Abstract
Background
Knee osteoarthritis (KOA) is a major public health concern, particularly in Morocco. Its association with mental health, especially depressive symptoms, remains insufficiently documented in North African/Mediterranean populations. This study investigated the prevalence of depression and associated factors among patients with symptomatic KOA.
Methods
This cross-sectional observational study included patients with KOA diagnosed according to the American College of Rheumatology (ACR) criteria. Clinical and psychological assessments were performed using the Western Ontario and McMaster Universities Osteoarthritis Index (WOMAC) and the Hospital Anxiety and Depression Scale (HADS). Radiographic severity was assessed on available and interpretable knee radiographs using the Kellgren–Lawrence (KL) grading system. Clinically significant depression was defined as HADS-D ≥ 11. Multivariable logistic regression (restricted to participants with available radiographs) was used to identify factors independently associated with depression.
Results
A total of 410 patients were included; 61.9% were women, with a mean age of 61.8 ± 9.5 years and a mean body mass index (BMI) of 28.1 ± 4.4 kg/m². Depression (HADS-D ≥ 11) was observed in 130 patients (31.7%), of whom 72.3% were women. Multivariable analysis (n = 280, participants with available radiographs) identified factors independently associated with depression: female sex (aOR = 1.45; 95% CI 1.10–2.10; p = 0.010), higher BMI (aOR = 1.06; 95% CI 1.03–1.09; p < 0.001), higher WOMAC pain score (aOR = 1.04; 95% CI 1.02–1.06; p < 0.001), greater functional limitation (WOMAC function score) (aOR = 1.01; 95% CI 1.01–1.02; p = 0.002), presence of comorbidities (aOR = 1.40; 95% CI 1.15–1.75; p = 0.004), and physical inactivity (aOR = 1.25; 95% CI 1.05–1.60; p = 0.020). In contrast, KL grade was not significantly associated with depression (aOR = 1.02; 95% CI 0.98–1.06; p = 0.32).
Conclusion
Nearly one-third of patients with symptomatic KOA had clinically significant depressive symptoms, with a higher proportion among women. Depression was associated with both non-modifiable (female sex) and potentially modifiable factors, including BMI, pain severity, functional limitation, comorbidities, and physical inactivity. The absence of a significant association between KL grade and depression supports a comprehensive management approach that addresses pain, physical activity, and mental health.
Keywords: Knee osteoarthritis, Depression, Associated factors, Pain, Functional limitation, Multidisciplinary management.
Introduction
Scientific background and rationale
Knee osteoarthritis (KOA) is a chronic, degenerative, and multifactorial joint disease that affects nearly 22% of individuals over the age of 40 worldwide [1]. It is characterized by progressive cartilage degradation, leading to pain, stiffness, and functional limitations that may result in long-term disability [2]. Beyond joint symptoms, KOA is frequently accompanied by comorbid conditions, including mental health disorders particularly depression which are increasingly recognized as clinically relevant in this population. A systematic review reported a pooled prevalence of depression of approximately 30% among patients aged 45 to 75 years with knee osteoarthritis, with variability across studied populations [3–5]. The chronic pain depression relationship may create a vicious cycle: pain can exacerbate depressive symptoms, while depression may increase pain perception and reduce adherence to treatment [6, 7]. Despite this bidirectional association, routine depression screening remains limited in osteoarthritis care, particularly in middle-income countries such as Morocco [8, 9]. Furthermore, most available evidence originates from Western settings, with fewer data from North African populations, where cultural and socioeconomic factors may influence symptom expression, health behaviors, and access to mental health care.
Identifying factors associated with depression in KOA is therefore essential for implementing comprehensive and context-adapted management strategies. Several correlates have been reported, including female sex, elevated body mass index (BMI), cardiometabolic comorbidities (e.g., diabetes and hypertension), low physical activity, and greater pain severity [10, 11]. However, the relative contribution of these factors in non-Western populations remains insufficiently explored.
Context specific to North African populations
The prevalence and clinical characteristics of depression among patients with symptomatic KOA are poorly documented in North African settings. Most studies have been conducted in European, North American, or Asian cohorts, which may limit the generalizability of findings to other sociocultural and healthcare contexts [12]. The North African region has distinct demographic and health-system characteristics that may affect both the expression and the management of depression in osteoarthritis [13, 14]. Disparities in access to care, varying levels of education, and cultural perceptions of chronic illness and mental health may influence both depressive symptom reporting and its functional impact [15].
Studies from the Maghreb have reported a high burden of depressive disorders in populations living with chronic diseases, with clinical presentations that may differ from those observed elsewhere [16]. In this context, identifying locally relevant factors associated with depression in KOA could inform tailored care pathways and psychosocial interventions. Our study, conducted in a North African cohort of patients with symptomatic KOA, aims to contribute new evidence to better characterize these interactions and support integrated care approaches.
Study objectives
The primary objective of this study was to estimate the prevalence of depression and identify factors associated with depression among North African patients with symptomatic KOA managed in a Moroccan tertiary care hospital.
Secondary objectives were:
To analyze the relationship between pain severity and functional limitations (assessed using the WOMAC score) and depressive symptoms (assessed using the HADS-Depression subscale);
To evaluate the influence of body mass index (BMI), comorbidities, and physical activity level on the risk of depression.
Hypothesis
Depression is associated with higher pain and functional impairment, the presence of comorbidities, and reduced physical activity among patients with knee osteoarthritis.
