California Gov. Jerry Brown recently signed a law that bans therapy aimed at changing minors' sexual orientation from gay to straight. Are any other kinds of psychotherapy illegal? Yes, but not many. The only kinds of therapy to be banned or restricted in the United States are ones that are violent or that involve certain psychoactive drugs.
"Rebirthing therapy," which aims to reproduce the physical experience of labor in order to help children feel reborn, was outlawed in Colorado and North Carolina in 2001 and 2003 respectively in response to the asphyxiation death of a 10-year-old girl during a rebirthing session.
The U.S. House also passed a resolution opposing the therapy (but not outlawing it). The American Psychological Association does not recognize rebirthing therapy, which ostensibly promotes a closer attachment between parent and child, as a legitimate form of psychotherapy.
Psychedelic therapy, the use of hallucinogens to facilitate the treatment of depression, addiction and other psychological problems, is widely illegal. Psychedelic drugs like LSD, psilocybin, MDMA and iboga are considered by the Drug Enforcement Agency to have "no currently accepted medical use in treatment in the United States," and therefore psychotherapists cannot treat patients with them outside of tightly controlled clinical studies that have been approved by review boards.
Electroconvulsive therapy, a treatment for severe depression and bipolar disorder known colloquially as electroshock therapy, is subject to certain state regulations. In Texas, minors and patients who have not given informed consent to the treatment may not legally be subjected to electroconvulsive therapy. Similar restrictions on electroconvulsive therapy exist in other countries around the world.
In general, psychotherapists and counselors are licensed by state psychology boards. Those who violate the codes of practice are subject to having their licenses revoked, and people who practice therapeutic techniques without a license can be prosecuted, much like people who practice medicine without a license.