Can you combine taking cymbalta (duloxetine) and naltrexone for depression?

Probably: Cymbalta (duloxetine) for depression is fine. I find no indication for the use of Naltrexone in depression. If you are referring to just having to use the two at the same time, i find no contraindication for using the two together, ie, no drug to drug interaction. Both drugs are for serious illness and make shure you thoroughly discuss this with your pcp, addiction md, other provider or pharmacist/pharmd.

Yes: There is no contraindications to that combination.

Naltrexone: The only literature of which I am aware of Naltrexone being used to decrease depression would be the theory of low dose naltrexone.There is some evidence that low-dose Naltrexone (ldn) can upregulate endogenous opioid activity and  may have a role in promoting stress resilience, exercise, social bonding, and emotional well-being, as well as amelioration of psychiatric problems such as depression.