Methods
Study design
This was a cross-sectional, descriptive, and analytical observational study designed to identify factors associated with depression among patients with symptomatic knee osteoarthritis (KOA). The study was conducted in the Rheumatology Department of the Mohammed V Military Teaching Hospital (HMIMV) in Rabat, a national referral center serving both civilian and military populations.
Setting, location, and study period
The study was carried out over 12 months (January to December 2023). Patients were recruited consecutively among outpatients presenting with chronic knee pain during scheduled rheumatology consultations. Data were collected through face-to-face interviews using standardized questionnaires administered by trained physicians. All participants received detailed information about the study and provided written informed consent prior to inclusion. The study protocol was approved by the HMIMV Institutional Ethics Committee.
Participants
Inclusion criteria were age ≥ 18 years and symptomatic KOA meeting the American College of Rheumatology (ACR) clinical classification criteria. Standard weight-bearing anteroposterior knee radiographs were obtained when available and interpretable; radiographic KOA was defined as a Kellgren–Lawrence (KL) grade ≥ 2 and was used for radiographic severity analyses. Exclusion criteria were inflammatory rheumatic diseases (e.g., rheumatoid arthritis, spondyloarthritis), post-traumatic or crystal-induced osteoarthritis, current antidepressant treatment, an active psychiatric disorder requiring specialized care at the time of inclusion, or refusal to participate.
Eligibility was confirmed by a rheumatologist with more than five years of clinical experience. The patient selection process is detailed in Fig. 1.
Fig. 1.
Flowchart of study participants. Flow diagram showing patient selection and inclusion. A total of 430 patients with symptomatic knee osteoarthritis were assessed for eligibility between January and December 2023. Twenty patients were excluded (n=6: active psychiatric disorder or current antidepressant treatment; n=8: refusal; n=6: incomplete data). The final analysis included 410 participants, classified as depressed (HADS-D ≥11; n=130) or non-depressed (HADS-D <11; n=280). Abbreviations: ACR, American College of Rheumatology; aOR, adjusted odds ratio; BMI, body mass index; CI, confidence interval; HADS, Hospital Anxiety and Depression Scale; HADS-D, Hospital Anxiety and Depression Scale—Depression subscale; IQR, interquartile range; KL, Kellgren–Lawrence; KOA, knee osteoarthritis; NSAIDs, non-steroidal anti-inflammatory drugs; SD, standard deviation; WHO, World Health Organization; WOMAC, Western Ontario and McMaster Universities Osteoarthritis Index
Sampling strategy
Participants were enrolled consecutively as they attended outpatient consultations. No random sampling or randomization was performed; all eligible patients meeting inclusion criteria were included.
Study variables
Outcome
The primary outcome was clinically significant depressive symptoms, defined as a score ≥ 11 on the depression subscale of the Hospital Anxiety and Depression Scale (HADS-D). Participants were classified as depressed (HADS-D ≥ 11) or non-depressed (HADS-D < 11).
Explanatory variables
Sociodemographic and clinical variables were defined as follows:
Sex: male or female (self-reported).
Age: recorded in years as a continuous variable.
Body mass index (BMI): calculated as weight (kg) divided by height squared (m²), treated as a continuous variable. For descriptive analyses, BMI was also categorized according to WHO thresholds (normal < 25; overweight 25–29.9; obesity ≥ 30 kg/m²).
Pain severity: assessed using the WOMAC pain subscale (range 0–20), with higher scores indicating greater pain.
Functional limitation (disability): assessed using the WOMAC function subscale (range 0–68), with higher scores indicating greater disability.
Joint stiffness: assessed using the WOMAC stiffness subscale (range 0–8).
Physical inactivity: defined according to WHO recommendations as < 150 min/week of moderate-to-vigorous physical activity; participants meeting ≥ 150 min/week were classified as physically active.
Comorbidities were recorded as binary variables (yes/no) based on patient self-report and/or available medical records when applicable. These included hypertension, type 2 diabetes, dyslipidemia, and cardiovascular disease. For regression analyses, comorbidity burden was also summarized using a composite variable indicating the presence of at least one comorbidity (yes/no).
Radiographic severity: assessed on available standard weight-bearing anteroposterior knee radiographs using the Kellgren–Lawrence (KL) grading system. Analyses involving KL grade were restricted to participants with available and interpretable radiographs. For radiographic analyses, we focused on participants with radiographic KOA (KL ≥ 2) and grouped grades as KL 2 versus KL 3–4 when needed. KL grade was analyzed as an ordinal variable in regression models.
Additional clinical history variables
Past history of major depressive episode: recorded based on patient self-report and/or available medical records when applicable. This variable referred to a previous episode and did not contradict the exclusion of current antidepressant treatment or active psychiatric disorders requiring specialized care at the time of inclusion (exclusion criteria).
Potential confounders
Potential confounders considered a priori included education level, symptom duration (months), and sleep disturbances (e.g., chronic insomnia), when available. Variables included in the final multivariable model were selected based on clinical relevance and completeness of data across participants with available radiographs.
Data sources and measurement tools
Data were collected using a structured questionnaire including sociodemographic and clinical characteristics (age, sex, medical history, weight, height, BMI), HADS, and WOMAC. Physical activity was assessed according to WHO criteria (≥ 150 min/week considered regular; <150 min/week considered insufficient). Comorbidities were recorded based on medical history and/or ongoing treatment. Radiographic severity was graded using the Kellgren–Lawrence classification on standard weight-bearing anteroposterior knee radiographs when available and interpretable.
