The Effectiveness of Transcranial Direct Current Stimulation (tDCS) in Decreasing Food Cravings
Condition: Craving
Study type: Interventional

Summary: 
      This study aims to evaluate the effectiveness of transcranial direct current stimulation
      (tDCS) in decreasing food cravings. Specifically, this study will determine whether healthy
      subjects will report decreased food craving following a single 20-minute session of tDCS
      (compared to sham tDCS) delivered during and immediately following the exposure to food
      stimuli.
    

Detailed description: 
      Recently, the use of low amplitude direct current stimulation of the human cortex has
      received attention as a possible for treatment for depression and pain (Been et al, 2007).
      This technique (called transcranial direct current stimulation or tDCS) involves the
      placement of two sponge electrodes over separate areas of the scalp. tDCS has been shown to
      be capable of changing the excitability of the superficial neurons immediately beneath the
      sponge electrodes. Evidence suggests that anodal stimulation is associated with increased
      cortical excitability and cathodal stimulation is associated with decreased cortical
      excitability (Been et al, 2007).

      Brain imaging studies are beginning to elucidate the functional neuroanatomy of cravings
      (George, Anton, Bloomer, Teneback, Drobes, Lorberbaum, et al., 2001; Myrick, Anton, Li,
      Henderson, Drobes, Voronin, et al., 2004). While the role of the prefrontal cortex in
      regulating cravings remains somewhat unclear, frontal cortical areas appear to be involved in
      integrating incoming sensory information (such as sights, smells, and sounds) with
      affective/emotional information in the brain, and may be involved in regulating emotional
      reactions to various stimuli (Alexander, DeLong, & Strick, 1986; Lorenz, Minoshima, & Casey,
      2003). The dorsal lateral prefrontal cortex may become activated when an individual is
      presented with cues that trigger reward memories associated with certain consumptive
      behaviors (Anton, 1999). One fMRI study found that when alcoholic subjects were presented
      with alcohol related cues, there was greater activation in the left prefrontal cortex and
      anterior thalamus, compared to when they viewed non-alcohol cues (George et al., 2001). Other
      studies on bulimia and drug cravings have identified hyperactivity in the orbitofrontal
      cortex and anterior cingulate cortex associated with increases in cravings ratings (Goldstein
      & Volkow, 2002; Uher, et al., 2004).

      Very few studies have attempted to directly manipulate activation of brain structures that
      might be involved in cravings. tDCS allows researchers to selectively activate or inhibit
      different brain structures that might play a role in craving behaviors. Previous research
      with manipulating the activation of brain structures found that alcohol cravings decreased
      among individuals with alcohol dependence who received either left or right anodal
      stimulation of the dorsolateral prefrontal cortex (Boggio et al., 2008). This finding,
      combined with prior functional neuroanatomical work, and research on the relation of food
      cravings and nicotine cravings suggesting they share a common biologic mechanism (Pepino,
      Finkbiener, Menella 2009, 2007), suggests that the prefrontal cortex may be a reasonable
      preliminary tDCS cortical target for potentially inhibiting food cravings.

      To date, there has only been one published study examining the relationship between tDCS and
      food craving. Fregni and colleagues (2008) found cravings to be reduced by anode
      right/cathode left tDCS and cravings did not increase after anode left/cathode right tDCS.
      The evidence on the effectiveness of tDCS for decreasing food craving indicates relatively
      short-lived effects (lasting only a few weeks). While this may ultimately limit the utility
      of tDCS, it may have a place in the prevention and management of obesity.

      This study aims to evaluate the effectiveness of transcranial direct current stimulation
      (tDCS) in decreasing food cravings. Specifically, this study will determine whether healthy
      subjects will report decreased food craving following a single 20-minute session of tDCS
      (compared to sham tDCS) delivered during and immediately following the exposure to food
      stimuli.
    

Intervention name(s): real tDCS; sham tDCS
Intervention type(s): Device; Device
Intervention description(s): transcranial direct current stimulation; transcranial direct current stimulation
Allocation: Randomized
Intervention model: Crossover Assignment
Masking: Single (Participant)
Primary purpose: Other
Keywords: food cravings