Table 4.

Summary of interventional studies.

Population	References	N for intervention/control	Intervention	Depression/anxiety	Outcomes
PAH	Li et al. (30)	55/59	Progressive muscle relaxation	Intervention for depression and anxiety	PMR group showed significant improvement in anxiety, depression, overall QOL and QOL-MCS, but not QOL-PCS or 6MWD (p < 0.05). Control group showed no significant improvement in any of the variables. The control group showed no significant changes in distribution of the HADS-Anxiety and the HADS-Depression scores after intervention compared with that at baseline. In contrast, the number/proportion of patients with an anxiety (p < 0.01) or depression score (p = 0.01) less than 8 markedly increased in the PMR group after intervention compared with that at baseline.
	Matura et al. (42)	10/0	Slow-paced respiration therapy (using the RESPeRATE device)	Intervention for depression only	Slow-paced respiration therapy was found to decrease the severity of depression in the population. PHQ-8 scores decreased from a baseline mean of 4.2 to a follow up-mean of 2.9 after undergoing eight weeks of therapy.
	Von Visger et al. (43)	14/0	Urban Zen Integrative Therapy	Intervention for anxiety only	Reductions in ratings of pain, anxiety, fatigue, and dyspnea symptom severity before and after the weekly UZIT sessions were reported (p < 0.0001). Symptom severity did not differ from week 1 through week 6 indicated that there was no cumulative dose/effect detected. Analysis indicated that about 50% of participants reported the absence of bothersome symptoms.
CTEPH	Vanini et al. (41)	70/0	Pulmonary endarterectomy (using moderate hypothermia and periodic circulatory arrest)	Intervention for depression and anxiety	Prior to surgery, mean baseline score of HADS-D was 6.11 while mean score for HADS-A was 7.70. Three-month score decreased to 4.48 and 5.95 for HADS-D and HADS-A respectively. Generalized linear p-value was calculated, and scores on both scales had significant changes post-surgery, with HADS-D (p = 0.002) and HADS-A (p < 0.001). Surgical factors and its association with depression and anxiety was also investigated. Anesthesia duration was concluded to significantly lower depression (HADS-D, p = 0.02) and anxiety (HADS-A, p = 0.08) scores. A longer total circulatory arrest (TCA) duration was also a significant relation to lower depression scores (HADS-D, p = 0.03)

PAH, pulmonary arterial hypertension; CTEPH, chronic thromboembolic pulmonary hypertension; PMR, progressive muscle relaxation; QOL, quality of life; MCS, Mental Component Score; PCS, Physical Component Score; 6MWD, 6-min walk distance; HADS, Hospital Anxiety Depression Scale; PHQ, Patient Health Questionnaire; UZIT, urban Zen integrative therapy.