All questionnaires were completed in the presence of the investigator to ensure standardization and minimize missing data.
Bias management
Several measures were implemented to minimize bias: consecutive recruitment to reduce selection bias, training of physicians in standardized data collection, double data entry to limit transcription errors, and multivariable analysis to adjust for relevant confounders identified in the literature.
Sample size
Sample size was calculated using the Schwartz formula for cross-sectional studies. Assuming an estimated depression prevalence of 30%, a 5% margin of error, and a 95% confidence level (Z = 1.96), a minimum of 323 participants was required. To account for exclusions and missing data, 410 participants were included.
Quantitative variable handling
Continuous variables (e.g., age, BMI, WOMAC scores) were summarized as mean ± standard deviation. Where clinically relevant, BMI ≥ 30 kg/m² defined obesity. For analyses, WOMAC pain and WOMAC function were handled as continuous variables.
Statistical analysis
Categorical variables were described as frequencies and percentages, and continuous variables as mean ± standard deviation. Group comparisons were performed using the chi-square test for categorical variables and Student’s t-test for continuous variables. Binary logistic regression was used to identify factors independently associated with depression, with results reported as adjusted odds ratios (aORs) and 95% confidence intervals (95% CIs). Missing data were handled using mean imputation for continuous variables and complete-case analysis for categorical variables. Analyses involving Kellgren–Lawrence (KL) grade were restricted to participants with available and interpretable knee radiographs. A sex-stratified analysis was performed to explore the association between radiographic severity (KL 2 vs. KL 3–4) and depression. Statistical analyses were performed using jamovi software (version 2.26.6).
Results
Participants
Figure 1 presents the participant selection flow diagram. Between January and December 2023, 430 patients with symptomatic knee osteoarthritis were assessed for eligibility. Twenty patients were excluded (n = 6 due to an active psychiatric disorder or current antidepressant treatment, n = 8 due to refusal to participate, and n = 6 due to incomplete data). In total, 410 participants were included in the final analysis and classified into two groups: depressed (HADS-D ≥ 11; n = 130) and non-depressed (HADS-D < 11; n = 280).
Descriptive data
The study population included 254 women (61.9%) and 156 men (38.1%), with a mean age of 61.8 ± 9.5 years. The mean body mass index (BMI) was 28.1 ± 4.4 kg/m².
In the depressed group (n = 130), 72.3% were women (n = 94), compared with 57.1% (n = 160) in the non-depressed group (p = 0.004). Mean BMI was higher in the depressed group (29.7 ± 4.8 kg/m²) than in the non-depressed group (27.4 ± 3.9 kg/m²; p < 0.001). Mean symptom duration was 26 ± 7 months in the depressed group versus 23 ± 8 months in the non-depressed group (p = 0.010). These characteristics are detailed in Table 1.
Table 1.
Baseline characteristics according to depressive status (n = 410) Legend: baseline sociodemographic and clinical characteristics of patients with symptomatic KOA, stratified by depressive status (HADS-D ≥ 11 vs. HADS-D < 11). Continuous variables are presented as mean ± SD and categorical variables as n (%). P-values were obtained using student’s t-test (continuous variables) or χ² test (categorical variables)
| Characteristic | Total (n = 410) | Depressed (HADS-D ≥ 11) (n = 130) | Non-depressed (HADS-D < 11) (n = 280) | p-value |
|---|---|---|---|---|
| Age (years), mean ± SD | 61.8 ± 9.5 | 62.4 ± 9.1 | 61.5 ± 9.7 | 0.37 |
| Female sex, n (%) | 254 (61.9) | 94 (72.3) | 160 (57.1) | 0.004 |
| BMI (kg/m²), mean ± SD | 28.1 ± 4.4 | 29.7 ± 4.8 | 27.4 ± 3.9 | < 0.001 |
| Obesity (BMI ≥ 30 kg/m²), n (%) | 122 (29.8) | 56 (43.1) | 66 (23.6) | < 0.001 |
| Symptom duration (months), mean ± SD | 24 ± 8 | 26 ± 7 | 23 ± 8 | 0.010 |
| Education: primary or less, n (%) | 248 (60.5) | 94 (72.3) | 154 (55.0) | 0.001 |
| Education: secondary or higher, n (%) | 162 (39.5) | 36 (27.7) | 126 (45.0) | — |
| Employment: employed, n (%) | 210 (51.2) | 48 (36.9) | 162 (57.9) | < 0.001 |
| Employment: retired/inactive, n (%) | 200 (48.8) | 82 (63.1) | 118 (42.1) | — |
| Monthly income (€, median [IQR]) | 500 [200–800] | 250 [100–500] | 600 [300–900] | 0.002 |
| Public health insurance, n (%) | 298 (72.7) | 110 (84.6) | 188 (67.1) | 0.011 |
| Private health insurance, n (%) | 112 (27.3) | 20 (15.4) | 92 (32.9) | — |
Abbreviations: BMI body mass index, HADS-D Hospital Anxiety and Depression Scale—Depression subscale, IQR interquartile range, SD standard deviation
Clinical data and comorbidities
WOMAC scores were significantly higher in depressed patients than in non-depressed patients, including pain (13.6 ± 3.1 vs. 10.2 ± 2.9; p < 0.001), stiffness (5.1 ± 1.6 vs. 3.8 ± 1.7; p < 0.001), and functional limitation (41.8 ± 9.5 vs. 36.1 ± 10.2; p < 0.001) (Table 2).
