Prefrontal Cortex Stimulation as Treatment for Crack-cocaine Addiction
Condition: Cocaine Addiction; Cocaine-related Disorder; Executive Dysfunction
MeSH terms: Cocaine-Related Disorders; Behavior, Addictive
Study type: Interventional
Phase: Phase 1/Phase 2

Summary: 
      The use of crack-cocaine is growing at alarming rate in our country and it is absolutely
      worrisome the fast establishment of addiction to it. Its immediate effects, that are intense
      and extremely fleeting, increase dramatically the probability of this drug to be consumed
      again, settling quickly down the loss of control and the compulsive use, turning the effects
      of this drug highly addictive. Parallel to this process, brain damages are quickly
      established, progressing to severe impairments of frontal functions, leading to the lack of
      cognitive control that feeds back and aggravates the dependence, and hampers any therapeutic
      approach. The existing treatments have not proved to be satisfactory yet. Thus, considering
      that a new modality of treatment, based on the neuromodulation induced by noninvasive brain
      stimulation, has been useful in treating various neuropsychiatric conditions, this study will
      examine the potential beneficial effects of repeated transcranial Direct Current Stimulation
      over the left dorsolateral prefrontal cortex in the treatment of crack-cocaine addiction.
    

Detailed description: 
      Forty subjects between 18 and 60 years old, both genders, with a diagnosis of dependence on
      crack-cocaine, evaluated for the first time at the Center for Psychosocial Care for Alcohol
      and Other Drugs (CAPS-AD, in Portuguese) in the municipality of Serra, ES, Brazil, will be
      invited to participate in this study. After triage, following the inclusion and exclusion
      criteria, they will be informed in details about the experimental protocol and, if they agree
      to participate, it will be required to sign an Informed Consent. It Will be applied a
      structured anamnesis, made a psychiatric clinical and physical examination. The treatment
      will be started with regular medications for abstinence and comorbidities and psychosocial
      approaches usually done in the CAPS-AD. After selected they will be referred to the
      Laboratory of Cognitive Science and Neuropsychopharmacology of the Postgraduate Program in
      Physiological Sciences from Health Sciences Center of Federal University of Espírito Santo
      where they will be semi-randomly (matched for age, gender and sociodemographic
      characteristics) distributed into two different groups: (A) sham-tDCS (n = 20) and (B)
      active-tDCS (n = 20); and they will follow for 10 applications in daily sessions, excepting
      on weekends, of transcranial direct current stimulation (tDCS, 5 x 7 cm2, 2 mA, 20 min) over
      the left dorsolateral prefrontal cortex or sham procedure. Event-related potentials (ERP)
      will be recorded before, during and after brain stimulation or sham procedure under random
      presentation of three related images and three non-related images to crack use. The
      compulsive behavior will be evaluated before and after the ERP records. Cognitive tests which
      assess mental function, frontal function, visuospatial and verbal working memory, inhibition,
      and conflict resolution will be performed. The depression will be assessed during the
      treatment, and the addicted subjects will be evaluated once a week for four consecutive weeks
      after a series of applications of sham-tDCS or active-tDCS.
    

Intervention name(s): transcranial Direct Current Stimulation
Intervention type(s): Device
Intervention description(s): transcranial Direct Current Stimulation (tDCS) will be applied by electrodes (5 x 7 cm2), with intensity of 2 mA, during 20 min, with cathode over the left dorsolateral prefrontal cortex (F3 site) and anode placed in the contralateral dorsolateral prefrontal cortex (F4 site).
Other intervention name(s): brain stimulation; non-invasive brain stimulation
Allocation: Randomized
Intervention model: Parallel Assignment
Masking: Triple (Participant, Care Provider, Investigator)
Primary purpose: Treatment
Keywords: crack cocaine; addiction; tDCS; ERP; P300; attention; inhibitory control; working memory