Effect of Venlafaxine Versus Dosulepin in Pain Predominant Somatic Symptom Disorder

Effect of Venlafaxine Versus Dosulepin on Clinical Outcomes, Neuroinflammation and Cortisol Level in Pain Predominant Somatic Symptom Disorder: A Group-sequential Randomized Controlled Trial

Somatic symptom disorder (SSD) is marked by persistent physical complaints, often involving pain, alongside excessive thoughts or behaviors related to health, which substantially disrupt daily functioning. The underlying mechanisms of SSD are multifaceted. The serotonin hypothesis links low serotonin levels to the development of somatic symptoms, while the cortisol hypothesis highlights dysregulation of the hypothalamic-pituitary-adrenal (HPA) axis, with chronic stress often associated with hypocortisolism. Furthermore, the neuroinflammatory hypothesis suggests that cytokine-driven inflammation and activation of glial cells may intensify pain and somatic symptoms, exacerbating patient outcomes. Challenges such as limited acceptance of the diagnosis, resistance to treatment among patients and caregivers, and societal stigma further hinder effective management.

Currently, treatment options lack definitive efficacy, with pharmacological interventions primarily targeting serotonin pathways. There is limited exploration of therapies addressing mechanisms like cortisol dysregulation and neuroinflammation. Commonly used medications include tricyclic antidepressants (TCAs), serotonin-norepinephrine reuptake inhibitors (SNRIs), and selective serotonin reuptake inhibitors (SSRIs), with prescribing decisions often based on physician discretion and patient tolerance rather than clear evidence favoring one class over another.

The proposed study aims to compare the efficacy and safety of Dosulepin (a TCA) and Venlafaxine (an SNRI) in managing SSD patients with predominant pain. By evaluating their impact on symptom severity, quality of life, and biomarkers such as serum cortisol and TNF-alpha levels, this research seeks to enhance understanding of SSD treatment. The findings aim to address gaps in SSD pharmacotherapy and contribute to improved patient care strategies.

Inclusion Criteria:

• Patients with a primary diagnosis of somatic symptom disorder with pain predominance (DSM-5).
• Patients of either sex within the age group of 18-65 years.
• Patients with PHQ-15 score of ≥ 5.
• All included patients will be treatment-naïve or have not received any treatment in the last 4 weeks.
• Patients who have given written informed consent.

Exclusion Criteria:

• A diagnosed psychological condition that might require other treatment (e.g., psychosis, suicidality)
• Patient undergoing current psychotherapy.
• Patients with cognitive impairment.
• History of allergy to either of the study drugs (dosulepin or venlafaxine).
• Patients with comorbidities like any malignancies, hepatic, renal, cardiovascular, neurological or endocrinal, or respiratory dysfunction.
• Substance abuse history of psychoactive agents.
• Pregnant and lactating mothers.