Table 2.
WOMAC scores according to depressive status (n = 410) Legend: comparison of WOMAC subscales and total score between depressed and non-depressed patients. Data are shown as mean ± SD and median [IQR]. P-values were obtained using student’s t-test for mean comparisons
| WOMAC domain | Total (n = 410) | Depressed (n = 130) | Non-depressed (n = 280) | p-value |
|---|---|---|---|---|
| Pain (0–20), mean ± SD | 11.3 ± 3.5 | 13.6 ± 3.1 | 10.2 ± 2.9 | < 0.001 |
| Pain (0–20), median [IQR] | 11 [8–14] | 14 [11–16] | 10 [8–12] | — |
| Stiffness (0–8), mean ± SD | 4.2 ± 1.8 | 5.1 ± 1.6 | 3.8 ± 1.7 | < 0.001 |
| Stiffness (0–8), median [IQR] | 4 [3–5] | 5 [4–6] | 4 [2–5] | — |
| Function (0–68), mean ± SD | 38.1 ± 10.4 | 41.8 ± 9.5 | 36.1 ± 10.2 | < 0.001 |
| Function (0–68), median [IQR] | 38 [30–46] | 42 [35–49] | 36 [28–43] | — |
| Total (0–96), mean ± SD | 53.6 ± 14.2 | 60.5 ± 12.3 | 50.1 ± 13.6 | < 0.001 |
| Total (0–96), median [IQR] | 54 [43–64] | 61 [52–69] | 50 [40–59] | — |
Abbreviations: IQR interquartile range, SD standard deviation, WOMAC Western Ontario and McMaster Universities Osteoarthritis Index
Regarding comorbidities, hypertension was more frequent in the depressed group (46.2%) than in the non-depressed group (35.7%; p = 0.038). Cardiovascular disease was reported in 18.5% of depressed patients compared with 8.9% of non-depressed patients (p = 0.009). Multisite osteoarthritis was more prevalent among depressed patients (24.6%) than among non-depressed patients (12.9%; p = 0.003). A history of major depression was more frequently reported in the depressed group (32.3% vs. 5.7%; p < 0.001). Sleep disorders, particularly chronic insomnia, were also more frequent in depressed patients (47.7% vs. 17.9%; p < 0.001), as detailed in Table 3.
Table 3.
Comorbidities and clinical history according to depressive status (n = 410) Legend: distribution of comorbidities and clinical history stratified by depressive status (HADS-D ≥ 11 vs. HADS-D < 11). Values are n (%). P-values were obtained using χ² tests
| Variable | Total (n = 410) | Depressed (n = 130) | Non-depressed (n = 280) | p-value |
|---|---|---|---|---|
| Hypertension, n (%) | 160 (39.0) | 60 (46.2) | 100 (35.7) | 0.038 |
| Type 2 diabetes, n (%) | 92 (22.4) | 36 (27.7) | 56 (20.0) | 0.085 |
| Dyslipidemia, n (%) | 104 (25.4) | 40 (30.8) | 64 (22.9) | 0.072 |
| Cardiovascular disease, n (%) | 49 (12.0) | 24 (18.5) | 25 (8.9) | 0.009 |
| Multisite osteoarthritis, n (%) | 68 (16.6) | 32 (24.6) | 36 (12.9) | 0.003 |
| Past history of major depressive episode, n (%) | 58 (14.1) | 42 (32.3) | 16 (5.7) | < 0.001 |
| Chronic insomnia, n (%) | 112 (27.3) | 62 (47.7) | 50 (17.9) | < 0.001 |
Abbreviations: HADS-D Hospital Anxiety and Depression Scale - Depression subscale
Multivariable analysis of factors associated with depression
Multivariable logistic regression was performed among participants with available and interpretable knee radiographs (n = 280), allowing inclusion of radiographic severity (KL grade) in the adjusted model (Table 4). The model adjusted for age, sex, education level, BMI, cardiometabolic comorbidities, pain severity, functional limitation, and physical activity, and identified several independent associations with depression. Female sex was associated with higher odds of depression (aOR = 1.45; 95% CI 1.10–2.10; p = 0.010). Higher BMI was associated with depression (aOR = 1.06 per unit increase; 95% CI 1.03–1.09; p < 0.001). Each additional point on the WOMAC pain score was associated with higher odds of depression (aOR = 1.04; 95% CI 1.02–1.06; p < 0.001), and greater functional limitation was also associated (aOR = 1.01 per point; 95% CI 1.01–1.02; p = 0.002). Having at least one comorbidity was associated with depression (aOR = 1.40; 95% CI 1.15–1.75; p = 0.004), as was physical inactivity (aOR = 1.25; 95% CI 1.05–1.60; p = 0.020). Radiographic severity assessed using the Kellgren–Lawrence grade was not significantly associated with depression (aOR = 1.02; 95% CI 0.98–1.06; p = 0.32). These results are shown in Table 4.
Table 4.
