Mindfulness Based Cognitive Therapy in Bipolar Disorder
Mindfulness Based Cognitive Therapy in Bipolar Disorder
Twenty-one participants were recruited for the present study. Twelve individuals with bipolar I in euthymic state (37 ± 7.3 yrs, 10 females and 2 males, manic episodes 2.8 ± 2.6, depressive episodes 2.8 ± 3.0) and 9 control individuals (29 ± 6.4 yrs, 7 females and 2 males) with no prior psychiatric history and no first degree relatives with bipolar diagnoses. The study was approved by the Faculty of Health Sciences Human Ethics Committee of the University of Cape Town, and the participants signed informed consent (UCT HSF HREC 078/2009). The study was conducted in accordance with the Declaration of Helsinki, 2000.
All BD participants were medicated. All BD participants were receiving mood stabilizers, 8 of which were receiving lithium. Other prescribed medications included antipsychotics (8 participants), antidepressant (2 participants), and or anxyolytic (2 participants) medications. Co morbidities present in the BD cohort included: impulse control disorders (1 participant with trichotillomania and with compulsive buying, 1 participant with compulsive buying), anxiety disorders (3 participants with panic disorder and agoraphobia), and substance abuse disorders (1 participant with a past history of alcohol and cannabis dependence, 1 participant with a past history of benzodiazepine and diet pill dependency, 1 participant with current alcohol abuse).
Each of the participants underwent a structured clinical interview (SCID), to confirm diagnosis in bipolar group, and exclude mood disorders in the control group. Each of the participants underwent continuous electroencephalographic (EEG) record of their brain wave activity, at rest with eyes open for 3 min, with eyes closed for 3 min, and during a continuous performance task of approximately 10 min long. The bipolar participants completed an 8 week MBCT intervention. After the MBCT intervention the participants with bipolar disorder completed the EEG protocol again.
On each day of the EEG study, clinical scales were administered; these included the Young Mania Rating Scale (YMRS) and the Hospital Anxiety and Depression Scale (HADS) in order to confirm mood state. The EEG record was obtained within an hour session, between 09 h00 and 13 h30. The EEG session was completed in a quiet, dimly lit room to reduce distraction. The researcher conducting the experiments was with the participant at all times during the testing. All stages of the testing session were programmed in Eprime 1.1, which sent digital inputs of stimuli to Acqknowledge 4.1 (Biopac Systems Inc.) software, via an MP150 Biopac acquisition system, that also collected the EEG data (EEG 100 C amplifier modules).
A visual A-X continuous performance task was completed by the participants. Participants were required to respond with button press on presentation of the letter X if preceded by the letter A. All non target stimuli were letters of the alphabet other than A and X and did not include any vowels, to prevent word formation of randomly presented letters. Inter-stimuli intervals were set to 1000 msec, duration of target and non-target stimuli were for 500 msec. Fifty target stimuli were presented during the task.
EEG data was recorded with the use of a bioamplifier system produced by Biopac Systems Incorporated (MP150 system with 10 EEG100C amplifiers). The data was stored and processed with Acqknowledge 4.1 software from Biopac Systems Inc. A standard 10/20 linked ears reference montage EEG system was used, and individuals were grounded peripherally. Brain frequency activity and event-related potentials (ERPs) were obtained from: F3, F4, C3, C4, P3, and P4. The data was sampled at 500 Hz and band pass filtered FIR with a Hamming window (0.5 - 30 Hz). Electrooculogram (EOG) electrodes were used to assist in removal of EOG artifact, through an automated independent component analysis within Acqknowledge 4.1.
To obtain relative frequency power the data underwent Fast Fourier transform after channel filtering for resting conditions (eyes open and eyes closed) and the continuous performance task. Absolute power values were obtained and the relative values for theta (θ, 4–7 Hz), alpha (α, 7–14 Hz), and beta (β, 15–30 Hz) frequency bands were reported.
To obtain the ERP waveforms during the sustained attention task, epochs 200 msec prior to stimulus and 800 msec post target presentation were extracted to give a 1 sec window. This was also performed for both the target (letter X) and the cue (letter A). The extraction was set to reject ERPs that were greater than or less than 100 μV. This was followed by visual inspection of the average ERP for each participant. Each ERP was baseline corrected for 200 msec prior to stimulus presentation. The prominent wave components extracted during the target: early positive component (0–100 msec window), negative component (200–400 msec window), and late positive component (300–500 msec window). During the cue, P300-like wave component was extracted (200–400 msec window).
The MBCT intervention for BD was developed from the 8-week MBCT program for major depression. Specifically, the 8-week MBCT intervention for BD included psycho-education with a specific focus on mania and the early warning signs of mania and depression. During their participation in the present study, participants were encouraged to continue with all of their outpatient appointments, medications and other services they were receiving. None of the participants reported using non-MBCT meditation or yoga for therapeutic purpose during their participation in the present study. The MBCT intervention was led by an experienced therapist with recognized expertise in the delivery of cognitive therapy and MBCT.
Statistica 10 was used for the statistical analyses. Independent-sample t-tests were performed between control participants and individuals with bipolar disorder. Dependent-sample t-tests were performed between the individuals with bipolar prior and post their mindfulness based intervention. No further analyses were performed due to the pilot nature of these data. Data were reported as mean ± STDEV, significant values p < 0.05 and when refer to tendencies p < 0.1.
