For more than 30 years, researchers have known that meditation can have negative effects on some people, including physical and psychological problems such as insomnia, muscle spasms, anxiety attacks, hallucinations and psychotic breakdowns. According to Maggie Phillips, Ph.D. (specializing in hypnosis), she has known people who would go to five to eight day long retreats and would be basket cases at the end.
Sense of Failure
For some people, the urge to meditate is strong. Despite investing much time to learn how to do it correctly, they fail. Therefore, the person grieves the loss and feels worthless.
Covering Up the Problem
Louis Nordstrom, a professor and Zen master, was abandoned by his mother in childhood. To help deal with his pain, he would meditate. Although he found comfort through meditation, he realized he was continually going through bouts of depression. He discovered through therapy that meditation was only covering up his pain (detaching himself from his emotions and others) and not treating it, thus leading to the bouts of depression.
According to Ananda Sangha, only a small percentage of people are at risk of not benefiting from meditation—people who are deeply disturbed. This can include people who are severely depressed or who are paranoid schizophrenics. This doesn't necessarily mean it is dangerous for them. It is said that silent sitting meditation has not worked well for people suffering from severe psychosis; however, it is possible it can make matters worse.
Detachment techniques are meant for nuns and monks, meaning they take a vow of celibacy, poverty and obedience. People practicing some types of meditation (such as Buddhist or Hindu teachings) have become depressed because they have been cut off from life.