Multivariable logistic regression for depression (HADS-D ≥ 11) Legend: adjusted odds ratios (aORs) from multivariable logistic regression identifying factors independently associated with depression (HADS-D ≥ 11). Analysis performed among participants with available and interpretable knee radiographs (n = 280). Continuous predictors are expressed per one-unit increase, unless stated otherwise
| ASSOCIATED FACTOR | aOR (95% CI) | p-value |
|---|---|---|
| Female sex | 1.45 (1.10–2.10) | 0.010 |
| BMI (per 1 kg/m²) | 1.06 (1.03–1.09) | < 0.001 |
| WOMAC pain (per 1 point) | 1.04 (1.02–1.06) | < 0.001 |
| WOMAC function (per 1 point) | 1.01 (1.01–1.02) | 0.002 |
| ≥ 1 comorbidity* | 1.40 (1.15–1.75) | 0.004 |
| Physical inactivity† | 1.25 (1.05–1.60) | 0.020 |
| KL grade (per 1 grade increase) | 1.02 (0.98–1.06) | 0.32 |
Abbreviations: aOR adjusted odds ratio, BMI body mass index, CI confidence interval, HADS-D Hospital Anxiety and Depression Scale Depression subscale, KL Kellgren–Lawrence, WOMAC Western Ontario and McMaster Universities Osteoarthritis Index
* Comorbidities: composite variable indicating the presence of ≥ 1 cardiometabolic comorbidity (hypertension, type 2 diabetes, dyslipidemia, and/or cardiovascular disease)
† Physical inactivity: <150 min/week of moderate-to-vigorous activity (WHO definition)
A sex-stratified analysis suggested a difference in depression according to radiographic severity in women (KL grade 2 vs. KL grades 3–4, p = 0.03), whereas no significant association was observed among men (p = 0.21) (Table 5).
Table 5.
Sex-stratified analysis of radiographic severity and depression Legend: analysis performed among participants with available and interpretable knee radiographs (Women n = 178; men n = 102). Radiographic severity was assessed using the Kellgren–Lawrence (KL) grading system and categorized as KL 2 versus KL 3–4. Depression was defined as HADS-D ≥ 11. Correlations are pearson’s r. P-values for correlation rows correspond to between-sex comparisons of correlation coefficients (Fisher r-to-z transformation)
| Parameter | Women (n = 178) | Men (n = 102) | p-value |
|---|---|---|---|
| KL grade 2, n (%) | 72 (40.4) | 44 (43.1) | 0.82 |
| KL grades 3–4, n (%) | 106 (59.6) | 58 (56.9) | |
| Depression (HADS-D ≥ 11), KL 2, n/N (%) | 32/72 (44.4) | 8/44 (18.2) | |
| Depression (HADS-D ≥ 11), KL 3–4, n/N (%) | 62/106 (58.5) | 28/58 (48.3) | |
| Correlation KL–WOMAC pain (r) | 0.35** | 0.18* | 0.04* |
| Correlation KL–WOMAC function (r) | 0.38** | 0.22* | 0.02* |
| Correlation KL–HADS-D (r) | 0.12 | −0.01 | 0.21 |
Abbreviations: HADS-D Hospital Anxiety and Depression Scale—Depression subscale, KL Kellgren–Lawrence, WOMAC Western Ontario and McMaster Universities Osteoarthritis Index. , p < 0.05; ** p < 0.01
Therapeutic management
Regarding treatment strategies, 73.2% of patients were receiving analgesics (paracetamol or mild opioids), 62.9% were using nonsteroidal anti-inflammatory drugs (NSAIDs), and 20.0% had undergone intra-articular injections. Moreover, 36.5% participated in therapeutic education programs including weight management strategies, and 24.9% were undergoing physiotherapy. Only 10.8% of patients were receiving psychological care despite the high prevalence of depressive symptoms. Surgical intervention was performed in 4.9% of cases. These data are summarized in Table 6.
Table 6.
Treatment strategies in patients with KOA (n = 410) Legend: therapeutic approaches used in the management of KOA in the study population. Categories are not mutually exclusive (a patient May receive more than one treatment)
| Treatment | n | % |
|---|---|---|
| Analgesics (paracetamol, mild opioids) | 300 | 73.2 |
| NSAIDs | 258 | 62.90 |
| Intra-articular injections | 82 | 20.00 |
| Weight loss and therapeutic education | 150 | 36.50 |
| Physiotherapy | 102 | 24.87 |
| Psychological care | 44 | 10.8 |
| Surgery | 20 | 4.87 |
Abbreviations: NSAIDs non-steroidal anti-inflammatory drugs, KOA knee osteoarthritis
Discussion
Key findings
In this cross-sectional study of patients with symptomatic knee osteoarthritis, depressive symptoms were frequent and consistent with prevalence ranges reported in the international literature [17]. This finding supports the relevance of routinely considering mental health in the clinical assessment of knee osteoarthritis.
In multivariable analysis, depressive symptoms were statistically independently associated with female sex and higher body mass index, in line with prior evidence showing a higher burden of depression among women and among individuals with excess weight [18–20]. Depressive symptoms were also associated with greater pain and functional limitation, which is clinically plausible given the close and potentially bidirectional relationship between chronic pain, disability, and psychological distress [21]. In addition, cardiometabolic comorbidities and physical inactivity were associated with depressive symptoms, reinforcing the importance of a multidimensional approach to osteoarthritis management that addresses both physical and psychological factors [22].
Radiographic severity assessed using the Kellgren–Lawrence grade was not independently associated with depressive symptoms. This may indicate that symptom burden and perceived functional impact are more closely related to psychological distress than radiographic changes alone, consistent with evidence on clinical–radiographic discordance in knee osteoarthritis [23, 24]. The sex-stratified analysis should be interpreted cautiously given its subgroup nature and the availability of radiographic data for only a subset of participants.
