"I am as gutted as everyone else, but change will not move us forward," he told supporters forum talkforest.com in a statement.
Doughty added: "We will be in the same situation this time next year with another 'promising' manager and will not have eradicated the comfort zone culture in the dressing room.
"This will take time, but Gary has my full financial support.
"This is a long job and if we have the wrong man then that is costly for me and painful for all of us as Forest fans.
"At that stage I will hold up my hands and say that we got it wrong - but we need to give Gary a couple of years to finish the job he started last year."