Reducing depression medications

I've been on effexor xr for about 4 and a half years.  I'm now at 150mg a day (started at a low dosage and it's been increased 3 times over the years), it was last increased about a year ago.  I've recently been diagnosed and treated for sleep apnea which I've had for several years but only recently treated.  I'm feeling the best I have in years.  My sleep dr mentioned that sometimes antidepressants can be reduced once treatment for sleep apnea starts as sometimes the depression symptoms are from the sleep apnea.  Is this true?  How will I know if it's right to discuss reducing my dosage with my doctor?  I know when to discuss with my dr when the dosage "feels" too low but how do you know if the dosage is to high and should be reduced?

[Roger Gould, M.D.]

You know only by experimenting. Your sleep therapist may be right, its worthwhile talking to your doctor about lowering the dose and see what happens.