Interpretation and comparison with existing literature
Overall, our findings emphasize the close relationship between KOA symptom severity, functional limitation, and depressive symptoms. The observed associations likely reflect a complex, potentially bidirectional interplay between pain, disability, health behaviors (physical inactivity), and mental health, as described in prior work [25, 26]. The association between higher BMI and depressive symptoms may involve inflammatory pathways and the psychosocial burden of excess weight [27]. Similarly, the association with physical inactivity supports integrated strategies combining pain control, tailored exercise programs, and psychological support to improve both functional and mental health outcomes [28, 29].
An important clinical observation is the low rate of psychological care (10.8%) despite frequent depressive symptoms, suggesting barriers to mental health access such as limited availability of services, stigma, and the absence of routine screening protocols. This gap has also been reported in other settings and argues for patient-centered multidisciplinary care pathways [30].
Clinical implications
Given the high prevalence of depressive symptoms, routine screening using brief validated tools (e.g., HADS-D) could be considered during KOA consultations to facilitate early identification and referral when needed. Multidisciplinary models integrating rheumatology care with physiotherapy and mental health support may help address pain, disability, inactivity, and psychological distress simultaneously. Importantly, these recommendations should be viewed as pragmatic approaches aligned with the observed associations rather than as evidence of causal effects in this cross-sectional design.
Strengths and limitations
This study has several strengths, including a relatively large sample size and the use of widely validated instruments (WOMAC and HADS). However, several limitations must be acknowledged. First, the cross-sectional design precludes causal inference; depression may contribute to pain and disability and may also result from chronic symptoms. Second, WOMAC and HADS are questionnaire-based measures and may be subject to reporting bias. In addition, depressive symptoms were assessed using the HADS-D screening scale rather than a structured clinical psychiatric interview; therefore, misclassification is possible. Third, recruitment from a single tertiary center may limit external validity by overrepresenting patients with greater symptom severity or better access to specialized care. Fourth, some psychosocial determinants (e.g., social support, stress, detailed psychiatric history, and socioeconomic variables beyond those captured) were not comprehensively assessed and may have confounded some associations, and residual confounding cannot be excluded. Finally, radiographic data were available only for a subset of participants, and multivariable analyses including KL grade were restricted to those with available and interpretable radiographs (n = 280), which may have introduced selection bias and should be interpreted with caution.
Generalizability and future research
Although derived from a single Moroccan tertiary center, these findings may be relevant to similar populations in middle-income countries where KOA, obesity, and limited mental health resources coexist. Multicenter studies are needed to confirm these results across diverse settings and to better characterize cultural and health-system factors influencing depression in KOA. Longitudinal studies would help clarify temporal relationships, and interventional trials could evaluate whether integrated strategies (exercise programs, weight management, and psychological interventions) improve both depressive symptoms and KOA outcomes.
Conclusion
In this Moroccan cohort of patients with symptomatic KOA, nearly one-third had clinically significant depressive symptoms. Depression was associated with female sex and several potentially modifiable factors, including BMI, pain severity, functional limitation, comorbidities, and physical inactivity. Despite this burden, psychological care was infrequently used. These findings support the consideration of routine screening and integrated care approaches addressing both musculoskeletal symptoms and mental health.
What is already known on this subject
Depression is common among patients with knee osteoarthritis and negatively impacts quality of life and daily functioning.
Reported risk factors include female sex, high body mass index, severe pain, and comorbidities.
Despite these known associations, access to psychological support remains insufficient in routine care.
What this study adds
This study reports a high prevalence of depression among patients with symptomatic knee osteoarthritis in a North African context.
It highlights the major influence of modifiable factors (high BMI, pain, comorbidities, and physical inactivity).
Radiographic severity was not significantly associated with depression, underscoring the importance of symptoms and patient-perceived burden rather than radiological findings alone.
Psychological support was infrequently used despite frequent depressive symptoms, supporting systematic depression screening during consultations.
Acknowledgements
The authors warmly thank the paramedical staff of the Rheumatology Department at the Mohammed V Military Training Hospital in Rabat for their valuable assistance in data collection and patient follow-up. The authors express their gratitude to the Hospital Pharmacy Department for facilitating access to prescription data, as well as to the radiology teams for providing imaging and their participation in the centralized assessment of structural lesions.
Abbreviations
- ACR
American College of Rheumatology
- aOR
adjusted odds ratio
- BMI
body mass index
- CI
confidence interval
- HADS
Hospital Anxiety and Depression Scale
- HADS-D
Hospital Anxiety and Depression Scale—Depression subscale
- IQR
interquartile range
- KL
Kellgren–Lawrence
- KOA
knee osteoarthritis
- NSAIDs
non-steroidal anti-inflammatory drugs
- SD
standard deviation
- WHO
World Health Organization
- WOMAC
Western Ontario and McMaster Universities Osteoarthritis Index
Authors’ contributions
All authors meet the authorship criteria defined by the International Committee of Medical Journal Editors (ICMJE).- **Dr. Mahamadou Sagara: ** study conception, protocol development, data collection and analysis, initial manuscript drafting, final approval.- **Prof. Abderrahim Majjad: ** methodological supervision, critical revision for scientific content, validation of statistical analyses, final approval.- **Dr. Laila Taoubane: ** management of therapeutic data, comorbidity analysis, participation in manuscript writing, final approval.- **Prof. Ahmed Bezza: ** overall project supervision, contribution to the discussion, final proofreading, and approval for submission.All authors read and approved the final version of the manuscript and take responsibility for its content.
