Absolutely! Nothing about an antipsychotic counteracts antidepressants. Antispychotics only inhibit some dopamine and that's not generally implicated in depression. Serotonin and norepinephrine are the canonical causes of depression according to the current medical gospel. Antipsychotics are very commonly prescribed alongside antidepressants in a whole plethora of cases like bipolar and depression with psychotic features(my official diagnosis). I have in fact been on regimens with both. Infact when I am on medications, I am generally put on some antipsychotic and some antidepressant(usually a few antidepressants since my diagnosis also has a "treatment resistant" designation).
Rexulti btw is indicated specifically for use alongside an antidepressant fod treating depression. Lots of antipsychotics are. Same with mood stabilizers. For some stubbornly sad brains an antipsychotic or mood stabilizer can act as an adjunct and get the happy juices flowing when an antidepressant alone will not work.
Some antipsychotics have notable stimulating effects ironically. Abilify is notable for this. Great stuff. Too bad it gave me akithisia(a movement disorder that presents as inability to sit still and inner restlessness), and shame on all the doctors who didn't notice that symptom for the almost year I was on it, and props to the doctor who noticed it and took me off it. I thought the restlessness was caused by something else or was possibly just a feature of my mental disorder. Fun stuff.
For that akithisia I would advise that you take responsibility for your medications, do your research, and be an active decision. Maker in what and how much you take. Don't be afraid to say no. Especially with antispychs. They are prescribed a ton but they are very serious, very heavy medications that can FUCK. YOU. UP. I was experiencing a movement disorder for who knows how fucking long before a medical professional noticed and thought "hmmm I wonder if this person might be experiencing literally the most common movement disorder experienced by this particular medication which is in a class of drugs notorious for causing movement disorders in people, maybe he's not just a high strung crazy guy". Doctors make all kinds of mistakes. I'm not saying don't trust them or to trust them as much as ur bros at the gym. Just remember that many side effects might not be externally obvious even to people who be doing this for decades, and everyone makes mistakes. Sometimes a side effect is experienced entirely in your own head. Sometimes you might not attribute it to the medication (especially if it comes on a time after you start). So know what the side effects are so you know when you might need to ask to be taken off your happy pill.
is this with a doctor? If not I advise against it on the basis that it's prolly not gonna work how you want. Antidepressants have noticeable effects, at the shortest, 7-10 days into treatment. This time frame was optimistically given by a psychiatrist in an inpatient psychiatric facility who would be discharging me in 7-10 days and probably wanted to encourage some hot placebo action before giving me the boot. More realistically is 30 days of treatment to get strong identifiable benefit, and 60 days for it to reach full therapeutic effect. It's not a short time. If you can get 2 months worth of effexor then I guess cheers but then ur gonna get a therapeutic effect that will drop off over the next week you don't have it. What antidepressants giveth, she taketh away much more rapidly.
Edit: I wanna add that I do not know how of if any standard pharmacological intervention has any efficacy for specifically anhedonia if that anhedonia is not a feature of depression, dysthymia, bipolar, or some other diagnosed mood disorder. You didn't specify and anhedonia is almost universal with those who are recovering from meth and cocaine addictions and can last a year. I think I've heard some advocacy from doctors for their use and I've heard that antidepressants can lower the duration of the anhedonia due to its neurotropic factors(helps neurons repair from the damage caused by these chemicals), but I don't know how empirically corroborated this is. Since this is a forum for users of all types of substances I wanna throw that out in case your anhedonia is not entirely "organic". Also i think dysthymia requires special consideration when choosing drugs. Anhedonia absent the other debilitating depression symptoms experienced generally in an episodic manner is more likely to be dysthymia. Dysthymia is basically like depression lite. It's often(but not always) lower intensity but it is experienced continuously rather than coming in episodes. I am thought to have dysthymia in addition to the episodic depression. My brain treats DSM diagnoses like Pokémon. At least it's found a hobby..
According to Wikipedia, the only reliable medical journal that anyone can edit, the drug treatments appear to be more or less similar to normal depression but it suggests MAOIs might be slightly more effective in some instances and that treatment resistance is more common. It also says that treatment plus therapy is like...significantly more effective than just drugs. So if whoever you are getting the effexor from knows someone you can pay to talk to you for an hour a week, it might be worth looking into.
I have pretty bad anhedonic symptoms. doesn't help that I've fried my brain into a delicious meth omelette. No one told me that this would be my brain on drugs. I've tried to commit suicide a lot. And life generally feels like a waste of time when it doesn't feel like everything in my head hurts at once. So those feels, I know them. Good luck.