A 45-year-old woman presents with loss of energy, reduced interest, and persistent low mood for 3 months. She has had two similar episodes within the last 10 years, both of which resolved with pharmacological management. Her assessment reveals absence of suicidal ideation or psychotic symptoms. She does not have marked psychomotor retardation or any other risks to herself such as refusal of drinks or meals. She has not had any manic or hypomanic episodes in the past.

Which of the following is the best next step in her management?