Body: the physical causes that can look like a psychiatric problem
When someone comes to us feeling flat, anxious, scattered, or exhausted, the fastest thing to do is name it and prescribe for it. The better thing to do is ask what is driving it. A surprising share of what looks like a psychiatric problem has a physical contributor sitting underneath it, and if that piece is missed, the medication either does less than it should or gets blamed for not working.
This is the first of the three pillars we look at in every evaluation at Better Place Now. Here is what the research says.
Medical problems can show up first as mood
A systematic review in Psychotherapy and Psychosomatics found that depression, and less often anxiety or irritability, can be the earliest sign of a medical illness, including thyroid and parathyroid disease, Cushing's syndrome, some cancers, and heart disease. The authors' warning was to clinicians: a picture that looks purely psychiatric still deserves a medical workup.
Thyroid is the classic example. A meta-analysis of 15 studies and roughly 240,000 people found that an overactive thyroid raised the odds of clinical depression by about two thirds, and a large Mayo Clinic cohort of 29,000 patients found the same link between low TSH and depression. Anxiety and thyroid disorders travel together often enough that routine thyroid screening in anxiety is a standard recommendation.
Sleep is usually the first thing we explore
Poor sleep looks like depression. It also looks like anxiety and ADHD. The research is unusually clear here: treating insomnia directly improves mood, not just sleep. A 2024 meta-analysis of 19 trials and 4,808 people with major depression found that cognitive behavioral therapy for insomnia (CBT-I) more than doubled the odds of a depression response, raising it from 17 percent with usual care to 32 percent. Follow-up studies show the benefit holds for at least a year. For people with PTSD or alcohol problems and insomnia, the effect of treating the sleep is even larger.
That is why sleep comes up in the first ten minutes of an evaluation, and why we will often assess and address it before adding or changing a medication.
Nutrition and vitamin levels
In a 2025 study of 1,003 people with serious mental illness, deficiencies in vitamin D, folate, and B12 were common across every diagnosis and were tied to more severe symptoms and worse day-to-day function. Vitamin D deficiency roughly doubled the odds of significant depressive symptoms. An umbrella review of ten meta-analyses found that vitamin D supplementation modestly reduces depressive symptoms, with the strongest effect in people who are actually low or already depressed, and a large JAMA trial found it does not prevent depression in people who are not deficient. The practical lesson: check when it matters, correct what is low, and do not expect a supplement to replace treatment.
Inflammation
About a third of people with depression have low-grade inflammation on a common blood test (C-reactive protein). Reviews in 2022 and 2025 describe this as a distinct subtype, marked by low energy, poor sleep, appetite changes, and a weaker response to standard antidepressants. Knowing that up front changes how we choose and sequence treatment, and it makes lifestyle work like sleep, movement, and food part of the medical plan rather than an afterthought.
The gut
The gut-brain connection is real and still being worked out. Changes in gut bacteria are consistently associated with depression, and probiotics show a meaningful benefit when added to an antidepressant, but not as a replacement for one. We treat gut health as one more input, mostly through food, and we are careful not to oversell it.
The medications you already take
The other physical cause we always check is the medication list itself. Six years on inpatient psychiatric units taught Dr. Justin that many people arrive on a long list of medications that no one has stepped back to review as a whole. Every medication you take gets a reason, and if it no longer earns its place, we talk about it.
What this means for you
Every one of these findings describes a group of people, not you. Whether poor sleep is driving your symptoms or your symptoms are driving your sleep, whether a lab result matters or is a red herring, whether a medication on your list still earns its place: those are questions that take a full hour and your whole history to answer. That is the first thing we sort out at your first visit.
This is how a first visit at Better Place Now works. A full hour, by video anywhere in Arizona or in person by appointment, that looks at body, mind, and lifestyle before any medication decision. Request an appointment or call 480-660-2160.
References
This article summarizes peer-reviewed research. Ask about any of these at your visit.
- Cosci, F., Fava, G. A., & Sonino, N. (2014). Mood and anxiety disorders as early manifestations of medical illness: A systematic review. Psychotherapy and Psychosomatics, 84(1), 22-29.
- Bode, H., Ivens, B., Bschor, T., Schwarzer, G., Henssler, J., & Baethge, C. (2022). Hyperthyroidism and clinical depression: A systematic review and meta-analysis. Translational Psychiatry, 12, 362.
- Kumar, R., et al. (2023). The association between thyroid stimulating hormone and depression: A historical cohort study. Mayo Clinic Proceedings, 98(7), 1009-1020.
- Fischer, S., & Ehlert, U. (2018). Hypothalamic-pituitary-thyroid (HPT) axis functioning in anxiety disorders: A systematic review. Depression and Anxiety, 35(1), 98-110.
- Furukawa, Y., et al. (2024). Cognitive behavioral therapy for insomnia to treat major depressive disorder with comorbid insomnia: A systematic review and meta-analysis. Journal of Affective Disorders, 367, 359-366.
- Fiori, V., et al. (2026). Long-term efficacy of cognitive behavioural therapy for insomnia (CBT-I) on depressive symptoms: A systematic review and meta-analysis of randomised controlled trials. Sleep Medicine Reviews.
- Hertenstein, E., et al. (2022). Cognitive behavioral therapy for insomnia in patients with mental disorders and comorbid insomnia: A systematic review and meta-analysis. Sleep Medicine Reviews, 62, 101597.
- Faugere, M., et al. (2025). Vitamin D, B9, and B12 deficiencies as key drivers of clinical severity and metabolic comorbidities in major psychiatric disorders. Nutrients, 17(7).
- Musazadeh, V., et al. (2022). Vitamin D protects against depression: Evidence from an umbrella meta-analysis on interventional and observational meta-analyses. Pharmacological Research, 187, 106605.
- Okereke, O. I., et al. (2020). Effect of long-term vitamin D3 supplementation vs placebo on risk of depression or clinically relevant depressive symptoms and on change in mood scores: A randomized clinical trial. JAMA, 324(5), 471-480.
- Orsolini, L., et al. (2022). C-reactive protein as a biomarker for major depressive disorder? International Journal of Molecular Sciences, 23(3), 1616.
- Wessa, C., et al. (2025). Current evidence on immune-driven depression. Current Opinion in Psychiatry.
- Nikolova, V. L., Cleare, A. J., Young, A. H., & Stone, J. M. (2021). Updated review and meta-analysis of probiotics for the treatment of clinical depression: Adjunctive vs. stand-alone treatment. Journal of Clinical Medicine, 10(4), 647.
This article is general health information from Better Place Now and is not medical advice for any individual. Research findings describe averages across groups of people; what is right for you depends on your history and a conversation with your clinician. Do not start, stop, or change a medication or supplement based on this article. If you are in crisis, call or text 988.