LOS ANGELES (AP) - Michael Jackson's ex-wife has acknowledged her concerns that some of the entertainer's frequent medical visits were motivated more by a desire for drugs than by the treatment he received. Debbie Rowe testified on Thursday that she expressed the concerns to Jackson when he would go to his longtime dermatologist more than once a week in the 1980s and early 1990s. Rowe is Jackson's ex-wife and worked in the office of dermatologist Dr. Arnold Klein. Rowe, a former medical assistant for Klein, previously told jurors that all of Jackson's medical procedures were tied to treatments for skin conditions or scars he sustained after being injured during a commercial shoot. She acknowledged her concerns about drugs under questioning by a lawyer for AEG Live LLC, which is being sued by Jackson's mother in a negligence case. AEG denies it is liable for Jackson's June 2009 death.