Is it possible for a psychologist harm you?

Yes. There are multiple incidents where "bad" psychologists have mentally scared children through the pushing of their own pet ideas at the expense of their patients.

Many of their victims are children. Pop psychologists tried to push weird and wacky ideas on raising children, or getting children to behave in a certain way, and ended up warping the children.

One of the most infamous was Dr. John Money, who conducted unethical and barely legal sexual empowerment no children in order to "prove" his own pet idea that sexuality was down to nurture rather than nature. He attempted to convince a pre pubescent boy with no history of LGBT tendencies that he was a transsexual/wanted to be a girl.

yes. psychologist are the people who carry out psychological experiments and many experiments over the years have harmed humans and animals both phisically and psychologically. although these days they try their best to be ethical.

the guy above my answer has mistaken psychologist with therapist, and maybe you have to.

but its possible for anyone to harm you!!

Yes. A successful therapeutic relationship depends on trust and respect. If a therapist betrays the client's trust (eg by revealing private info to others or behaving sexually or unempathically), it can destroy the therapeutic relationship, promote hurt, shame, guilt, and anger in the client, and sour her/him on the benefits of effective professional therapy.

yes . if they use neuro linguistic techniques in a bad way they can actually BRAINWASH you look up neuro-linguistic programming techniques NLP .