Samantha Ronson is reportedly suffering from depression.

The 31-year-old DJ was accompanied by girlfriend Lindsay Lohan as she visited Los Angeles' Cedars-Sinai Medical Center?on Dec.21 - less than a day after it was reported she had been making frantic phone calls to friends complaining of stress and exhaustion.

A source told Life and Style Weekly magazine: "Samantha was calling around. She has been suffering from depression and from lack of food and sleep. Lindsay has been helping her through this as she has been through it herself two years ago."

Doctors were reportedly called to Samantha's home shortly before she visited the medical facility.

Despite her trip to Cedars-Sinai being described as "relatively minor", witnesses say Samantha was taken into the hospital in a wheelchair through the emergency entrance.

Lindsay, 22, has previously undergone three stints in rehabilitation clinics for treatment for drug and alcohol addiction.