Meditation therapy is “a method of relaxation and consciousness expansion by focusing on a mantra or a keyword, sound, or image while eliminating outside stimuli from one’s awareness” (Mosby’s Medical Dictionary, 2009).
There are many types of meditation. Examples include mindfulness, body scan, loving-kindness, walking, Zen, mantra, and transcendental meditations. They can be further categorized into insight or calming and guided or unguided. In the world of meditation, there is an approach for everyone.

Each type of meditation has a few things in common: choosing a quiet spot, finding a comfortable posture, and focusing your attention while remaining open (National Center for Complementary and Integrative Health, n.d.).

The duration of meditation practice is as short as one minute to several hours. There also is not a “right” or “only” way to practice. It is as diverse as the people who practice it.

Research and Studies
Several studies are touting the benefits of meditation (NCCIH, n.d.). The degree to which a practice helps with various ailments has come into question. The primary issues have been small sample sizes and weak experimental design.

Goyal and colleagues (2014) conducted a review of 47 trials in 3,515 participants. The researchers found:

Mindfulness meditation programs improve anxiety, depression, and pain at eight weeks and 3-6 months. They cite “moderate evidence” for these improvements.
Low evidence for improved stress/distress and mental health-related quality of life.
Low-to-no evidence of any effect on positive mood, attention, substance use, eating habits, sleep, or weight.
No evidence that meditation programs were better than any active treatment (drugs, exercise, behavioral therapies.)
The authors point out that the studies up to June 2013 did not typically specify the level of expertise of the instructors, the amount of training patients received, or the amount of at-home practice patients did (Goyal et al., 2014).

Studies since their review have found connections between:

Relaxation response training and reduced blood pressure (Bhasin et al., 2018). Note: This study did not include a control group of non-meditators.
Mindfulness training and reduced cravings to smoke (Elwafi, Witkiewitz, Mallik, Thornhill, & Brewer, 2013).
MBSR and CBT training and reduced chronic low back pain. Both were equally effective and resulted in “greater improvement in back pain and functional limitations at 26 weeks” when compared to the person’s regular care routine (Cherkin et al., 2016).
Compassionate responses to another person’s suffering increase among meditation practitioners who have practiced for eight weeks (Condon, Desbordes, Miller, & DeSteno, 2013).
Mindfulness meditation and alleviation of insomnia when compared to an eight-week self-monitoring condition (Ong et al., 2014).

6 Proven Benefits
To say something is “proven” in scientific terms is almost impossible. Social science researchers hesitate to say “x causes y.” They speak in terms of confidence intervals (CIs). The Association for Psychological Science has a fabulous article explaining this topic (Kalinowski, 2010).

Researchers use the term correlation when describing their results. This means that they have found a connection or no connection between the variables in question. For example, one might find that an 8-week mindfulness meditation training negatively correlated with a decrease in insomnia. As the person continued to use mindfulness meditation, their experience of insomnia lessened.

Does this mean that there are no “proven” effects of using meditation therapy? As the prior section indicated, the research is promising.

Here are six more studies:

The amygdala changes after two months of meditation training. Desbordes and colleagues (2012) found that there is less activation in this area after learning meditation.
Meditation has a stronger effect than relaxation training to reduce smoking and cravings (Tang, Tang, & Posner, 2013).
Ramsburg and Youmans (2014) found that meditation improves the retention of information. In their experiments, college students received brief meditation training or rest. Then they listened to a lecture followed by a quiz. Students who received meditation training retained more information. Unaffected variables included mood, relaxation, and class interest.
A 2015 study by Ching, Koo, Tsai, and Chen found that a semester-long mindfulness course improved learning effectiveness. It also enhanced participants’ attention and memory.
Loving-kindness meditation reduces implicit bias against blacks and homeless people (Kang, Gray, & Dovidio, 2013). The researchers compared this result against a loving-kindness discussion group and a waitlisted group.
Goldin, Ziv, Jazaieri, Hahn, and Gross (2013) compared MBSR to an aerobic exercise stress reduction program. They found that “meditation practice was associated with decreases in negative emotion and social anxiety symptom severity and increases in attention-related parietal cortex neural responses when implementing attention regulation of negative self-beliefs.”