Cost-utility and Physiological Effects of ACT and BATD in Patients With Chronic Pain and Depression

The IMPACT Project's main objective is to determine the effectiveness of adding to the standard care of patients with chronic pain and mild to moderate major depression a group programme based on ACT or a group programme based on BATD and analyse the cost-utility of these psychological treatments from a health and social perspective. Likewise, both in chronic pain and in other usually associated psychiatric diseases, there is a ubiquitous lack of knowledge about what specific psychological and physiological mechanisms are modified by these third generation psychotherapies and how they relate to the observed clinical results. The potential predictors of response to these treatments are also unknown. In chronic musculoskeletal pain where central sensitization plays an important role, alterations have been found in different markers associated with an increased experience of pain. Some of these alterations in markers (e.g. high levels of pro-inflammatory cytokines) would also appear to be shared with other psychiatric diseases (major depression), a fact that would suggest a possible common mechanism involved in the etiopathogenesis of these diseases. Third generation psychotherapies have proven effective for pain management and regulation of the immune response. The IMPACT Multicentre Project (Improving Pain and Depression with ACT and BATD) will significantly expand the limited knowledge available about how ACT and BATD therapies exert their effects on relevant clinical improvement variables and will try to identify response predictive factors to these treatments.

Inclusion criteria

Patients who have been visited in the last 3 years in the participating centres and who have been given a diagnosis of chronic non-cancer musculoskeletal pain. In telephone screening, it will be evaluated whether the current pain intensity is at least moderate and PHQ-9 will be administered to confirm the presence of mild to moderate active depression.

• Patients between 18 and 70 years of age.
• Diagnosis of chronic pain (≥ 3 months) according to medical history (current pain ≥ 4 out of 10)
• Diagnosis of mild to moderate depression according to PHQ-9 (score between 5 and 19).
• Understanding of Spanish.
• Access to a Smartphone (with Android operating system).
• Written informed consent.

Exclusion criteria

• Presence of cognitive impairment according to MMSE (≤ 24 out of 30).
• Previous (last year) or current psychological treatment.
• Presence of severe mental disorder (e.g. psychotic disorder) related to substance dependence/abuse or another disease that affects the CNS (organic brain pathology or head trauma of any severity).
• Presence of serious, uncontrolled or degenerative medical disease that may interfere with affective symptoms.
• Risk of suicide (Item 9 score of PHQ-9 ≥ 2).
• Patients involved in legal proceedings with employers in relation to their illness.
• Patients with scheduled surgical intervention or other interventions.
• Inability to attend group treatment sessions.

Additional exclusion criteria for the study of biomarkers (50% of subjects in each branch):

• Cold/infection symptoms on the day of blood collection.
• Needle phobia.
• BMI > 36 kg/m2 or weight > 110 kg
• Consumption > 8 units of caffeine per day (maximum 1 drink with caffeine on the day of testing).
• Smoker > 5 cigarettes a day.
• Being pregnant or breastfeeding