Lamar Odom -- He Really Did Tweet About Kardashians

Lamar Odom did indeed tweet his support of the Kardashian family earlier this week -- contrary to what his friends are saying.

An angry tweet -- purportedly from Lamar -- went out a few days ago, in response to his father claiming the Kardashians are the reason he's fallen into a deep, dark hole.

The tweet trashes his dad, and then praises the Kardashians -- "He disrespecting the ONLY FAMILY that has loved me without expecting anything in return," adding, "They are the ONLY ones that have been here consistently 4 me during this dark time."

A source close to the Kardashian family tells TMZ ... just before pressing the button, Lamar called the family, saying he was about to tweet the message.