Funding
This study did not receive any specific funding from public or private organizations. No funding body played any role in the study design, data collection, analysis, interpretation, or manuscript writing. The study relied on internal resources of the hospital center and was conducted as part of routine clinical research activities.
Data availability
The datasets generated and/or analyzed during the current study are not publicly available due to institutional and confidentiality restrictions (data from a military hospital). However, they may be made available from the corresponding author upon reasonable request, subject to appropriate institutional/ethics committee authorization, where applicable.
Declarations
Ethics approval and consent to participate
This study was approved by the Ethics Committee of the Mohammed V Military Training Hospital in Rabat (Morocco). All participants provided informed consent in accordance with the Declaration of Helsinki. The official reference number is available upon reasonable request.
Consent for publication
Not applicable. No identifiable images or personal or clinical details that could identify participants are presented in this manuscript.
Competing interests
The authors declare no competing interests.
Footnotes
Publisher’s note
Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.
References
- 1.Cui A, Li H, Wang D, Zhong J, Chen Y, Lu H. Global, regional prevalence, incidence and risk factors of knee osteoarthritis in population-based studies. EClinicalMedicine. 2020;29–30100587. 10.1016/j.eclinm.2020.100587. [DOI] [PMC free article] [PubMed]
- 2.Neogi T. The epidemiology and impact of pain in osteoarthritis. Osteoarthritis Cartilage. 2013;21(9):1145–53. 10.1016/j.joca.2013.03.018. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 3.del Merry BM, Shukla SR, Oduoye MO, Nsengiyumva M, Tesfaye TM, Glinkowski WM. Prevalence of mental health disorders in knee osteoarthritis patients: a systematic review and meta-analysis. Ann Med Surg. 2024;86(8):4705–13. 10.1097/MS9.0000000000002258. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 4.Feng Q, Weng M, Yang Y, Zhan M. Anxiety and depression prevalence and associated factors in patients with knee osteoarthritis. Front Psychiatry. 2024;15:1483570. 10.3389/fpsyt.2024.1483570. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 5.Rathbun AM, Shardell MD, Ryan AS, Yau MS, Gallo JJ, Schuler MS, Stuart EA, Hochberg MC. Association between disease progression and depression onset in persons with radiographic knee osteoarthritis. Rheumatology (Oxford). 2020;59(11):3390–9. 10.1093/rheumatology/keaa141. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 6.Witkop ML, Lambing A, Nichols CD, Munn JE, Anderson TL, Tortella BJ. Interrelationship between depression, anxiety, pain, and treatment adherence in hemophilia: results from a US cross-sectional survey. Patient Prefer Adherence. 2019;13:1577–87. 10.2147/PPA.S212723. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 7.Bair MJ, Robinson RL, Katon W, Kroenke K. Depression and pain comorbidity: a literature review. Arch Intern Med. 2003;163(20):2433–45. 10.1001/archinte.163.20.2433. [DOI] [PubMed] [Google Scholar]
- 8.El-Ammari A, El Malki H, Moutawakkil SG, El Hilaly J, El Houari F, El Gnaoui S, Ragala MEA, El Rhazi K, Zarrouq B. Validation of the center for epidemiologic studies depression scale (CES-D) in a Moroccan sample with substance use disorder. BMC Psychiatry. 2023;23(1):723. 10.1186/s12888-023-05245-2. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 9.Cristóbal-Narváez P, Haro JM, Koyanagi A. Perceived stress and depression in 45 low- and middle-income countries. J Affect Disord. 2020;274:799–805. 10.1016/j.jad.2020.04.020. [DOI] [PubMed] [Google Scholar]
- 10.Idrissi Ouali O, El Mezouar I, Maiouak M, Akasbi N, Harzy T. Les comorbidités Au cours de La gonarthrose. Rev Rhum. 2023;90(S1):A253. 10.1016/j.rhum.2023.10.381. [Google Scholar]
- 11.Wieczorek M, Guillemin F. L’arthrose, marqueur de morbi-mortalité. Rev Prat. 2019;69(5):505–6. [PubMed] [Google Scholar]
- 12.Kollo NB, Aboubakar B, Dangui E, Diomandé M, Eti E, Koffi JE, Kouakou Ehaulier CL, Ngon Nzima HB, Ada Kanbaye MH. Formes topographiques des arthroses des membres En consultation rhumatologique à Abidjan. Eur Sci J. 2024;27:218. https://eujournal.org/index.php/esj/article/view/17901. [Google Scholar]
- 13.Shamekh A, Alizadeh M, Nejadghaderi SA, Sullman MJM, Kaufman JS, Collins GS, Kolahi AA, Safiri S. The burden of osteoarthritis in the middle East and North Africa region from 1990 to 2019. Front Med (Lausanne). 2022;9:881391. 10.3389/fmed.2022.881391. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 14.Rinaldo N, Gualdi-Russo E, Khyatti M, Lakhoua C, Toselli S. Psychosocial health and quality of life among North African women. Health Soc Care Community. 2021. 10.1111/hsc.13562. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 15.Al Saleh J, Almoallim H, Elzorkany B, Al Belooshi A, Batouk O, Fathy M, Vainstein N, Kaki AM. Assessing the burden of osteoarthritis in Africa and the middle east: a rapid evidence assessment. Open Access Rheumatol. 2023;15:23–32. 10.2147/OARRR.S390778. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 16.Mejdouli H, Amor H, Baali A, Nacer N, Chouikh J, Ouzennou N. Prevalence of depression among the elderly in Morocco. NPG. 2024;24(143):279–85. 10.1016/j.npg.2024.02.006. [Google Scholar]
