According to Jim (2001)

S7E15 The Six-Week Curse

In an effort to uncover the reason behind Andy's brief romantic flings, Dana hypnotizes him, revealing that his struggles stem from deep-rooted low self-esteem. Determined to help, Dana attempts to elevate Andy’s confidence. However, her well-intentioned efforts backfire when Andy, feeling more self-assured, begins to flirt with other women while on a date with Emily, creating tension and complications in their relationship.