Psychiatric Evaluation

Medical Conditions That Can Look Like Anxiety, Depression or ADHD

By Dr. Stacey Forbes, DNP, APRN, PMHNP-BC · Updated October 12, 2026

Some physical conditions produce symptoms that look exactly like a psychiatric disorder: the racing heart and dread of anxiety, the flatness and fatigue of depression, the scattered focus of ADHD. NIMH notes that certain medications and medical conditions, such as thyroid disorders, can cause the same symptoms as depression. This guide is organized by what you are feeling rather than by lab test. For each pattern it lists the medical look-alikes worth considering, the clues that point toward the body, and how a careful evaluation sorts them out.

Why look-alikes matter

If a medical condition is driving your symptoms, psychiatric treatment alone may help only partly, or not at all, and the underlying problem continues. If it is one contributor among several, treating it can make everything else work better. And sometimes there is no medical cause, which is useful to know too.

This page is not a list of hidden causes of depression; 8 hidden causes of depression covers that. Nor is it a lab guide; what your psychiatric provider should be testing and 6 lab tests that can change treatment explain the tests. Here the question is narrower: when a symptom pattern looks psychiatric, what else could it be?

When it feels like anxiety

Anxiety is partly a body state: fast heartbeat, shakiness, sweating, poor sleep, a sense of threat. Several medical conditions create the same state from the outside in.

• Overactive thyroid (hyperthyroidism). NIDDK lists nervousness, irritability, trouble sleeping, a rapid or irregular heartbeat, shaky hands, weight loss despite a good appetite, and trouble tolerating heat. Weight loss and heat intolerance alongside “anxiety” are the clues.
• Too much caffeine, or caffeine withdrawal. MedlinePlus lists restlessness, shakiness, insomnia, a fast heart rate and anxiety from too much, and headaches, irritability and trouble concentrating when you cut back suddenly.
• Alcohol withdrawal. Symptoms tend to start within 8 hours after the last drink and include anxiety, irritability, shakiness and nightmares. Morning or “next day” anxiety in someone who drinks most evenings is worth an honest conversation. Severe withdrawal can become life-threatening and needs medical care.
• Low blood sugar. Shaking, sweating, nervousness or anxiety, irritability or confusion, and hunger are typical. It is most common in people with diabetes who take insulin or certain other diabetes medicines, so an “anxiety attack” that eases after eating, in someone on those medicines, points somewhere specific.
• Medicines. Steroids such as prednisone can cause sleeplessness and mood changes, and stimulants can cause jitteriness; any medicine started shortly before the anxiety began is worth mentioning.

For the physical side of real anxiety, see 8 physical symptoms of anxiety. The point is not that body symptoms mean “not anxiety,” but that a new or unusual pattern deserves a medical look.

When it feels like depression

• Underactive thyroid (hypothyroidism). NIDDK lists fatigue, weight gain, trouble tolerating cold, depression and a slowed heart rate among common symptoms. It is more common in women and in people over 60. NIDDK also cautions that fatigue and weight gain are common and do not by themselves mean a thyroid problem; the diagnosis cannot be made from symptoms alone.
• Overactive thyroid in older adults. Counterintuitively, NIDDK notes that in older adults hyperthyroidism is sometimes mistaken for depression or dementia, and may show up as loss of appetite or withdrawal from people.
• Iron-deficiency anemia. NHLBI lists fatigue, dizziness, cold hands and feet, and pale skin. Heavy periods and regular use of anti-inflammatory painkillers are among the causes of blood loss. Exhaustion that looks like depression, in someone with heavy periods, is a reason to check.
• Steroid medicines. MedlinePlus lists extreme changes in mood, personality changes, trouble sleeping and depression among prednisone’s possible effects. Mood changes that began after a course of steroids are worth mentioning even if the course has ended.
• Viral illness. NIMH names viruses alongside thyroid disorders as conditions that can cause depression-like symptoms. Weeks of low mood and fatigue after an infection deserve a medical as well as a psychiatric look.

For how specific medicines affect mood, common psychiatric medication side effects and reviewing several psychiatric medications go further.

When it feels like ADHD or brain fog

Trouble focusing, forgetting things and feeling mentally slow are among the least specific symptoms in medicine. Before concluding it is ADHD, or adding to an existing ADHD plan, an evaluation considers:

• Sleep apnea. MedlinePlus lists daytime sleepiness, morning headaches, forgetfulness, feeling grumpy, impatient or irritable, and depression. NHLBI notes that you may not know you have the nighttime symptoms until someone tells you, and that children with sleep apnea may be overactive and have trouble paying attention in school. Loud snoring, gasping or waking unrefreshed are the clues.
• Low vitamin B12. MedlinePlus lists trouble concentrating, numbness and tingling in the hands and feet, and loss of balance, with confusion, irritability and, in severe cases, psychosis or dementia. Risk is higher with long-term metformin or heartburn medicines, weight-loss surgery, celiac or Crohn’s disease, and a strict vegetarian diet. Nerve damage may become permanent if treatment is delayed, which is why it is worth catching. More in can low vitamin D or B12 affect your mood?.
• Perimenopause. The Office on Women’s Health notes that as many as two-thirds of women going through perimenopause report problems with memory or focus.
• Depression and anxiety themselves. Both impair concentration. Part of an evaluation is sorting which came first.

For a fuller look at ADHD assessment, see what a thorough adult ADHD evaluation includes and ADHD beyond stimulants.

Perimenopause: mood, sleep and focus together

Perimenopause, the transition before the last period, usually starts in the mid- to late 40s and can last two to eight years. The Office on Women’s Health says the risk of depression and anxiety is higher during the time around menopause, possibly from changing hormones, menopausal symptoms, or both. It also lists irritability and crying spells, trouble sleeping through the night, and forgetfulness.

OWH draws a useful line: mood changes are not the same as depression. Irregular periods, hot flashes or night sweats arriving alongside new anxiety or low mood are a reason to consider both. Women who had mood changes around their periods or after giving birth may be more likely to have mood changes now. See hormones and mental health for the integrative angle.

Clues that point toward the body

None of these proves a medical cause. Each is a reason to look.

How an evaluation sorts it out

NIMH describes the basic approach for depression: a provider can rule out medical look-alikes with a physical exam, an interview and lab tests. In practice that means a careful history first (timing, physical symptoms, every medicine and supplement, sleep, alcohol and caffeine), then targeted testing rather than every test at once, then reviewing results together and deciding what to treat first.

In the integrative psychiatric evaluation at Willow & Stone, lab recommendations are made when they are useful and reviewed with you at a follow-up visit. Some findings are best handled by your primary care clinician, such as a suspected thyroid disorder or sleep apnea, which may need a sleep study. The psychiatric side of the plan continues alongside. Finding a physical contributor rarely means the emotional symptoms were imagined; it means there is more than one thing to treat.

Common Questions

Sources & Further Reading

• NIMH — Depression
• NIDDK — Hypothyroidism (Underactive Thyroid)
• NIDDK — Hyperthyroidism (Overactive Thyroid)
• MedlinePlus — Anemia due to B12 deficiency
• MedlinePlus — Obstructive sleep apnea, adults
• Office on Women’s Health — Menopause symptoms and relief

This article is general education, not a diagnosis or advice for your situation. Only a clinician who has evaluated you can diagnose a condition or recommend treatment.