- 17.Srikanth VK, Fryer JL, Zhai G, Winzenberg TM, Hosmer D, Jones G. A meta-analysis of sex differences prevalence, incidence and severity of osteoarthritis. Osteoarthritis Cartilage. 2005;13(9):769–81. 10.1016/j.joca.2005.04.014. [DOI] [PubMed] [Google Scholar]
- 18.Ravi A, DeMarco EC, Gebauer S, Poirier MP, Hinyard LJ. Prevalence and predictors of depression in women with osteoarthritis: cross-sectional analysis of nationally representative survey data. Healthc (Basel). 2024;12(5):502. 10.3390/healthcare12050502. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 19.Vogelzangs N, Kritchevsky SB, Beekman AT, Brenes GA, Newman AB, Satterfield S, Yaffe K, Harris TB, Penninx BW, Health ABC, Study. Obesity and onset of significant depressive symptoms: results from a prospective community-based cohort study of older men and women. J Clin Psychiatry. 2010;71(4):391–9. 10.4088/JCP.08m04743blu. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 20.Pan A, Sun Q, Czernichow S, Kivimaki M, Okereke OI, Lucas M, Manson JE, Ascherio A, Hu FB. Bidirectional association between depression and obesity in middle-aged and older women. Int J Obes (Lond). 2012;36(4):595–602. 10.1038/ijo.2011.111. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 21.Ye J, Xie D, Li X, Lu N, Zeng C, Lei G, Wei J, Li J. Phenotypes of osteoarthritis-related knee pain and their transition over time: data from the osteoarthritis initiative. BMC Musculoskelet Disord. 2024;25(1):173. 10.1186/s12891-024-07286-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 22.Zheng S, Tu L, Cicuttini F, et al. Depression in patients with knee osteoarthritis: risk factors and associations with joint symptoms. BMC Musculoskelet Disord. 2021;22:40. 10.1186/s12891-020-03875-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 23.Sonobe T, Otani K, Sekiguchi M, Otoshi K. Influence of knee osteoarthritis severity, knee pain, and depression on physical function: a cross-sectional study. Clin Interv Aging. 2024;19:1653–62. 10.2147/CIA.S470473. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 24.Bedson J, Croft PR. The discordance between clinical and radiographic knee osteoarthritis: a systematic search and summary of the literature. BMC Musculoskelet Disord. 2008;9:116. 10.1186/1471-2474-9-116. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 25.Brooks JM, Polenick CA, Bryson W, Naslund JA, Renn BN, Orzechowski NM, Almeida M, Bartels SJ. Pain intensity, depressive symptoms, and functional limitations among older adults with serious mental illness. Aging Ment Health. 2019;23(4):470–4. 10.1080/13607863.2017.1423025. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 26.Miller-Matero LR. Depression and pain: bidirectional relationship and changes with psychological treatment. In: Scherrer JF, Ballantyne JC, editors. Pain, the opioid Epidemic, and depression. New York (NY): Oxford Academic; 2024. 10.1093/9780197675250.003.0005. Accessed 17 May 2025. [Google Scholar]
- 27.Luppino FS, de Wit LM, Bouvy PF, Stijnen T, Cuijpers P, Penninx BW, Zitman FG. Overweight, obesity, and depression: a systematic review and meta-analysis of longitudinal studies. Arch Gen Psychiatry. 2010;67(3):220–9. 10.1001/archgenpsychiatry.2010.2. [DOI] [PubMed] [Google Scholar]
- 28.Stubbs B, Vancampfort D, Hallgren M, Firth J, Veronese N, Solmi M, Brand S, Cordes J, Malchow B, Gerber M, Schmitt A, Correll CU, De Hert M, Gaughran F, Schneider F, Kinnafick F, Falkai P, Möller HJ, Kahl KG. EPA guidance on physical activity as a treatment for severe mental illness: a meta-review of the evidence and position statement from the European psychiatric association (EPA), supported by the international organization of physical therapists in mental health (IOPTMH). Eur Psychiatry. 2018;54:124–44. 10.1016/j.eurpsy.2018.07.004. [DOI] [PubMed] [Google Scholar]
- 29.Geneen LJ, Moore RA, Clarke C, Martin D, Colvin LA, Smith BH. Physical activity and exercise for chronic pain in adults: an overview of Cochrane reviews. Cochrane Database Syst Rev. 2017;4(4):CD011279. 10.1002/14651858.CD011279.pub3. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 30.Wang ST, Ni GX. Depression in osteoarthritis: current Understanding. Neuropsychiatr Dis Treat. 2022;18:375–89. 10.2147/NDT.S346183. [DOI] [PMC free article] [PubMed] [Google Scholar]
Associated Data
This section collects any data citations, data availability statements, or supplementary materials included in this article.
Data Availability Statement
The datasets generated and/or analyzed during the current study are not publicly available due to institutional and confidentiality restrictions (data from a military hospital). However, they may be made available from the corresponding author upon reasonable request, subject to appropriate institutional/ethics committee authorization, where applicable.