Methods
Participants
Twenty-one participants were recruited for the present study. Twelve individuals with bipolar I in euthymic state (37 ± 7.3 yrs, 10 females and 2 males, manic episodes 2.8 ± 2.6, depressive episodes 2.8 ± 3.0) and 9 control individuals (29 ± 6.4 yrs, 7 females and 2 males) with no prior psychiatric history and no first degree relatives with bipolar diagnoses. The study was approved by the Faculty of Health Sciences Human Ethics Committee of the University of Cape Town, and the participants signed informed consent (UCT HSF HREC 078/2009). The study was conducted in accordance with the Declaration of Helsinki, 2000.
All BD participants were medicated. All BD participants were receiving mood stabilizers, 8 of which were receiving lithium. Other prescribed medications included antipsychotics (8 participants), antidepressant (2 participants), and or anxyolytic (2 participants) medications. Co morbidities present in the BD cohort included: impulse control disorders (1 participant with trichotillomania and with compulsive buying, 1 participant with compulsive buying), anxiety disorders (3 participants with panic disorder and agoraphobia), and substance abuse disorders (1 participant with a past history of alcohol and cannabis dependence, 1 participant with a past history of benzodiazepine and diet pill dependency, 1 participant with current alcohol abuse).
Experimental Design
Each of the participants underwent a structured clinical interview (SCID), to confirm diagnosis in bipolar group, and exclude mood disorders in the control group. Each of the participants underwent continuous electroencephalographic (EEG) record of their brain wave activity, at rest with eyes open for 3 min, with eyes closed for 3 min, and during a continuous performance task of approximately 10 min long. The bipolar participants completed an 8 week MBCT intervention. After the MBCT intervention the participants with bipolar disorder completed the EEG protocol again.
On each day of the EEG study, clinical scales were administered; these included the Young Mania Rating Scale (YMRS) and the Hospital Anxiety and Depression Scale (HADS) in order to confirm mood state. The EEG record was obtained within an hour session, between 09 h00 and 13 h30. The EEG session was completed in a quiet, dimly lit room to reduce distraction. The researcher conducting the experiments was with the participant at all times during the testing. All stages of the testing session were programmed in Eprime 1.1, which sent digital inputs of stimuli to Acqknowledge 4.1 (Biopac Systems Inc.) software, via an MP150 Biopac acquisition system, that also collected the EEG data (EEG 100 C amplifier modules).
Sustained Attentional Task
A visual A-X continuous performance task was completed by the participants. Participants were required to respond with button press on presentation of the letter X if preceded by the letter A. All non target stimuli were letters of the alphabet other than A and X and did not include any vowels, to prevent word formation of randomly presented letters. Inter-stimuli intervals were set to 1000 msec, duration of target and non-target stimuli were for 500 msec. Fifty target stimuli were presented during the task.
Electroencephalography (EEG)
EEG data was recorded with the use of a bioamplifier system produced by Biopac Systems Incorporated (MP150 system with 10 EEG100C amplifiers). The data was stored and processed with Acqknowledge 4.1 software from Biopac Systems Inc. A standard 10/20 linked ears reference montage EEG system was used, and individuals were grounded peripherally. Brain frequency activity and event-related potentials (ERPs) were obtained from: F3, F4, C3, C4, P3, and P4. The data was sampled at 500 Hz and band pass filtered FIR with a Hamming window (0.5 - 30 Hz). Electrooculogram (EOG) electrodes were used to assist in removal of EOG artifact, through an automated independent component analysis within Acqknowledge 4.1.
To obtain relative frequency power the data underwent Fast Fourier transform after channel filtering for resting conditions (eyes open and eyes closed) and the continuous performance task. Absolute power values were obtained and the relative values for theta (θ, 4–7 Hz), alpha (α, 7–14 Hz), and beta (β, 15–30 Hz) frequency bands were reported.
To obtain the ERP waveforms during the sustained attention task, epochs 200 msec prior to stimulus and 800 msec post target presentation were extracted to give a 1 sec window. This was also performed for both the target (letter X) and the cue (letter A). The extraction was set to reject ERPs that were greater than or less than 100 μV. This was followed by visual inspection of the average ERP for each participant. Each ERP was baseline corrected for 200 msec prior to stimulus presentation. The prominent wave components extracted during the target: early positive component (0–100 msec window), negative component (200–400 msec window), and late positive component (300–500 msec window). During the cue, P300-like wave component was extracted (200–400 msec window).
Mindfulness Based Cognitive Therapy (MBCT)
The MBCT intervention for BD was developed from the 8-week MBCT program for major depression. Specifically, the 8-week MBCT intervention for BD included psycho-education with a specific focus on mania and the early warning signs of mania and depression. During their participation in the present study, participants were encouraged to continue with all of their outpatient appointments, medications and other services they were receiving. None of the participants reported using non-MBCT meditation or yoga for therapeutic purpose during their participation in the present study. The MBCT intervention was led by an experienced therapist with recognized expertise in the delivery of cognitive therapy and MBCT.
Statistical Analysis
Statistica 10 was used for the statistical analyses. Independent-sample t-tests were performed between control participants and individuals with bipolar disorder. Dependent-sample t-tests were performed between the individuals with bipolar prior and post their mindfulness based intervention. No further analyses were performed due to the pilot nature of these data. Data were reported as mean ± STDEV, significant values p < 0.05 and when refer to tendencies p < 0.1.
