A patient with decreased interest in sexual activity affecting their partner may be suffering from which disorder?

The correct response pertains to Hypoactive Sexual Desire Disorder, which is characterized by a persistent or recurrent deficiency in sexual desire. This condition often leads to distress or interpersonal difficulties, particularly when the decreased interest affects a partner. Such a lack of interest can manifest as a diminished desire for sexual activity that significantly impacts relationships and partners' feelings.

When considering the other options, Erectile Dysfunction primarily involves difficulties in achieving or maintaining an erection during sexual activity rather than a lack of interest. Sexual Aversion Disorder is characterized by the aversion or avoidance of sexual activity often due to fear or anxiety, which is different from a simple decrease in desire. Premature Ejaculation, on the other hand, relates to the timing of ejaculation rather than interest in sexual activity itself. Thus, the nature of the disorder most clearly aligning with decreased interest affecting a partner is indeed Hypoactive Sexual Desire Disorder.