Antipsychotic medication, over time, affects brain structure. When, like me, you have been on medication thirty years, (nearly all of my adult life) medication becomes a factor in how the brain develops.
Make no mistake; Schizophrenia is a very pernicious illness. Not treating this illness has a much worse effect on someone's development compared to the problems that come with treatment.
The physical side-effects of antipsychotic medication seem worse than limitations introduced to cognition. Physically, you can get "Parkinsonian" symptoms, which are parallel to having Parkinson's. This is because antipsychotic medications block neurotransmitters such as Dopamine. Parkinsonian side effects are the tip of the iceberg of medication side effects. I do not have space here to cover them all. (Medications are prescribed to help with side-effects, yet they have side effects of their own.)
However, it has been my experience that meds don't reduce intelligence. If anything, they help with intelligence by reducing psychotic symptoms which would otherwise interfere with intelligent thinking.
Some medications, for some people, can interfere with concentration, and can make it very uncomfortable to read or to do tasks that exert one's mind. This is not the same thing as reducing intelligence. The intelligence still exists albeit could be hampered at some tasks. Depending on the dosage of antipsychotic meds, how long they have been taken, and other factors, it is possible to push past this difficulty concentrating. In the long term, if you do things that intensively use the mind on a regular basis, you will probably eliminate the difficulty by means of exercise.
Lack of exercising your mental capacities will make them more likely to wither away. If you take medication but do not stay active, you might lose mental capacity due to atrophy of the brain. However, even for someone without a psychiatric illness who never needed or took psychiatric meds, lack of using the brain can cause the brain to lose functioning.
It has been my experience that medication doesn't block mindfulness, meditation or spirituality. Being in a psychotic mode (due to lack of medication) will completely prevent you from practicing meditation--I can almost guarantee that. Achieving meditative "attainment"--which is a word that describes some degree of being "enlightened"--is more difficult for someone with mental illness than it is for a non-afflicted person, but most of this added difficulty isn't caused by the medication.
(The quest for meditative attainment is quite a challenge for anyone, mentally ill or not, and any progress, even a little bit of progress, is valuable.)
After thirty years on antipsychotic meds, I can no longer work at a full-time job, an ability I once had in my distant past. I can not handle physically demanding situations. I can't do tasks that entail moving fast.
Because of the combination of the medication and relapses of the illness, it is likely that my brain is prematurely aged. For one thing, I experience some amount of memory problems. However, some of my problems are hard to distinguish from the normal effects of aging.
Going on and off medication on a repeat basis is very bad for the brain. If medication is needed, you should take it and keep taking it. Going off medication and then relapsing is a shock to the brain cells. When medication is reinstated and reality is restored in the mind, you may realize you've had quite a big setback.
With every relapse into severe psychosis, gray matter is lost. Medication has some effects that may be bad for the brain, but if medication is needed, then doing without it is far more harmful.
You wouldn't expect that you would pitch at the World Series if you had two broken arms. Those arms need to be put in a splint and allowed to heal. The same goes for your brain--medication is equivalent to a splint.
In another analogy, if you had diabetes, you would want to take diabetes medication to prevent damage to your organs as well as other life-threatening problems. Medication to treat psychosis prevents brain damage to important parts of the brain which occurs through an episode of severe mental illness.
I have been on heavy dosages of antipsychotic meds for thirty years now. If medication were really that bad for me, I wouldn't be able at this point to go to the store and buy a loaf of bread, much less write this column. Being heavily medicated on a long-term basis apparently isn't nearly as bad for me as it would have been if I were determined not to take medication. Many people may mistakenly ascribe some cognitive problems as being caused by medication that are actually caused by the illness.
After thirty years on medication, certain things don't function as well as they did when I was in my twenties. However, I can say that my logical thinking ability is better than it ever was. I have had nearly eighteen years recovery (since my last relapse due to stopping medication) under my belt. This has allowed a brain that's mostly very good to recover and to serve me well.
It is a shame that the medications that help us stabilize have so many side effects that ruin our health as well as inducing physical and mental suffering. Assuming that there is no hidden agenda, we need more research to invent medications that work for us without ruining our lives in the process.
* * * My books, including but not limited to "Instructions for Living with Schizophrenia: A Self-Help Manual," are available on Amazon. I can be reached at: firstname.lastname@example.org However, I can not give any advice.