SPECIAL REPORT: SLEEP DISORDERS
Insomnia occurs in up to 90% of individuals with symptoms of depression, anxiety, or distress.1 Historically, when insomnia symptoms occurred in the presence of other mental and physical health conditions, the insomnia was viewed as a secondary symptom of the comorbidity (ie, depression causing and maintaining insomnia).2 In many cases, psychiatric symptoms may directly cause and maintain patterns of rumination and negative thinking throughout the night, ultimately leading to the development of insomnia.1,3 However, a substantial body of evidence now suggests that the relationship between insomnia and psychiatric symptoms is more complex, so there is strong rationale for targeted management of sleep problems in the presence of psychiatric symptoms.3-10 In this article, we provide recent evidence on the bidirectional relationship between sleep and psychiatric symptoms to support the targeted assessment and management of comorbid insomnia in mental health settings.
Cognitive behavior therapy for insomnia (CBT-I) is the recommended first-line treatment for insomnia in US and international guidelines.11-14 However, CBT-I is accessed by very few individuals with insomnia disorder,15 including by clients in mental health settings. One of the main barriers is a shortage of clinicians trained in insomnia assessment or the delivery of CBT-I.16
Also In This Special Report
The Overlap in Sleep Problems and Psychiatric Disorders
Ruth Benca, MD, PhD
Beyond the Night: Unraveling the Psychiatric Impact of Sleep Disorders
Michael S.B. Mak, MD, FRCPC, DRCPSC, FCPA, FAASM; Charles Choi, MD; Muhammad A. Siddiqui, BSc; Shizuka Tomatsu, MD; and Matthew J. Gazzellone, MD, FRCPC
What Is a Sleep Disorder? A Harmful Dysfunction Analysis
Jean-Arthur Micoulaud-Franchi, MD, PhD; Christophe Gauld, MD, PhD; Julien Coelho, MD; and Jerome C. Wakefield, PhD, DSW, MSW, MA, BA
Recent Evidence
What is insomnia?
Insomnia diagnostic criteria includes self-reported difficulties falling asleep and/or maintaining sleep on at least 3 nights per week, with associated daytime functional/feeling impairment, in the context of adequate time in bed and opportunity for sleep.17 Insomnia can further be classified as a short-term condition if persisting for less than 3 months (which occurs in approximately 30% to 40% of adults at any given time) or a chronic condition if persisting for at least 3 months (which occurs in approximately 15% of adults at any given time).17 At a disorder level, insomnia and depression also share significant overlap; sleep disturbance is listed among diagnostic criteria for major depressive disorder, and reduced mood is listed among diagnostic criteria for insomnia disorder.17,18
Is it secondary insomnia or comorbid insomnia?
Short-term sleep disturbance can result from many different mental, physical, circadian, environmental, and lifestyle factors.19 However, insomnia symptoms can quickly develop functional independence from the initial causes and become a self-maintaining chronic condition.20 For example, psychiatric symptoms may cause initial sleep disturbances; however, individuals may start spending more time in bed with the aim of acquiring more sleep, resulting in more time awake in bed experiencing frustration or worry about sleep loss, and a learned relationship can develop whereby the bed or bedroom becomes an automatic stimulus for alertness and wakefulness instead of sleep.21 In individuals presenting with insomnia and psychiatric symptoms, it is rarely possible to determine whether the insomnia is a secondary symptom of the mental health condition, a self-maintaining comorbid disorder, or reinforced by a combination of psychiatric and self-maintaining factors.3 For this reason, diagnostic schema have moved away from the term secondary insomnia and instead use the term insomnia disorder, which captures insomnia presenting as an independent or comorbid condition, emphasizing the importance of targeted assessment and management of insomnia as a self-maintaining and treatable condition, regardless of any comorbidity.17
Which comes first, insomnia or psychiatric symptoms?
Epidemiological studies have found that depression can predict the development of insomnia and that insomnia symptoms can predict the development of depression.3 For example, a systematic review and meta-analysis of 21 studies by Baglioni et al found that insomnia was associated with a significantly increased risk of developing depression (OR, 2.6; 95% CI, 2.0-3.4).4 In 2019, Hertenstein et al also reported in a systematic review and meta-analysis that insomnia is associated with increased risks of developing depression (OR, 2.8; 95% CI, 1.6-5.2), anxiety (OR, 3.2; 95% CI, 1.5-6.9), alcohol abuse (OR, 1.4; 95% CI, 1.1-1.7), and psychosis (OR, 1.3; 95% CI, 1.3-1.6).22 These studies highlight the potential bidirectional relationship between sleep and psychiatric symptoms and the importance of sleep disturbance in the prodromal stages or as a causal contributor to mental health decline.
