Referral to study (stage 1): 1. Age ≥ 60 years. 2. Attends one of 18 participating Seattle, NYC, or Tampa area senior centers. 3. Patient Health Questionnaire (PHQ-9) score of ≥10 via routine screening. Research assessment (stage 2): 1. Clinically-assessed HAM-D>14 2. Mini-Mental Status Exam (MMSE) ≥ 24 OR modified Telephone Interview for Cognitive Status (mTICS) ≥ 19 3. Off antidepressants or on a stable dose for 12 weeks. 4. Capacity to provide written consent for both research assessment and the BA intervention. Client Participants

1. Current active suicidal ideation. 2. Presence of psychiatric diagnoses other than unipolar, non-psychotic major depression or generalized anxiety disorder by SCID-V (Structure Clinical Interview for DSM-V). 3. Severe or life-threatening medical illness (e.g., end stage organ failure). 4. Inability to speak English or Spanish Volunteer Participants (anticipated enrollment: 36) Inclusion Criteria 1. Age ≥ 60 years. 2. Attends one of the participating Seattle, NYC, or Tampa-area senior centers. Volunteer Participants Exclusion Criteria 1. Current major depressive disorder, alcohol or substance abuse, or manic, hypomanic, or psychotic symptoms (SCID-V); 2. Mini-Mental Status Exam (MMSE) ≥ 24 OR modified Telephone Interview for Cognitive Status (mTICS) ≥ 19; 3. Inability to speak and read English or Spanish Clinician Participants (anticipated enrollment: 36) Inclusion Criteria 1. Master's degree in social work, counseling, marriage/family, or other clinical mental health degree 2. English or Spanish Speaking 3. Capacity to provide consent for all study procedures 4. Willing to audio record study sessions for supervision and evaluation Clinician Participants Exclusion Criteria 1. Non-English or Non-Spanish speaking 2. Does not hold a Master's degree in social work, counseling, marriage/family, or other clinical mental health degree 3. Unable to provide consent 4. Unwilling to audio record study sessions for supervision and evaluation