Nobody had anhedonia until neuroleptics/antipsychotics(APs) were invented!
Theory of negative symptoms is just what pharma manufacturer's made (and teach on colleges) as self protective mechanism.
Paliperidone mechanism of action:
is opposite of heroin, molecular structure is the same except they use Flourine which acts antagonistc and is very aggressive with much more lasting effects since it sticks to receptors and won't let go which also gives metabolic stress to receptors protein which aren't "unbreakable/unchangeable" thus causing changes which affect their functionality in long term even after quitting, resulting in inflammation since microglia will be detecting receptor damage and sending many repair messages to neuron cells, they also assist in replacing synapses and replacing receptors.
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I'm 2 years off and still experience severe anhedonia, around halfways recovered from it, and still recovering, noticing some progress every month, especially visible every 4 months.