Aim and Objectives:This study examined SSRI-related adverse drug reactions (ADRs), medication adherence, commonly prescribed SSRIs, and gender and age distribution in patients with depression at three tertiary care hospitals in Kerala, India. Materials and Methods: The prospective observational study was conducted in the psychiatry departments of Al Azhar Medical College Hospital in Thodupuzha, Mount Zion Medical College Hospital in Adoor and Christuraj Hospital in Kottarakara. A predefined WHO form was used to evaluate ADRs. A study-specific data collection form was used to record demographics, clinical details, and prescribed drugs following a unified research protocol. In addition, the WHO causality scale, the Naranjo Probability scale, Hartwig's severity assessment scale, and the Modified Shumock and Thornton Preventability Scale were also used to evaluate ADRs. Results: Among the 230 patients (female, 56.52%; depression prevalence age 21-40, 57.83%) who took SSRI, 26.87% reported ADRs. Depressive mood disorder was the most prevalent diagnosis, affecting 47% of patients, followed by generalized anxiety disorder (17.3%). Escitalopram (60.43%) was the most prescribed SSRI for depression, followed by fluvoxamine (21.74%). ADRs were predominantly observed in the cardiovascular, neurological, and gastrointestinal systems. Nausea was the most common ADR (25.77%), followed by insomnia (22.68%), lethargy (16.49%), and headache (11.3%).43% of the ADRs were 'probable causality.' Among all the ADRs, 54% were preventable. 64% of the ADRs were mild in their severity. Escitalopram, the most prescribed medication, was the primary cause of ADRs, with fatigue being particularly prevalent. Non-adherence to SSRIs was common, especially with escitalopram, often due to missed doses. Conclusion: This study shows the prevalence of depressive mood disorders in the population examined. SSRIs like escitalopram and fluvoxamine often cause insomnia and nausea when prescribed for depression. Clinical pharmacists are crucial to patient counselling and education. Targeted strategies are needed to reduce antidepressant nonadherence due to multiple factors. Given the dangers of untreated depression, such as suicide, public health requires effective depression management.