Can insomnia be treated in the presence of psychiatric symptoms?
CBT-I is often delivered over 4 to 8 sessions that aim to identify and gradually treat the psychobehavioral factors that cause and maintain insomnia and any learned relationship between the bedroom environment and an automatic state of alertness and wakefulness.12 Unlike sedative-hypnotic medicines that temporarily target the surface symptoms of insomnia,23 CBT-I aims to target the underlying factors that maintain insomnia and is associated with moderate to large improvements in insomnia symptoms that are sustained over time.24 We recently investigated in 455 individuals presenting to an outpatient CBT-I program whether those with symptoms of depression, anxiety, or stress experienced less benefit from CBT-I vs those without psychiatric symptoms.25 If insomnia is a secondary symptom of psychiatric symptoms, it would be expected that those with more severe psychiatric symptoms would experience less benefit from CBT-I. However, we found that individuals with mild, moderate, and severe levels of depression, anxiety, and stress experienced similar levels of insomnia improvement following CBT-I (Figure).25 These insomnia improvements were also maintained 3 months post treatment.25
Does insomnia treatment improve psychiatric symptoms?
Improving sleep has a positive downstream effect on mental health. Similarly, treating insomnia with CBT-I can improve comorbid psychiatric symptoms.3 For example, meta-analyses have reported moderate to large effects of insomnia treatment on improving depression7,8 and anxiety symptoms in people with insomnia.26 In the aforementioned study of 455 individuals with insomnia treated with CBT-I, we also observed moderate to large and sustained improvements in symptoms of depression, anxiety, and stress after insomnia was treated with CBT-I.25
Does insomnia treatment prevent psychiatric symptoms?
As mentioned previously, insomnia can increase a person’s risk of developing depression4,22 and treating insomnia with CBT-I can improve insomnia and psychiatric symptoms.7,8,26 Therefore, it may be possible to identify and treat insomnia to prevent the development or progression of psychiatric symptoms. That is, early treatment of insomnia may prevent depression. A recent systematic review by Boland et al found 6 research studies that investigated the effect of CBT-I on rates of incident major depressive disorder.27 Four studies found that CBT-I was associated with a reduced incidence of major depressive disorder, and 2 failed to confirm these results in primary analyses (although secondary analyses were consistent with a preventive effect of CBT-I on depression symptoms28).27 Although more research is needed, these are promising findings that indicate that early identification and treatment of sleep problems may be one strategy to prevent the onset and progression of psychiatric symptoms.
Improving the Management of Insomnia in Australia
Despite the established effectiveness of CBT-I and the potential to capitalize on the antidepressant effects of CBT-I in mental health settings, very few individuals with insomnia receive CBT-I.15 For example, in a recent analysis of more than 5 million veterans in the Veterans Health Administration, CBT-I was provided to only 0.2% of patients.29 In Australia, approximately 90% of primary care patients with insomnia are managed with sedative-hypnotic medicines and only 1% are referred for CBT-I.30,31 One of the main barriers is a very limited number of clinicians trained in CBT-I delivery. In a 2020-2021 audit of the number of psychologists in Australia specializing in the management of insomnia, the Australasian Sleep Association identified only 65 sleep psychologists nationally.32
To increase the availability of clinicians trained to deliver CBT-I, the Australasian Sleep Association and Australian Psychological Society have collaborated on an insomnia education and implementation campaign over the last 6 years. The education campaign has resulted in online and print articles on insomnia management in mental health settings,33 webinars on insomnia and CBT-I, the development and promotion of an interactive 6-hour CBT-I education module and downloadable manualized CBT-I program,34 a series of 7 webinars on insomnia management in diverse and comorbid populations, conference attendance for mental health and lifestyle medicine specialists, and the development of a new CBT-I provider directory listing Australian and New Zealand clinicians who have successfully completed training in CBT-I.35 Additional insomnia and CBT-I education is also required for psychiatrists, mental health nurses, and the broader mental health workforce. However, our flagship interactive CBT-I education program can be accessed by any mental health practitioners in Australia and internationally.34
By mid-2026, this education campaign is expected to reach more than 3000 psychologists,36 representing a substantial increase from the 65 recognized sleep psychologists in 2020.32 These education and implementation activities have been funded by a 2021 Australian government grant program awarded to the Australasian Sleep Association, and they are only possible because of a positive and sustained collaboration between the Australasian Sleep Association and Australian Psychological Society and the passion and dedication of many voluntary members and staff. We hope that these education activities will gradually improve the management of sleep problems in Australian mental health settings and that our work may inform similar implementation activities in other locations.
