The study involved a group of 103 people with mood disorders, treated at the Department of Psychiatry of the Pomeranian Medical University in Szczecin. It was based on a survey performed using a questionnaire on sociodemographic and medical data, as well as standardized research tools. The research was conducted from December 2020 to January 2022. The inclusion criteria for the study were: age over 18 years, consent to participate in the study, clinically confirmed mood disorder (depression, bipolar affective disorder, mixed depressive and anxiety disorders), and completion of the entire set of questionnaires. Failure to meet at least one of the above conditions was a criterion for exclusion from the study. Since one respondent was excluded, a total of 102 questionnaire sets were eventually analyzed. The patients had been diagnosed with mental disorders by a physician, based on the tenth revision of the International Statistical Classification of Diseases and Related Health Problems (ICD-10), where each disease is assigned a code containing a letter and a number corresponding to its meaning. For bipolar affective disorder it is F31, for depressive disorder―F32, recurrent depressive disorder―F33, and mixed anxiety and depressive disorder―F41.2 (6). Paper copies of the questionnaires were distributed among patients of the Department of Psychiatry during hospitalization and outpatient visits. The respondents were informed that participation in the study was anonymous and voluntary, and that they could opt out at any stage. Informed consent was obtained from all subjects and/or their legal guardian(s). The completed questionnaires were placed in a box prepared for this purpose.
The author questionnaire consisted of two parts concerning sociodemographic data (age, sex, marital status, education, place of residence, employment status) and medical data (type of disorder, duration of the disease, medication time, number of medications used during the study period, attending medical appointments). The standardized research instruments were: the Adherence to Refills and Medication Scale (ARMS), the Acceptance of Illness Scale (AIS), the Beck Depression Inventory (BDI), and the Satisfaction with Life Scale (SWLS).
The Adherence to Refills and Medication Scale (ARMS), developed by Kripalani et al., is a 12-item questionnaire consisting of two subscales: the first eight questions concerns medication adherence, and the next four are about prescription adherence. Each answer is assigned a value: 1 = never, 2 = seldom, 3 = often, 4 = most of the time. The total score indicates the level of adherence—the lower the score, the better the adherence (27).
The Acceptance of Illness Scale (AIS) by B. Felton, T. Revenson, and G. Hinrichsen was adapted to Polish conditions by Z. Juczyński. It comprises eight statements, each rated on a five-point Likert scale (from 1―I fully agree, denoting poor adaptation to a disease to 5―I fully disagree, meaning its full acceptance). The total score is a sum of all points, and falls between 8 and 40. A low score reflects a lack of acceptance and poor adaptation to a disease, and high scores indicate a lack of negative emotions associated with the disease (28).
The Satisfaction with Life Scale (SWLS) by E. Diener, R.A. Emmons, R.J. Larson, and S. Griffin measures the level of life satisfaction. It includes five items assessed on a seven-point Likert scale (from 1―I strongly disagree to 7―I strongly agree). The final score can range from 5 to 35 points—the higher the score, the higher the life satisfaction. The results should be interpreted with reference to the sten norms: 1-4 sten―low score, 5-6 sten―average score, 7-10 sten―high score (29).
The Beck Depression Inventory (BDI) is one of the most widely used tools for assessing symptoms of depression (30, 31). The inventory contains 21 questions concerning sadness, the future, neglect, loss of pleasure in activities performed, feelings of guilt and punishment, the feeling of self-dislike, self-criticism, suicidal thoughts, tearfulness, nervousness, lack or loss of interests, indecisiveness, lower self-esteem, lack of energy, sleep rhythm, the feeling of fatigue, appetite, weight loss, and sexual interest (32). The questions refer to the last 30 days of life. Respondents can choose from four answer options with assigned values from 0 to 3 points, where 0 means no symptoms and 3 means significant severity. The higher the score, the more severe the depressive symptoms. The results are interpreted as follows: 0–11 points—no depressive symptoms, 12–26 points—mild symptoms, 27–49 points—moderate symptoms, 50–63 points—severe symptoms (31).
The study was approved by the Bioethics Committee of the Pomeranian Medical University in Szczecin (KB-0012/153/17).
Characteristics of the study sample
The study included 102 people with mood disorders. The study sample consisted of 91.18% women and 8.82% men, 64.71% of whom were in a relationship. Of the respondents, 57.84% had higher education, 14.71% had primary or vocational education, and 27.45% had secondary education. Some 21.57% were rural residents, 30.39% lived in a city with a population of up to 100,000, and 48.04% were from a city with a population of over 100,000. The majority of the participants (59.8%) were employed compared to 40.2% of those being out of work. The mean age was 42.26 years, and the median was 38.5 years. The most numerous patients were those aged 20-25 years (32.9%).
As many as 47.06% of the respondents suffered from depressive disorder, 34.31% had mixed (anxiety-depressive) disorder, 11.76%―bipolar disorder, and 6.86%―other disorders.
The duration of the disorder ranged from one year to 36 years, the average time was 9.31 years, while the median was seven years. The most numerous group was the one in which respondents had been ill for more than five years (more than 55%), 41.18% of the respondents had been ill for less than five years, and three people did not specify the duration of the disorder.
As for the time of taking medication, 85.29% of the participants took medication once a day in the morning, while 14.71% took medication at other times of the day. More than half of the respondents (53.92%) took two or three different drugs daily, 24.51% took one drug, and 21.57% took more than three drugs.
When it comes to medical appointments, 10.78% of people deliberately did not attend a pre-arranged appointment.
Statistical analysis
Quantitative and categorical variables (nominal and ordinal) were characterized using descriptive statistics methods. For quantitative variables, the following were determined: measures of central tendency (M―mean, Mdn―median), measures of variability (SD―standard deviation, IQR/2―interquartile range, CV―coefficient of variation). For categorical variables, we determined measures of structure: number (n) and frequency (%). The results of standardized psychometric measurements were calculated according to the rules described by their creators, and converted to a sten scale using norms for the Polish general population.
Classical statistics based on null hypothesis testing was used for statistical inference. The impact of selected medical variables and the severity of depressive symptoms on life satisfaction (the SWLS), adherence (the ARMS), and acceptance of the disease (the AIS) were analyzed using regression models. Multivariate linear regression models with least squares parameter estimation were tested. The multicollinearity of independent variables was checked by determining the tolerance coefficient to avoid model redundancy.
Categorical variables were coded using a sigma-constraint method (quasi-experimental). All predictors were entered into the model simultaneously. Stepwise progressive introduction of predictors was used to build a determinant model that would explain the variance of the dependent variable to the greatest extent. The degree of overall explained variance of the dependent variable was estimated by determining the adjusted R2 value. For each predictor, the unstandardized (b) and standardized (βstand.) regression coefficient was determined, along with the 95% confidence interval (95% CI).
A default level of statistical significance of 0.05 was assumed for all analyses. Calculations were performed using the Statistica software v. 13.3 (TIBCO Software Inc., Palo Alto, California, USA).