Mr. Jackson (52) and his wife

(49) present for couples therapy due to ongoing sexual dissatisfaction. Mr.

Jackson reports that he has had increasing difficulty maintaining an erection

during sexual activity for the past 8 months. He states that while he still

finds his wife attractive, he feels embarrassed and often avoids initiating

sex. He has no known chronic medical conditions, and his blood tests are within

normal range.

Mrs. Jackson shares that

although she understands her husband's frustration, she, too, has experienced

changes in her sexual responses. She notes that she has not felt interested in

sex for over a year and often lacks physical arousal during their encounters.

She says, “Even when we try, I don’t feel anything physically or emotionally.”

She denies pain during intercourse but admits that she is distressed by her

lack of desire.

Both partners report that the

issues began around the same time and have worsened over the past year. They

deny infidelity or significant relationship conflict. Neither is currently

taking medication, and both are in generally good health.

What is the most appropriate diagnosis for Mr. Jackson

based on the DSM-5-TR criteria?