Concluding Thoughts
Insomnia and psychiatric symptoms frequently co-occur in mental health settings. Although insomnia has historically been viewed as a secondary symptom of psychiatric conditions, there is now a substantial body of evidence indicating that sleep and mental health are bidirectionally related. Nonpharmacological treatment of insomnia is effective in the presence of psychiatric symptoms; reduces the severity of preexisting depression, anxiety, and stress; and may reduce a person’s risk of developing psychiatric symptoms in the future. Therefore, mental health practitioners may consider the management of insomnia and sleep problems alongside treatment of psychiatric symptoms.
To increase patient access to CBT-I, it is essential to work collaboratively across the sleep and mental health sector to support more mental health practitioners accessing CBT-I training, resources, and support. Our joint education program has gradually improved recognition of insomnia in Australian psychological settings. We hope that this will improve CBT-I access in the greater community and will be useful in informing similar international implementation and education programs.
Dr Sweetman is a senior program manager at the Australasian Sleep Association and has academic status at Flinders University, Bond University, and the University of Western Australia. Ms Papadopoulos is head of education, training, and assessments at the Australian Psychological Society. Ms Balzer is chief executive officer at the Australasian Sleep Association.
Disclosures: Dr Sweetman is a staff member of the Australasian Sleep Association, reports unrelated research equipment and/or funding support from the Australian Government Department of Health and Aged Care, National Health and Medical Research Council, Medical Research Future Fund, Flinders University, Flinders Foundation, Hospital Research Foundation Group, Big Health, Philips Respironics, Compumedics Limited, Western Australian Suicide Prevention and Resilience Research Centre, American Academy of Sleep Medicine, and Panthera; unrelated commissioned/consultancy work for Australian Doctor Group, Sleep Review magazine, Re-Time Australia, Air Liquide, and Resmed; and unrelated honorarium from the American Academy of Dental Sleep Medicine, Taiwan Society of Sleep Medicine, TMJ Therapy Centres, Cerebra, and the Australian and New Zealand Academy of Orofacial Pain, and is codeveloper of a digital CBT for insomnia program (Bedtime Window).
References
1. Staner L. Comorbidity of insomnia and depression. Sleep Med Rev. 2010;14(1):35-46.
2. Lichstein KL. Secondary insomnia: a myth dismissed. Sleep Med Rev. 2006;10(1):3-5.
3. Sweetman A, Lack L, Van Ryswyk E, et al. Co-occurring depression and insomnia in Australian primary care: recent scientific evidence. Med J Aust. 2021;215(5):230-236.
4. Baglioni C, Battagliese G, Feige B, et al. Insomnia as a predictor of depression: a meta-analytic evaluation of longitudinal epidemiological studies. J Affect Disord. 2011;135(1-3):10-19.
5. Blom K, Jernelöv S, Kraepelien M, et al. Internet treatment addressing either insomnia or depression, for patients with both diagnoses: a randomized trial. Sleep. 2015;38(2):267-277.
6. Cheng P, Kalmbach DA, Tallent G, et al. Depression prevention via digital cognitive behavioral therapy for insomnia: a randomized controlled trial. Sleep. 2019;42(10):zsz150.
7. Cunningham JEA, Shapiro CM. Cognitive behavioural therapy for insomnia (CBT-I) to treat depression: a systematic review. J Psychosom Res. 2018;106:1-12.
8. Gebara MA, Siripong N, DiNapoli EA, et al. Effect of insomnia treatments on depression: a systematic review and meta‐analysis. Depress Anxiety. 2018;35(8):717-731.
9. Li L, Wu C, Gan Y, et al. Insomnia and the risk of depression: a meta-analysis of prospective cohort studies. BMC Psychiatry. 2016;16(1):375.
10. Riemann D, Krone LB, Wulff K, Nissen C. Sleep, insomnia, and depression. Neuropsychopharmacology. 2020;45(1):74-89.
11. Qaseem A, Kansagara D, Forciea MA, et al. Management of chronic insomnia disorder in adults: a clinical practice guideline from the American College of Physicians. Ann Intern Med. 2016;165(2):125-133.
12. Edinger JD, Arnedt JT, Bertisch SM, et al. Behavioral and psychological treatments for chronic insomnia disorder in adults: an American Academy of Sleep Medicine systematic review, meta-analysis, and GRADE assessment. J Clin Sleep Med. 2021;17(2):263-298.
