The former Barcelona and Chelsea midfielder has been hit with a 12-month suspension, however it is unlikely to affect the retired midfielder too much
The Portugal international tested positive for hydrochlorothiazide (a diuretic) and carboxy-tamoxifen (a hormone drug) in March.
Although originally sentenced to a 30-day ban in the first trial, his suspension has been lengthened enormously on Thursday, with Deco not present at court to hear the verdict.
However, the decision is unlikely to hinder the 36-year-old too much as he announced his retirement from playing professional football in August.
Deco shot to prominence with Porto, where he spent five seasons between 1999 and 2004, winning the Champions League under Jose Mourinho.
A move to Barcelona followed and he won another European crown alongside two Liga titles before a jump to Chelsea in 2008 for two campaigns.
The naturalised Portuguese attacker returned to his homeland with Fluminense in 2010 but called timed on his career this summer ahead of the latest doping verdict.