neuromodulation techniques is showing promising results and therefore the attending physician should consider them as alternatives when treating a depressed patient.” Neuromodulation approaches for the treatment of major depression: challenges and recommendations from a working group meeting. Brunoni AR, Teng CT, Correa C, Imamura M, Brasil-Neto JP, Boechat R, Rosa M, Caramelli P, Cohen R, Del Porto JA, Boggio PS, Fregni F. Arq Neuropsiquiatr. 2010 Jun;68(3):433-51.
“Overall depression scores improved significantly over ten 20-minute tDCS treatments. tDCS was found to be safe, with no adverse effects on neuropsychological function, and only minor side-effects.” A double-blind, sham-controlled trial of transcranial direct current stimulation for the treatment of depression. Loo CK, Sachdev P, Martin D, Pigot M, Alonzo A, Malhi GS, Lagopoulos J, Mitchell P. Int J Neuropsychopharmacol. 2009 Aug 12:1-9.

“In fact, two recent trials have shown that tDCS is associated with significant clinical gains.” Transcranial direct current stimulation as a therapeutic tool for the treatment of major depression: insights from past and recent clinical studies. Murphy DN, Boggio P, Fregni F. Curr Opin Psychiatry. 2009 May;22(3):306-11. Berenson-Allen Center for Noninvasive Brain Stimulation, Department of Neurology, Beth Israel Deaconess Medical Center, Harvard Medical School.

“After five days of tDCS treatment depression scores improved more than 30%. The mood improvement persisted and even increased at four weeks after treatment ended. We conclude that frontal tDCS is a simple technique that can be considered in clinical practice as adjuvant treatment for patients with severe, drug-resistant major depression.” Transcranial direct current stimulation in severe, drug-resistant major depression. Ferrucci R, Bortolomasi M, Vergari M, Tadini L, Salvoro B, Giacopuzzi M, Barbieri S, Priori A. J Affect Disord. 2009 Nov;118(1-3):215-9.

Transcranial direct current stimulation: a new tool for the treatment of depression. Arul-Anandam AP, Loo C. J Affect Disord. 2009 Oct;117(3):137-45.

“Citalopram enhanced and prolonged the facilitation induced by anodal tDCS.” Serotonin affects transcranial direct current-induced neuroplasticity in humans. Nitsche MA, Kuo MF, Karrasch R, Wächter B, Liebetanz D, Paulus W. Biol Psychiatry. 2009 Sep 1;66(5):503-8.

“The treatment was well tolerated with minimal side-effects. We found large reductions in depression scores after tDCS of 40.4%. The beneficial effects of tDCS persisted for 1 month after the end of treatment.” A randomized, double-blind clinical trial on the efficacy of cortical direct current stimulation for the treatment of major depression. Boggio PS, Rigonatti SP, Ribeiro RB, Myczkowski ML, Nitsche MA, Pascual-Leone A, Fregni F. Int J Neuropsychopharmacol. 2008 Mar;11(2):249-54.

“tDCS reduced the symptoms of depression 70%.” Treatment of major depression with transcranial direct current stimulation. Fregni F, Boggio PS, Nitsche MA, Marcolin MA, Rigonatti SP, Pascual-Leone A. Bipolar Disord. 2006 Apr;8(2):203-4.

Transcranial direct current stimulation: a new treatment for depression. Nitsche MA. Bipolar Disord. 2002;4 Suppl 1:98-9.

“tDCS has a good potential as a complementary tool in the treatment of anorexia.” Transcranial direct current stimulation in the treatment of anorexia. Hecht D. Med Hypotheses. 2010 Jun;74(6):1044-7. Institute of Cognitive Neuroscience, University College London, London, UK.

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