MDouglasCourt042010_08_X17230.jpgCameron Douglas, son of actor Michael Douglas, has been sentenced to four additional years in prison for taking drugs while in jail. He was originally jailed in April 2010 on a five-year sentence for dealing meth and cocaine ... and possessing heroin.

The 33-year-old inmate reportedly asked the judge to "consider his crime a consequence of drug addiction." In court, Cameron told the judge, "You see your honor, I cannot seem to find comfort in my own skin."

Despite Douglas' plea, the judge said he needed a harsher punishment for his pattern of "reckless, disruptive and non-compliant" behavior.

Combined with his previous sentence, Douglas must now serve nine years total behind bars.