BackgroundDrug-induced parkinsonism (DIP) is the most common movement disorder induced by antipsychotics. Although DIP is mostly symmetric, asymmetric DIP is...
www.frontiersin.org
Around 18% to 54% of people taking antipsychotics get drug induced parkinsonism (DIP) with hospital populations the highest amount. Some studies indicate 54%. Up to 30% of patients with DIP may develop a persistent or progressive parkinsonian syndrome (PPS). This literally indicate consistent and continuous damage to the dopaminergic systems.
Lets say you grab 1000 patients taking antipsychotic and median of 35% of them get DIP that's roughly 350 patients. 30% of those patients get PPS that's roughly 115. So for each 1000 people taking antipsychotics 115 get chronically ill and develop damage to the dopaminergic system. Roughly 10,5% doesn't recover. I personally think numbers for paliperidone depots are at the highest rate because paliperidone is known to cause DIP. Also hospitals where they force haldol injections would probably have highest percentage of people affected. You don't have to have a high dose or high dosage frequency to develop it.
If you assume 54% DIP rate for paliperidone shots its close to 200 cases with PPS per 1000 taking those shots. That's roughly 20% who doesn't recover at all.
At higher dosages it's accompanied by neuroleptic induced deficit syndrom (NIDS) which is another syndrom that manifest with high dosages of antipsychotics (especially depot shots)
en.m.wikipedia.org
Recovery rates and chances on recovery can probably estimated by observing how many DIP and NIDS symptoms people develop and how severe those particular symptoms are.
@dirtyinvega mentioned he developed fullblown parkinsons in high intensity. Another user on youtube (with almost no recovery at year 4) also complained about severe EPS (extrapyramidal symptoms / movement disorders ) and burning pain in the brain (burning brain syndrome). If you don't develop these symptoms including NIDS in high intensity chances are high you're going to (partially or full )recover.
Just my 5 cents