Meditation has become increasingly common in clinical settings over the past 30 years and may offer psychiatric benefits, particularly for substance use disorders. This review critically examines three widely studied meditation modalities—transcendental meditation, Buddhist meditation, and mindfulness-based meditation—describing their backgrounds, techniques, mechanisms of action, and evidence-based clinical applications, with a focus on their emerging role in treating substance use disorders. The review also addresses unique methodological challenges in studying meditation and suggests that meditation may help with substance use disorders through specific mechanisms, though further research is needed.
Hallucinogen persisting perception disorder (HPPD) involves lingering or recurring perceptual phenomena after substance use, which can be mild or severely burdensome. A systematic review of 31 medication studies covering 87 participants found that clonidine, clonazepam, and levetiracetam produced substantial symptom reduction in three observational studies. Among those receiving benzodiazepines, antiepileptics, antidepressants, or alpha agonists, 28% achieved full recovery and 61% partial recovery within a year. Benzodiazepines were ineffective when HPPD was triggered by lysergic acid diethylamide, and risperidone aggravated symptoms. The authors suggest these medications can treat HPPD effectively but call for randomized controlled trials and epidemiological studies.