Underdosing of other antidepressants, initial encounter

This code signifies that a patient has intentionally or unintentionally taken less than the prescribed amount of an antidepressant medication, excluding tricyclic antidepressants and monoamine oxidase inhibitors (MAOIs). This underdosing can lead to a recurrence or worsening of the underlying depressive symptoms.

Apply this code when a patient presents with symptoms related to insufficient antidepressant medication (e.g., selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, atypical antidepressants) and the underdosing is identified as the cause. This is appropriate for the initial assessment and treatment of the underdosing event.

• Always use a secondary code to identify the specific antidepressant drug that was underdosed.
• Ensure documentation clearly supports that the underdosing is the reason for the current encounter.
• Distinguish from noncompliance (Z91.120-Z91.128) if the underdosing is not the primary focus of the encounter.