A word of caution, for medical reasons - Meditation is NOT everyone's bag...
Excerpt: A woman in her mid-20s, turned to meditation as a way to feel connected. "I wanted to experience that 'oneness with the universe,'" she says. "Then I began hearing voices," she says. "I heard profound messages. The other people thought it was a sign of enlightenment. Some people at the temple told me that I had 'contacted a spiritual guide.' During my normal awake hours, I found myself feeling spacey sometimes." Unconvinced that aural hallucinations were a sign from God, Long quit meditating. The voices stopped. Long's experience isn't unique. Researchers have known for 30 years that meditating can have adverse health effects on some people, inducing psychological and physical problems ranging from muscle spasms to hallucinations. But around the Bay Area, eyes seem closed to the data. (Sandy Brundage link)
For some the result of using meditation can be mind filled chaos - due to meditations' known affects on neurological underpinnings... Brain imaging was done while one individual entered into a meditative trance; that imaging indicated - his brain bloodflow patterns showed that the temporal lobes were certainly involved but also that the brain's parietal lobes appeared almost completely to shut down. The parietal lobes give us our sense of time and place. Without them, we may lose our sense of self. (link)
For some who use meditation the goal actually is to lose sense of self - for a variety of reasons. For others, meditation is simply a benign way to relax. Still, there is a physiology that occurs and it does have significant consequences for some.
Researched affects from meditation are as follows:
relaxation-induced anxiety and panic
impaired reality testing
confusion and disorientation
Meditation Alters serotonin levels - During meditation, the brain releases serotonin. People with mild depression might enjoy the increased levels of serotonin because the neurotransmitter can ease their mood. Drugs like Prozac mimic this effect. However, too much serotonin can cause all of the symptoms of Relaxation Induced Anxiety, according to Dr. Solomon Snyder, head of Neuroscience at Johns Hopkins University. In some cases of schizophrenia, an excess of serotonin coupled with meditation can drop-kick someone into psychosis.(link)
A number of negative side effects correspond to the presence of excess serotonin; muscle twitches and convulsions, headaches, stomach and bowel complaints, fatigue, insomnia and other sleep disorders, inability to focus -- feeling "spacey", anxiety and panic attacks, depression, dissociation and depersonalization, nervous breakdown and suicidal ideation.
Hello, Dr. Wells shows what meditation does to my daughter. I never understood why meditation acted upon her as it did. As I researched the meditation issue a bit because of all the news the subject, I came to understand that serotonin is my autistic daughter's enemy since it was apparently too abundantly supplied - in her case.
Everyone tried so hard to help, but the fact for the current time was that we were not dealing with anything near normal, and Sarah was not responding to most of these types of interventions normally. Her world represented an upside down one. Things considered soothing by many, became intolerable for Sarah.
Another therapist wanted to help Sarah to utilize certain relaxation techniques. Mostly, breathing exercises and music. The deliberate breathing required repetition, or ritual. How could I explain to the therapist that this meditative breathing might be bad? Ritual proved harmful to Sarah, and the repetitive breathing might contribute to future absence spells. Past absence spells disturbed her enough to result in violence and/or screaming. Music and repetition (rote) agitated her. Sarah tried relaxation with the therapist, and she engaged in the deliberate breathing, but she looked disturbed; the way she usually looked when dealing with internal conflict. Sarah’s thought processes were fried, and that made repetition of any sort an enemy. Meditation upon meaningless music, breathing, or idle thinking was in vain. It really pointed to her susceptibility toward spells, as compared to some individual’s susceptibility to hypnotizing. Perhaps Sarah’s involvement in any sort of repetition put her in a trance state, without benefit of suggestion from the hypnotist. All she had was her inner conflict from which to draw. Hello Dr, Wells