Participants
Participants were recruited based on the inclusion criteria outlined below:
1) diagnosed with mild dementia or MCI, with a score of at least 20 points on the Mini-Mental State Examination (MMSE) (see “Assessment” below).
2) living within reasonable traveling distance of a hospital (i.e., within 30-60 minutes).
3) being able to perform homework assignments for at least 15 minutes every day.
4) being able to complete more than two-third of the program.
Individuals who met the following criteria were excluded:
1) concurrent psychiatric disorders (e.g., schizophrenia, bipolar disorder, substance-related disorders, and Cluster A personality disorders).
2) a history of epilepsy, with an electroencephalogram that has not been normalized.
3) cognitive dysfunction that precludes CBT.
4) physical health problems which made engagement in psychological treatment difficult.
5) current engagement in another structured psychological intervention.
6) inability or unwillingness to participate in the study because of other commitments, lack of motivation, difficulty in comprehending the program, or severe cognitive decline prior to commencement of the program.
7) hospitalization due to severe depression or anxiety, self-injury, or suicide attempt.
These criteria were not consistent with the CBT criteria adopted in previous dementia studies. [20,21] As this study was the first trial of the CBT program for dementia and MCI, setting more detailed criteria allowed us to conduct it with utmost care and caution.
Setting and Recruiting Procedure
This study was a single-arm, pre-post study (Figure 1) conducted between 2016 and 2018 (for approximately two years) at the psychiatry outpatient department in Nippon Medical School Hospital (the monthly average number of outpatients was approximately 2,300; of these, the proportion of patients with dementia or MCI was 3.69%). Due to the exploratory nature of the study, a convenience sampling approach was used. In previous studies, participants could receive the CBT sessions at their own homes,[21] but outreach psychological services are not yet available in Japan. Thus, we conducted the program at an outpatient department. Participants with MCI or dementia were referred to the doctors (i.e., psychiatrists and neurologists) in the research team. We also requested the patients’ caregivers to participate in this program. The study team approached the participants who showed initial interest in this study and provided them with relevant information (e.g., purpose, program content, potential benefits of participating, duration, time commitment per month, rewards, and round-trip travelling expenses) to ensure that they were fully informed prior to agreeing to participate.
[Insert Fig. 1 about here]
Ethical Approval
The Ethics Committee of Nippon Medical School Hospital (27-01-543) approved the design of this research and the publication of this paper prior to the commencement of the program. Participants were asked to provide written informed consent. The study protocol adhered to the ethical standards outlined in the Declaration of Helsinki (as revised in Brazil).[23] Participants could take part in this program without incurring any expense. In addition, round-trip travelling allowances for each session and rewards (3,000 yen) for each assessment (three assessments: pre-intervention, post-intervention, and the three-month follow-up) were provided to participants. The aforementioned study terms were explained to them prior to obtaining their informed consent.
Intervention
The CBT program for people with dementia or MCI, developed [22] by referring to previous studies, [20,21,24-26] was individualized with the aim of improving the mental health and QOL of participants. Clinical psychologists, psychiatrists, and neurologists who specialized in geriatrics discussed how the CBT sessions should be structured and developed an original manual for this program. Furthermore, we prepared case examples for inclusion in the manual based on our clinical experience with older Japanese people. Therefore, the development of the program did not require any further consideration of culturally relevant aspects.
The program consisted of eight sessions (Table 1) on topics such as psychoeducation, behavioral activation, relaxation training (deep breathing and progressive muscle relaxation), and cognitive restructuring. It also included two optional sessions (communication skills and problem-solving skills); however, none of the participants engaged in these during the trial. The two relaxation training sessions were developed with reference to a brief relaxation technique.[27] A brief workbook discussing the topics was provided to each participant at no charge. Reading a topic for the next session as homework was optional. A brief assessment of psychological distress was conducted at the beginning of each session and participants were asked to attempt the CBT skills learned in the sessions. Additionally, they were encouraged to make notes in the workbook. Although each session lasted for approximately 60 minutes once a week in a previous study on CBT for dementia, [20] we set our session duration to be between 30 and 40 minutes, which was conducted every two weeks to account for the participants’ loss of concentration and burden of hospital visit.
