What if a patient can't determine on their own if they should trust their psychologist's assessment because they themselves are not qualified? They can essentially be brainwashed without even knowing it.Of course you can scientifically measure it. Standards of care and the relevant procedures are established by experts. The recipient of care will determine if it works for them, and whether the recipient is feeling better can also be assessed by the psychologist themselves. If it does not work, the patient will change psychologists and if it does work and they are happy, which is the case 99.99% of the time, then proper consultation, advice and care has been provided.
Yup, kids should not see psychologist, because like 0.1% of psychologists suck at their jobs.
You should not go to the ER in the event of an emergency, because 5% of the cases are misdiagnosed.
You should not go see your family doctor, because in a minority of cases, they miss something.
You should not take a flight, because some pilots commit errors leading to plane crashes.
You should not buy meat from the grocery store, because sometimes meat is recalled due to salmonella poisoning.
You should not drive, because many a times there are accidents that kill people.
You should not play sports, because many a times, people experience injuries.
You should not go to the gym, because sometimes, people sprain their ankles.
You should not book a provider, because sometimes people contract STIs.
You get the idea. Talk about being a snowflake rightie.
One more to add to your list...
You should not cut your dick off based on a shrink thinking you need to so you feel better.