This clinical trial aims to assess the effectiveness of Transcranial Magnetic Stimulation (TMS) compared to Treatment as Usual (TAU) in adult patients experiencing their first or second episode of unipolar major depressive disorder (MDD). The primary end point is to determine whether TMS leads to higher rate of remission, response and greater reductions in depression severity, and improved functional outcomes compared to standard pharmacological and psychotherapeutic interventions. The trial will also explore the impact of TMS on quality of life and anxiety symptoms. Participants will be randomly assigned to either the TMS or TAU group, and outcomes will be assessed at multiple time points over a 3-year period. The trial will be conducted at Sultan Qaboos University Hospital's Department of Behavioural Medicine in Muscat, Oman, and is expected to contribute important evidence on the role of non-invasive brain stimulation in treating early-stage depression.

1.1. Background and Rationale First-episode depression (FED) comprises 50% of major depressive disorder (MDD) cases in the U.S. and contributes 80% of global disability due to mental and substance use disorders. Depression significantly impairs social and occupational functioning, ranking third among the leading causes of global disease burden for individuals aged 10-65. Untreated, FED may progress to chronic depression, addiction, and increased healthcare costs. Given the limitations of current antidepressant treatments, there is a growing need for alternative interventions, such as transcranial magnetic stimulation (TMS). TMS is a non-invasive, well-accepted therapy with emerging evidence of efficacy for depression, but its use in first-episode depression requires further research. This trial aims to compare the effectiveness of TMS versus Treatment as Usual (TAU) for adult FED patients.

1.2. Study Scope This open-label study will follow FED patients (≥18 years) with moderate or severe MDD in an outpatient setting. Exclusion criteria include substance abuse, psychotic or catatonic features, suicidal risk, or previous ineffective TMS treatment. Pregnant or breastfeeding women can participate with neurologist approval. Primary outcomes will measure depression severity and functional impairment, assessed at baseline and at four key follow-up points.

2. Methodology A randomized controlled trial (RCT) will assess the comparative effectiveness of TMS and TAU. Participants will be randomly assigned to receive either TMS or TAU, with depression severity measured by standardized scales such as the Hamilton Depression Rating Scale (HAMD-24) and the World Health Organization Disability Assessment Schedule (WHO-DAS 2.0). Baseline data and follow-up assessments will evaluate the impact of treatment on depressive symptoms, quality of life, and functional outcomes.

2.1. Study Design The study will recruit adult patients experiencing their first episode of MDD. Inclusion and exclusion criteria will ensure a homogenous sample. Participants will provide written informed consent and undergo baseline assessments before randomization into either the TMS or TAU group. TMS will be administered by trained operators using a standardized protocol. Follow-up will occur over six months, with assessments of depressive symptoms, functional outcomes, and quality of life at regular intervals.

2.2. Interventions Participants in the TMS group will receive 10 Hz stimulation at 120% motor threshold for ≤30 minutes per session. The TAU group will follow standard pharmacological and psychotherapeutic management. Safety measures include constant monitoring during TMS sessions, with anxiety management protocols in place.

Inclusion Criteria:

• Adults (≥18 years old till 64 years) diagnosed with a first or second episode of unipolar major depressive disorder (MDD).
• Moderate to severe depressive symptoms based on clinical assessment and validated scales (e.g., Hamilton Depression Rating Scale (HDRS)).
• Willingness to participate and provide written informed consent.
• Outpatient setting (not currently hospitalized for psychiatric reasons).

Exclusion Criteria:

• Current episode is not the first or second episode of MDD.
• Substance dependence or abuse within the last 6 months.
• Diagnosed with psychotic depression, bipolar disorder, or catatonic features.
• Severe depression requiring electroconvulsive therapy (ECT).
• High suicidal risk as determined by clinical assessment.
• History of unsatisfactory responses to prior TMS treatments.
• Diagnosis of Epilepsy and Epilepsy high risk group
• Pregnant or breastfeeding women, unless cleared by a neurologist for TMS treatment.