As previous studies recommended that CBT sessions for dementia include family caregivers, [20,21,25,28] we requested the participants’ caregivers to participate in each session. Regarding the number of CBT sessions, previous studies [20,21] conducted 10 to 23 sessions in their programs. However, since most Japanese individuals diagnosed with dementia or MCI were unfamiliar with the CBT and considering the burden on the participants who had to visit the implementation sites, we decided on a shorter, eight-session program.
[Insert Table 1 about here]
The program was delivered by a Japanese clinical psychologist (the therapist) who was familiar with CBT and had more than 10 years of training. Prior to this trial, we devised a fidelity checklist in Japanese containing the six most important components of each session: “all information covered,” “the participant successfully completed the task in the session,” “successfully encouraging participant to think of the material,” “successfully teach the material,” “successfully introduced the homework,” and “keeping the participant focused on the session.” The therapists recorded each session with each participant, and research members (clinical psychologists, neurologists, and psychiatrists) who were not directly involved in the sessions rated them on the fidelity checklist referring to the manual. The study team evaluated the sessions on the aforementioned criteria with scores ranging from 1 (not at all) to 5 (very well), and overall fidelity scores ranged from 6 (the lowest) to 30 (the highest). The therapist and the research members engaged in over ten hours of peer-to-peer training on the program protocol and held regular peer supervision sessions for ongoing cases. If the fidelity scores were low, the members discussed the reason and solution for the next sessions during the peer supervision. Furthermore, the therapist received on-demand clinical supervision by a member of the research team, a psychiatrist with over 30 years of clinical experience and over five years of CBT supervisory experience.
Measurements
Participants were interviewed three times at the hospital: prior to the commencement of the program (pre-intervention; week 0), immediately after the completion of the program (post-intervention; week 17), and three months thereafter. At each interview, participants completed the measuring instruments. We collected sociodemographic details of the participants and their caregivers such as age, sex, their interpersonal relationship, the participant’s diagnosis, level of education, job history, and basic living conditions. A well-trained study member who was not involved in presenting the program assessed the participants, except in the self-reported scales below, which they filled out individually.
Pre-intervention assessment measure
The Mini-International Neuropsychiatric Interview (MINI). The MINI (DSM-IV; ICD-10) [29] is a brief, structured interview that was used at the baseline assessment to evaluate the participants on the exclusion and inclusion criteria.
Post-intervention assessment measures
The Client Satisfaction Questionnaire (CSQ-8). The CSQ-8 is a self-reported, eight-item instrument measuring participants’ satisfaction with mental health services (quality of service, kind of service, whether needs were met, whether they would recommend the program to a friend, amount of help received, ability to deal with problems, overall satisfaction, and return needed).[30,31] Some sample items are: “To what extent did the program meet your needs?” and “How satisfied are you with the amount of help you have received?” The items are rated on a four-point scale, with total scores ranging from eight to 32; higher scores indicate greater satisfaction. The CSQ-8 has demonstrated good reliability (Cronbach’s alpha coefficient = .83).[31] We administered this questionnaire both to participants and their caregivers at the post-intervention assessment to evaluate the feasibility of the program.
Post-assessment reports. We asked participants and their caregivers about the program’s comprehensibility (i.e., “Do you understand the content of this program?”) and usefulness (i.e., “Do you think this program is useful for you?”). These questions were answered on a four-point scale: 0: Not at all, 1: A little, 2: Moderately, and 3: Very.
Three-period measures
Mini-Mental State Examination (MMSE). The MMSE is a brief measure of cognitive function used worldwide, with total scores ranging from 0 to 30.[32,33] The MMSE has been shown to be a valid test for cognitive function and has good test-retest reliability (= .89).[32] We used this instrument to evaluate the level of participants’ cognitive decline relative to the exclusion criteria for this study and to assess score changes across the three assessment periods.
