"What's the difference between Transcendental Meditation and mindfulness meditation?" This frequently asked question arises out of the growing popularity of these two mainstream meditation practices. Due to requirements of time and tuition for learning the Transcendental Meditation technique, some people may wonder, "Aren't all meditations basically the same?" Mindfulness practices can be easily learned from a book, online or from a therapist, whereas the TM course involves up to 15 hours of training and can be learned only from a certified instructor. It's no wonder that people often want to compare these meditation techniques.
Although both forms of meditation produce relaxation and practitioners may report some similar benefits—such as inner calm and centeredness, pain management or greater awareness and focus during the day—these techniques differ considerably, both in practice and range of effects as measured by scientific research.
What is mindfulness meditation?
Mindfulness meditation (or guided mindfulness) generally involves watching ones thoughts, the breath or bodily sensations while sitting quietly. Typically, during mindfulness one does not judge or hold on to thoughts or perceptions, but merely observes. Mindfulness is often described as the process of being attentive to ones experiences. This practice of being mindful may also extend into daily activity, as one adheres to dispassionate observation of thoughts and actions in order to be more more fully present in the moment and not overshadowed by passing concerns.  The practice of mindfulness takes place in what psychologists and neuroscientists generally call the waking state of consciousness, different from the sleep or the dream states.
What is the Transcendental Meditation technique?
During the practice of the Transcendental Meditation technique, the mind spontaneously transcends, going beyond the mental activity of waking state to a unique state of restful alertness, called Transcendental Consciousness—a proposed fourth state of consciousness unlike waking, dreaming or sleep. This easy meditation involves using a mantra, or sound without meaning, that has a harmonizing effect on the mind and body, producing deep relaxation and quieter mental activity. Because deeper levels of the mind are more concentrated with energy, creativity and intelligence, ones awareness becomes infused with these qualities as the meditator experiences the inner depths of consciousness.
Meditation and the brain
Over the last several decades, many scientist have become fascinated with researching physiological correlates of the meditative state—studying Tibetan monks, Indian yogis and trained Western meditators as their subjects. One thing has become obvious: different meditation techniques produce different levels of relaxation, change in breath rate, brain function and benefits for mind and body.
For example, recent research on mindfulness meditation recorded a pattern of increased gamma in the rear of the brain, and found no significant changes in alpha activity.  Increased gamma is associated with heightened focus of attention.
Research on the Transcendental Meditation technique has repeatedly shown highly synchronous alpha throughout the entire brain, especially in the pre-frontal cortex.  Heightened alpha is associated with relaxed wakefulness, and increased coherence indicates better overall brain functioning and is correlated with improved learning ability, higher IQ, higher moral reasoning and increased neurological efficiency. This state of coherence is not found in ordinary relaxation or other meditation practices.
Meditation techniques that keep the mind actively attentive in the waking state, as mindfulness-type practices do, have not been found to consistently produce a level of relaxation deeper than ordinary eyes-closed rest—and relaxation is not a primary intention of all meditation practices. Transcendental Meditation is the only meditation found by research to produce a level of rest more than twice as deep as ordinary relaxation, indicated by changes in breath rate, skin resistance and plasma lactate. 
Though meditation can be practiced strictly for health benefits—such as reduction of high blood pressure—the awakening of full human potential, called nirvana or enlightenment, has historically been the goal of many of the venerated traditions of meditation. Fortunately, modern researchers have discovered a scientific basis for identifying higher consciousness—a coherent style of brain functioning and a balanced, more refined state of physiology. Numerous, peer-reviewed studies show that EEG coherence and more harmonious physiological functioning accompany both deep meditation and a continuous state of heightened awareness in activity. Research breakthroughs such as these are raising the field of meditation and personal growth to the evidence-based standards of science.
The mindfulness approach to enlightenment
Many contemporary approaches of mindfulness strive to attain enlightenment by recapitulating the qualities of the enlightened state as a practice in meditation and daily life. Equanimity of mind, being fully present in the moment, and impartially observing ones thoughts are some of the attributes often associated with the state of enlightenment. Many spiritual aspirants believe that consciously striving to maintain these "enlightened" qualities in daily life will lead to total mindfulness or enlightenment.
Enlightenment through Transcendental Meditation
TM practice offers another approach to enlightenment, one that involves simultaneously culturing both mind and body through twice-daily transcending. By alternating morning and evening TM with one's normal, natural daily routine, the inner, silent state of "pure consciousness" becomes stabilized and lived in the midst of one's outer activity. With this approach, there is no conscious attempt to maintain equanimity or detachment during or after meditation. The brain spontaneously becomes habituated to maintain a more orderly, coherent style of functioning, naturally giving rise to inner calm, broader comprehension, increased creativity and self actualization.[ 6] When the physiology gains deep relaxation during TM practice, accumulated stress is dissolved and the whole system becomes more balanced and resilient, able to support the spontaneous growth of higher consciousness in a natural way.
Varying, modern-day interpretations of meditation can account for differences in effectiveness between the many practices. When comparing meditations, whether the Transcendental Meditation technique, Vipassana, Zen, or guided meditation, it is now possible to refer to scientific research on the benefits before committing time to a meditation program. To find research studies on the different meditation practices, one can visit the National Institutes of Health Web site (PubMed).
1. Clinical Psychology: Science and Practice, 10(2), 125-143.
2. Science 167 (1970), Scientific American 226 (1972), American Journal of Physiology 221 (1971), Electroencephalography and Clinical Neurophysiology 35 (1973).
3. Occipital gamma activation during Vipassana meditation, Department of Psychiatry, University of California, San Diego, La Jolla, CA.
4. International Journal of Neuroscience 14: 147–151, 1981.
Revue d’Electroencephalographie et de Neurophysiologie Clinique 4: 445–453, 1974.
5. Hormones and Behavior 10: 54–60, 1978
American Psychologist 42: 879–881, 1987.
6. Hypertension 26: 820–827, 1995
7. Journal of Clinical Psychology 45 (1989), Journal of Clinical of Psychology 33 (1977).
Journal of Social Behavior and Personality (17: 93–121, 2 ,Journal of Social Behavior and Personality (6: 189–248, 1991)