13. Wilson S, Anderson K, Baldwin D, et al. British Association for Psychopharmacology consensus statement on evidence-based treatment of insomnia, parasomnias and circadian rhythm disorders: an update. J Psychopharmacol. 2019;33(8):923-947.
14. Ree M, Junge M, Cunnington D. Australasian Sleep Association position statement regarding the use of psychological/behavioral treatments in the management of insomnia in adults. Sleep Med. 2017;36(suppl 1):S43-S47.
15. Sweetman A, McEvoy RD, Frommer MS, et al. Promoting sustained access to cognitive behavioral therapy for insomnia in Australia: a system-level implementation program. J Clin Sleep Med. 2025;21(2):325-335.
16. Meaklim H, Rehm IC, Monfries M, et al. Wake up psychology! postgraduate psychology students need more sleep and insomnia education. Aust Psychol. 2021:56(6):485-498.
17. International Classification of Sleep Disorders. 3rd ed. American Academy of Sleep Medicine; 2014.
18. American Psychiatric Association. Diagnostic and Statistical Manual of Mental Disorders. 5th ed, text revision. American Psychiatric Association; 2022.
19. Bastien CH, Vallières A, Morin CM. Precipitating factors of insomnia. Behav Sleep Med. 2004;2(1):50-62.
20. Spielman AJ, Caruso LS, Glovinsky PB. A behavioral perspective on insomnia treatment. Psychiatr Clin North Am. 1987;10(4):541-553.
21. Spielman AJ, Saskin P, Thorpy MJ. Treatment of chronic insomnia by restriction of time in bed. Sleep. 1987;10(1):45-56.
22. Hertenstein E, Feige B, Gmeiner T, et al. Insomnia as a predictor of mental disorders: a systematic review and meta-analysis. Sleep Med Rev. 2019;43:96-105.
23. Sweetman A, Putland S, Lack L, et al. The effect of cognitive behavioural therapy for insomnia on sedative-hypnotic use: a narrative review. Sleep Med Rev. 2020;56:101404.
24. van der Zweerde T, Bisdounis L, Kyle SD, et al. Cognitive behavioral therapy for insomnia: a meta-analysis of long-term effects in controlled studies. Sleep Med Rev. 2019;48:101208.
25. Sweetman A, Lovato N, Micic G, et al. Do symptoms of depression, anxiety or stress impair the effectiveness of cognitive behavioral therapy for insomnia? a chart-review of 455 patients with chronic insomnia. Sleep Med. 2020;75:401-410.
26. Belleville G, Cousineau H, Levrier K, St-Pierre-Delorme MÈ. Meta-analytic review of the impact of cognitive-behavior therapy for insomnia on concomitant anxiety. Clin Psychol Rev. 2011;31(4):638-652.
27. Boland EM, Goldschmied JR, Gehrman PR. Does insomnia treatment prevent depression? Sleep. 2023;46(6):zsad104.
28. Christensen H, Batterham PJ, Gosling JA, et al. Effectiveness of an online insomnia program (SHUTi) for prevention of depressive episodes (the GoodNight Study): a randomised controlled trial. Lancet Psychiatry. 2016;3(4):333-341.
29. Pfeiffer PN, Ganoczy D, Zivin K, et al. Guideline-concordant use of cognitive behavioral therapy for insomnia in the Veterans Health Administration. Sleep Health. 2023;9(6):893-896.
30. Miller CB, Valenti L, Harrison CM, et al. Time trends in the family physician management of insomnia: the Australian experience (2000-2015). J Clin Sleep Med. 2017;13(6):785-790.
31. Haycock J, Lack L, Hoon E, et al. O048 help seeking behaviours of Australian adults with insomnia in a community sample. Sleep Adv. 2022;3(suppl 1):A20.
32. Sweetman A, McEvoy RD, Frommer MS, et al. Promoting sustained access to cognitive behavioral therapy for insomnia in Australia: a system-level implementation program. J Clin Sleep Med. 2025;21(2):325-335.
33. Winter S, Meaklim H, Kennedy G, et al. Sleep problems in psychological practice. InPsych. 2022;44.
34. CBT for Insomnia (CBTi) certified skills course. Australian Psychological Society. Accessed April 17, 2025. https://psychology.org.au/event/24371
35. Sleep central: CBTi provider directory. Australasian Sleep Association. Accessed April 17, 2025. https://sleep.org.au/Central/Contents/Clinicians-CBTi.aspx
36. Over 22,000 primary care staff provided sleep education through ASA grants. Australasian Sleep Association. February 5, 2025. Accessed April 17, 2025. https://www.sleep.org.au/Public/News/F-ASA-news/Feb/ASA-grants.aspx
