Sources & Key Research — Depression
Statistics
- Australian Bureau of Statistics (2023). National Study of Mental Health and Wellbeing, 2020-2022. Read the study.
Research and guidelines
- 1. Rock PL, et al. (2014). Cognitive impairment in depression: a systematic review and meta-analysis. Psychological Medicine. Three authors were employed by Cambridge Cognition, which makes the test battery used. Moderate difficulties with attention, memory and planning in depression, some persisting after mood improves. Read the study.
- 2. Noetel M, et al. (2024). Effect of exercise for depression: systematic review and network meta-analysis of randomised controlled trials. BMJ. 218 trials: walking or jogging, yoga and strength training reduced depression; yoga and strength training were the easiest to stick with. Confidence in the evidence was low to very low. Read the study.
- 3. Cipriani A, et al. (2018). Comparative efficacy and acceptability of 21 antidepressant drugs for the acute treatment of adults with major depressive disorder: a systematic review and network meta-analysis. The Lancet. 522 trials: all 21 antidepressants worked better than placebo in the short term. Certainty of much of the evidence rated moderate to very low. Read the study32802-7)
- 4. Masdrakis VG, et al. (2023). Apathy associated with antidepressant drugs: a systematic review. Acta Neuropsychiatrica. Emotional blunting is reported often, especially with SSRIs. Rates vary widely between studies; it appears dose-related and usually eases when the dose is reduced. Read the study.
- 5. McIntyre RS, et al. (2023). Treatment-resistant depression: definition, prevalence, detection, management, and investigational interventions. World Psychiatry. Expert review: at least 30% of people with depression meet the definition of treatment-resistant depression (not enough response to two antidepressants). Ketamine, esketamine, TMS and ECT described as established treatments. Read the study.
- 6. Henssler J, et al. (2024). Incidence of antidepressant discontinuation symptoms: a systematic review and meta-analysis. The Lancet Psychiatry. 79 studies: once placebo effects were accounted for, about one in six to seven people had withdrawal symptoms; severe symptoms were uncommon. Read the study00133-0)
- 7. Moncrieff J, et al. (2025). Evidence on antidepressant withdrawal: an appraisal and reanalysis of a recent systematic review. Psychological Medicine. Reanalysis using only studies that measured withdrawal systematically: about half of people had withdrawal symptoms. Read the study.
- 8. Medicine Today (2025). A ketamine nasal spray now subsidised for treatment-resistant depression. Esketamine nasal spray approved by the TGA in 2021 and PBS-listed from May 2025 for treatment-resistant depression, given in a registered facility under supervision. Read the article.
- 9. Therapeutic Goods Administration. MDMA and psilocybin. Since 1 July 2023, TGA-authorised psychiatrists can prescribe psilocybin for treatment-resistant depression and MDMA for PTSD. Read more.
- 10. Metaxa AM, Clarke M (2024). Efficacy of psilocybin for treating symptoms of depression: systematic review and meta-analysis. BMJ. Independent review of 7 trials (436 people): psilocybin reduced depression significantly more than comparison treatments; certainty rated moderate. Read the study.
- 11. Hsu TW, et al. (2024). Comparative oral monotherapy of psilocybin, LSD, MDMA, ayahuasca, and escitalopram for depressive symptoms: systematic review and Bayesian network meta-analysis. BMJ. After accounting for blinding problems, high-dose psilocybin still helped, but the effect was smaller. Read the study.
- 12. Goodwin GM, et al. (2022). Single-dose psilocybin for a treatment-resistant episode of major depression. New England Journal of Medicine. Funded by COMPASS Pathways. 233 adults with treatment-resistant depression: 25 mg reduced depression more than 1 mg at three weeks; less clear at twelve weeks; side effects common; suicidal thoughts or self-harm occurred in every group. Several authors work for or advise the funder. Read the study.
- 13. COMPASS Pathways (7 July 2026). Six-month data from second phase 3 trial. Company press release; not peer reviewed. Reports two phase 3 trials (258 and 581 people) met their main goals, with benefits lasting at least six months. US approval applied for. Read the press release.
