Level 4: Efficacious
Multiple case studies have demonstrated clinically significant outcomes with carefully screened
and thoroughly assessed participants for various forms of anxiety-related disorders. There are also several
treatment-only group studies with moderate sample sizes, demonstrating positive results of various forms
of biofeedback that were often combined with other behavioral interventions. A few well-controlled,
randomized studies have shown biofeedback to be equivalent to other relaxation and self-control methods
for reducing anxiety while it is occasionally shown to be superior to another intervention. Most show
biofeedback (EMG, GSR, thermal, or neurofeedback) to be roughly equivalent to progressive relaxation
Lehrer, Carr, Sargunaraj, and Woolfolk (1994) evaluated the hypothesis that biofeedback is most
effective when applied in the same modality as the disorder (autonomic feedback for ANS disorders,
EMG feedback for muscular disorders, etc.). Other researchers have asserted self-relaxation techniques
have in common the process of using conscious intent to calm oneself, and for anxiety reduction, it may
matter little which modality is used because the central component is the cognitively based conscious
intent. Clarification of this issue must await further clinical outcome studies.
Two studies showed biofeedback’s efficacy in reducing anxiety without making comparisons
with other relaxation techniques. Hurley and Meminger (1992) used frontal EMG biofeedback with 40
subjects trained to criterion and assessed anxiety over time using the State-Trait Anxiety Inventory
(STAI). State anxiety improved more than trait anxiety. Wenck, Leu, and D’Amato (1996) trained 150
seventh- and eighth-graders with thermal and EMG feedback and found significant reduction in state and
Roome and Romney (1985) compared progressive muscle relaxation to EMG biofeedback
training with 30 children and found an advantage for biofeedback; however, Scandrett, Bean, Breeden,
and Powell (1986) found some advantage of progressive muscle relaxation over EMG biofeedback in
reducing anxiety in adult psychiatric inpatients and outpatients.
Rice, Blanchard, and Purcell (1993) studied reduction in generalized anxiety by comparing
groups given EMG frontal feedback, EEG alpha-increase feedback, and EEG alpha-decrease feedback to
two control conditions (a pseudo-meditation condition and a wait-list control). All treatment groups had
comparable and significant decreases in the STAI and drops in the Psychosomatic Symptom Checklist.
The alpha-increasing biofeedback condition produced one effect not found with the other treatment
conditions: a reduction in heart-rate reactivity to stressors. Similar results were obtained by Sarkar,
Rathee, and Neera (1999), who compared the generalized anxiety disorder response to pharmacotherapy
and to biofeedback; the two treatments had similar effects on symptom reduction. Hawkins, Doell,
Lindseth, Jeffers, and Skaggs (1980) concluded, from a study with 40 hospitalized schizophrenics, that
thermal biofeedback and relaxation instructions had an equivalent effect on anxiety reduction. However,
Fehring (1983) found adding GSR biofeedback to a Benson-type relaxation technique reduced anxiety
symptoms more than relaxation alone.
Vanathy, Sharma, and Kumar (1998), applying EEG biofeedback to generalized anxiety disorder,
compared increased alpha with increased theta. The two procedures were both effective in decreasing
symptoms. In a recent case study, Hammond (2003) reported on two cases using EEG biofeedback for
OCD. Clinically significant improvements for both participants were reported. In a single case study
(Goodwin & Montgomery, 2006) of a 39-year-old male with panic disorder and agoraphobia,
electrodermal biofeedback was combined with CBT, graded exposure. They reported a complete
cessation of panic attacks, a remission of agoraphobia, and a clinically significant reduction in depression.
In a study by Gordon, Staples, Blyta, and Bytyqi (2004) a total of 139 PTSD postwar high school
students were provided a six-week program of biofeedback, meditation, drawings, autogenics, guided
imagery, genograms, and breathing techniques. No control group was used, but they reported a significant
reduction immediately after treatment and at follow up. In a two-treatment group comparison study
(n=50) of anxiety in individuals with chronic pain, Corrado, Gottlieb, and Abdelhamid (2003) reported a
significant improvement in anxiety and somatic complaints in the group that received biofeedback of
finger temperature increase and muscle tension reduction when compared to a pain education group.