Geriatric Depression Scale-15 (GDS-15). The GDS-15 is a 15-item, self-reported scale measuring depressive symptoms in older people, [34,35] with the questions requiring yes (1) or no (0) answers. The GDS-15 has good internal consistency (Cronbach’s alpha coefficient = .83) and clinical usefulness. [35,36] This scale was administered to the participants only.
Hospital Anxiety and Depression Scale-Anxiety (HADS-A). The HADS is a 14-item, self-reported scale measuring anxiety and depression [37,38] on a four-point scale ranging from 0 to 3. The scale has two subscales, anxiety (HADS-A) and depression (HADS-D), each containing seven items. HADS has good internal consistency (Cronbach’s alpha coefficient = .60 to .93) and construct validity. [39,40] We used the HADS-A for both participants and their caregivers because the Japanese version of the HADS-D reportedly has low internal consistency.[41]
Quality of Life-Alzheimer’s Disease Scale (QOL-AD). The QOL-AD is designed to measure QOL in older adults with cognitive impairment.[42] It contains 13 items measuring 13 domains (physical health, energy, mood, living conditions, memory, family, marriage [or a close relationship], friendship, self as a whole, ability to do chores, ability to do something fun, financial capabilities, and life as a whole) rated on a four-point scale. It has good internal reliability (Cronbach’s alpha coefficient = .82 to .84).[43] This instrument consists of two formats: a self-reported format completed by an older adult and an informant format completed by a caregiver. We used this scale for both the participants and their caregivers.
Kessler Psychological Distress Scale (K6). The K6 is a brief, self-reported scale to assess psychological distress and has good internal consistency (Cronbach’s alpha coefficient = .89) among adults.[44] It contains six items on a five-point scale ranging from 0 to 4. We used the K6 at each session to monitor the mental health condition of both the participants and their caregivers and to assess whether a CBT session had a detrimental effect on the participants’ conditions.
Neuropsychiatric Inventory Questionnaire (NPI-Q). The NPI-Q is a brief version of the NPI.[45] This questionnaire is a 12-item caregiver-informant scale intended for self-administration, measuring the severity of neuropsychiatric symptoms (NPI-Q) on a scale from 0 to 3, with total scores ranging from 0 to 36.[46] The NPI-Q has good test-retest reliability (= .80 to .94) and large inter-scale correlations with the NPI (= .71 to .93).[46] The Japanese version of the NPI-Q has demonstrated similar results, with adequate validity and reliability.[47] We administered this questionnaire to the caregivers to assess participants’ neuropsychiatric symptoms.
Patient Health Questionnaire-9 (PHQ-9). The PHQ-9 is a self-reported questionnaire measuring depressive symptoms. [48,49] It includes nine items rated on a four-point scale ranging from 0 to 3. The PHQ-9 has good internal consistency (Cronbach’s alpha coefficient = .86 to .89), construct validity, and clinical usefulness. [50,51] We administered this scale to the caregivers.
Japanese version of the Zarit Caregiver Burden Interview–short version (J-ZBI_8). The J-ZBI_8, the shortened version of the Zarit Caregiver Burden Interview, [52,53] is a self-reported instrument with eight items measuring subjective care burden. The J-ZBI_8 has demonstrated good reliability (Cronbach’s alpha coefficient = .89) and construct validity, comparable to the original version.[54] We administered this to the caregivers.
Statistical Analysis
In addition to examining the feasibility and acceptability of this program, we calculated descriptive statistics of all outcome variables and used a linear mixed model to compare the outcome scores evaluating the impact of this program. We included time as a fixed factor and participants as a random factor in our linear mixed model. Furthermore, we used the restricted maximum likelihood method and Cohen’s d to calculate the effect size. A significance level of p < 0.05 was adopted. We did not conduct pre-power analysis to calculate the sample size required to produce an effect because of the study’s small sample size. All statistical analyses were performed using IBM SPSS Statistics, version 22.