Final answer:
The focus on communication issues and solving interpersonal problems in relationships as a contribution to depression is indicative of the use of interpersonal therapy.
Step-by-step explanation:
If the focus of your therapist is on how communication and problem-solving difficulties with your partner are contributing to your depression, your therapist is most likely using interpersonal therapy (IPT). IPT is a therapy that addresses the interpersonal issues of depression with a strong focus on relationship problems and social functioning. It is different from cognitive therapy, which primarily focuses on changing negative patterns of thinking, and cognitive-behavioral therapy, which combines cognitive and behavioral strategies to treat mental disorders. Couple therapy, while it involves working with both partners, may not directly address one's individual depression unless it is specifically framed within an interpersonal therapy context for depression.