Dose-Response Effects of Mindfulness Meditation

Inclusion Criteria: * Reside in Australia, with no plans to relocate or travel overseas during the intervention period; * Sufficient comprehension of the English language to complete measures; * Register for an account and agree to the Terms and Conditions of Unforgettable.Me; * If suffering anxious or depressive symptoms of moderate severity (defined by \> 19 on the Patient-Reported Outcomes Measurement Information System \[PROMIS\] Level 2 Anxiety or \> 22 on the PROMIS Level 2 Depression), must agree to continue recommended routine medical treatment for eligible underlying mental and/or physical health conditions or the duration of the study and to seek additional treatment if indicated by deterioration of symptoms; * No or minimal experience with meditation, defined as less than 25 hours over the past 6 months; never attended a multi-day mindfulness course (e.g., Mindfulness-Based Stress Reduction, Vipassana). If 50% of our target sample size has not bee recruited within the first three months of active recruitment, the inclusion criteria will be broadened to include participants with up to 100 hours in the past 6 months. Exclusion Criteria: * Self-reported current or lifetime serious mental illness (e.g., neurodevelopmental, schizophrenia spectrum, bipolar, obsessive-compulsive, trauma-related, dissociative or personality disorder); * Anxious and depressive symptoms in the severe range (defined by \>27 on the PROMIS Level 2 Anxiety or \> 32 on the PROMIS Level 2 Depression); * Psychological distress symptoms in the severe range (Kessler Psychological Distress Scale \[K10\] \>= 30); * Threshold scores on pre-screening and follow-up measures exceeded for Mania, Suicidal Ideation, Psychosis, Repetitive Thoughts \& Behaviors, Dissociation * Moderate alcohol, tobacco, or drug use; * Self-reported diagnosis of neurological condition (e.g., traumatic brain injury, amnesia, epilepsy, stroke, etc.); * Self-reported presence of any serious medical condition (e.g., cancer, thyroid disorder, multiple sclerosis, etc.); * Recent bereavement or major loss; * History of unexplored, untreated traumatic experiences or adverse childhood events.