The inclusion criteria were as follows: (1) Participants: patients included were diagnosed with PSD with no restrictions on diagnostic criteria, gender, age, race, onset time, or source of cases regardless of the cause of the stroke. (2) Interventions: the aromatherapy interventions consisted of inhalation or massage therapy with essential oils bathing, and so on. There were no restrictions on the type of essential oils administered. (3) Comparisons: the control interventions could be placebo, antidepressants, routine care, or other methods. (4) Outcomes: the primary outcome included the HAMD score or other depression scales. (5) Study Design: randomized controlled trials.

The exclusion criteria were as follows:(1) Duplicate publications. (2) Literature for which it is not possible to access the full text and extract valid ending indicators. (3) Literature not in Chinese or English.

Two independent reviewers extracted data from selected RCTs. The essential characteristics such as first author, country, number of treatment and control groups, type of aromatherapy, duration of aromatherapy, type of control intervention, and outcome measures. Any disagreements were reviewed by a third reviewer and resolved by discussion among all reviewers.

The methodological quality of the included studies was assessed by two researchers (Jing Chen, and Yaxuan Yan) according to the Cochrane Handbook. Each study was assessed as follows: the risks of selection bias including random sequence generation and allocation concealment, blinding of participants and personnel, blinding of outcome assessment, incomplete outcome data, selective reporting, and other biases. If necessary, we contacted the study authors when relevant information could not be identified from the articles or supplementary materials. In addition, we graded the overall quality of the included trials as high, moderate, or low quality according to previously published high-quality literature. Disagreements were resolved through discussion with a third researcher (Jindan Lv).

Meta-analysis was conducted using RevMan 5.4. In cases where the heterogeneity between studies was p > 0.1 and I² < 50%, the fixed-effect model can be chosen. Conversely, if the heterogeneity between studies was p ≤ 0.1 and I² ≥ 50%, the random-effect model was used. If the heterogeneity was too large or there was no way to determine the source of heterogeneity, descriptive analysis was used instead.

The initial search yielded 530,964 relevant articles. After excluding duplicate and irrelevant literature, 1,341 articles remained. Following a preliminary screening by reading titles and abstracts, 320 articles were initially included. Subsequently, after reading the full texts, 310 articles were excluded due to mismatched outcome measures or intervention methods. Upon a second full-text review for further screening, 10 articles were ultimately included in the meta-analysis. The flow chart of the process of study selection is shown in Figure 1.

The characteristics of the included trials are shown in Table 2. All 10 studies were conducted in China, involving a total of 863 PSD patients (9–18). The sample sizes of the included trials ranged from 20 to 50. The treatment duration varied from 4 weeks to 8 weeks, with an average of 6 weeks. 5 trials used aromatherapy alone (11–14, 17), while the rest compared it with other treatments such as auricular point sticking, sertraline, and repetitive transcranial magnetic stimulation in the control groups to explore the effects of combined use of aromatherapy. Table 2 shows the details and characteristics of the included RCTs.

All the literature mentioned randomized grouping, among which 6 articles used the random number table method for grouping (10–12, 15, 16, 18). 1 article used convenience sampling (17), and the remaining 3 articles only mentioned “randomization (16–18).” One article explicitly stated that the study adopted a single-blind trial (9, 13, 14), while the others did not mention the concealment of allocation methods or the implementation of blinding. There was one study with drop-out cases, but it did not affect the overall results. The research data were complete, all literature was reported as originally planned, baseline data were comparable, and there were no other biases. The quality assessment is shown in Figure 2.

The studies were grouped based on the duration of aromatherapy intervention (≤4 weeks, >4 weeks), with 6 studies intervening for 4 weeks (9, 10, 13, 14, 16, 18), 3 studies for 8 weeks (11, 12, 15), and 1 study for 30 days (17) (Figure 6). Subgroup analysis was conducted according to the type of aromatherapy, categorized into essential oil inhalation, traditional Chinese medicine inhalation, and essential oil inhalation combined with essential oil massage. Among them, 2 studies adopted inhalation combined with massage, 2 studies adopted traditional Chinese medicine inhalation, and 5 studies used inhalation alone (Figure 7). The results showed that TCM aromatherapy interventions in each subgroup effectively alleviated depressive symptoms in patients with PSD. However, the heterogeneity among subgroups did not completely disappear, indicating that the aforementioned factors were not entirely the source of heterogeneity.

Sensitivity analyses of depressive symptoms in PSD patients treated with TCM aromatherapy were performed, and the heterogeneity was not significantly altered after excluding each study one by one. Due to the limited inclusion of literature, a funnel plot could not be drawn to determine publication bias.

Limitations of this study: (1) Evaluation metrics: Among the 10 included randomized controlled trials, the assessment indicators for depression were not consistent. Current research primarily focuses on scale scores, with only a few incorporating physiological indicators. It is recommended that future researchers adopt more objective metrics to ensure the objectivity and authenticity of the studies. (2) Study design: Most of the included studies had short intervention durations and did not involve long-term follow-up after the intervention. Therefore, the long-term effects of traditional Chinese aromatherapy on depression remain unclear and warrant further in-depth research. (3) Sample size: The sample sizes in the included studies were relatively small. Future studies could increase the sample size to enhance the generalizability of the conclusions. (4) Literature quality: The majority of the included studies had suboptimal use of randomization and blinding methods, resulting in lower quality ratings. The assessment methods and intervention measures in the included literature were not entirely consistent, which may affect the stability of the findings.

In summary, the results of this meta-analysis suggest that TCM aromatherapy has a certain improvement effect on depressive symptoms in patients with post-stroke depression. However, due to the generally low quality of the included literature, higher-level and higher-quality studies are needed to confirm the accuracy and reliability of the results. Additionally, larger sample sizes and longer-term studies are required to validate further the effectiveness of TCM aromatherapy in alleviating depressive symptoms in PSD patients, thereby providing more reliable evidence for improving patient comfort and quality of life.