Why Am I Still So Tired? Differentiating Between Fatigue and Depression

At Stenzel Clinical, we hear this question all the time: “Why am I still so tired?” It’s an honest, worrying question and the answer isn’t always simple. Tiredness can be an ordinary response to a busy life, but when low energy won’t lift, it might point to something deeper: depression, Seasonal Affective Disorder (SAD), or a medical issue that needs attention. Below we’ll walk you through how fatigue and depression overlap, how they differ, what to watch for with SAD and low energy, and practical next steps you can take right now (and when to reach out to a clinician like us).

Fatigue vs. ordinary tiredness: what’s the difference?

We all feel tired sometimes. Ordinary tiredness usually improves after sleep, rest, stress reduction, or a short change in routine. Fatigue especially the kind that people describe when they ask, “Why am I still so tired?” is deeper. It can be a persistent lack of energy, physical and mental heaviness, trouble concentrating, and a sense that even small tasks take huge effort. Fatigue can be caused by lifestyle (poor sleep, not enough exercise), medical problems (like thyroid issues or anemia), medication side effects, or by mental health conditions such as depression.

How depression shows up as tiredness

Depression doesn’t always look like sadness. For many people, the main symptom is low energy: waking up exhausted, sleeping too much (or too little), losing interest in activities, feeling slowed down, and having trouble concentrating or making decisions. Research shows fatigue is one of the most common symptoms of major depressive disorder and often remains even after other symptoms improve. In other words: feeling exhausted isn’t just “in your head” it’s a real, biological symptom that can be part of depression.

Signs that tiredness may be tied to depression include:

• Loss of interest or pleasure in activities you used to enjoy
• Persistent low mood, hopelessness, or increased irritability
• Changes in appetite or sleep that last for weeks
• Slowed thinking, poor concentration, or feelings of worthlessness
• Persistent fatigue that doesn’t get better with rest

If several of these symptoms are present alongside ongoing tiredness, that increases the chance depression is involved.

Where Seasonal Affective Disorder (SAD) fits in

If your tiredness follows the seasons worse in late fall and winter, improving in spring Seasonal Affective Disorder (SAD) could be the reason. SAD is a type of recurrent depression linked to reduced daylight and changes in biological rhythms. Typical features include low mood, increased sleep, carbohydrate cravings and weight gain, social withdrawal, and pronounced low energy. Treatments that help include light therapy, seasonal planning, talk therapy (like CBT), and when needed medication. If you live in the Chicagoland area (where we practice in Wheaton, Naperville, and Geneva), the darker months can trigger this kind of pattern for people who are sensitive to light changes.

Medical and lifestyle causes you should rule out

Before assuming tiredness is depression or SAD, it’s important to rule out common medical or lifestyle causes. These include:

• Sleep problems: sleep apnea, insomnia, shift work, or inconsistent sleep schedules.
• Medical conditions: hypothyroidism, anemia, diabetes, chronic infections, or chronic fatigue syndrome.
• Medication side effects: many medicines (including some blood pressure drugs, antihistamines, and even some antidepressants) can cause drowsiness or low energy.
• Poor nutrition and low activity: low iron, vitamin D deficiency, dehydration, and a sedentary lifestyle all sap energy.
• Stress and burnout: long-term stress can produce ongoing exhaustion that looks like depression.

A routine physical exam and simple blood tests can rule out many of these causes; your provider may also ask about your sleep, diet, medications, and daily routine. Don’t skip the basics sometimes fixing a treatable medical issue or improving sleep restores energy quickly.

How clinicians differentiate fatigue from depression

We use a combination of symptom history, screening tools, and medical testing. Important clues include:

• Timing and persistence: Depression-related fatigue tends to be chronic and accompanied by mood and cognitive symptoms. Ordinary fatigue improves with rest.
• Associated symptoms: Ask yourself do you also feel hopeless, uninterested, or unusually irritable? Are you withdrawing from others? Those signs point toward depression.
• Functional impact: Depression-related fatigue often makes it hard to get through daily routine work, school, or family responsibilities suffer.
• Response to rest: If ample rest, improved sleep, and basic self-care don’t help, that’s a red flag.
• Seasonality: If symptoms reliably return with shorter daylight, consider SAD and discuss light therapy and other season-specific interventions.

When we evaluate you at Stenzel Clinical, we combine symptom screening with a review of medical history and coordinate with primary care for any needed labs or sleep studies. This lets us treat the whole person not just the tiredness.

Practical steps you can try right now

Whether your low energy is fatigue, depression, SAD, or a mix, several low-risk steps often help:

1. Prioritize sleep routine: Aim for consistent bed and wake times, limit screens before bed, and make your bedroom restful.
2. Get morning light: Especially in winter, 20–30 minutes outdoors early in the day (or a recommended lightbox) can reset circadian rhythms. This helps many people with SAD.
3. Move your body: Short walks, gentle aerobic activity, or light strength work can boost energy and mood even 10–20 minutes a day.
4. Check medications and medical causes: Review prescriptions with your doctor; ask about thyroid testing, CBC (for anemia), and vitamin D levels.
5. Keep social connections: Isolation deepens fatigue and depression call a friend or plan a short activity with someone supportive.
6. Use behavioral activation: When low energy makes tasks feel huge, break activities into tiny steps this is an evidence-based strategy we use in therapy to rebuild activity and mood.

Treatment options that work

If lifestyle steps aren’t enough, effective treatments are available:

• Cognitive Behavioral Therapy (CBT): Practical and skill-based, CBT helps change patterns of behavior and thinking that maintain low mood and low energy. Stenzel Clinical offers therapy approaches tailored to each person.
• Light therapy: For SAD, lightboxes used under clinical guidance can dramatically reduce symptoms when used daily in fall/winter.
• Medication: Antidepressants can reduce depressive symptoms and improve energy for many people; however, some medications can cause fatigue as a side effect so careful medication management is important.
• Coordinated care: If medical causes are present (e.g., thyroid disease, sleep apnea), treating the underlying medical issue is often the first step. We partner with primary care and specialists as needed.

When to reach out (and what to expect at Stenzel Clinical)

Reach out to a clinician if:

• Your fatigue has lasted several weeks and isn’t improving with rest or self-care.
• You have other depressive symptoms: persistent low mood, loss of interest, hopelessness, or suicidal thoughts. (If you’re in immediate crisis, call 988 or local emergency services.)
• Your energy level is interfering with work, school, or family life.

At Stenzel Clinical (we serve Wheaton, Naperville, and Geneva and also provide online counseling), we’ll listen carefully, screen for depression and SAD, coordinate medical testing if needed, and work with you to build a treatment plan that fits your life. We aim to restore energy, not just manage symptoms.

Final thoughts

Feeling tired all the time is distressing and it’s common. The good news: most causes are treatable. Fatigue can come from many places sleep, medical conditions, the stress of life, or mental health conditions like depression and SAD. Differentiating between them matters because the right treatment depends on the cause. If you’re asking, “Why am I still so tired?” you’re asking the right question. You don’t have to solve it alone. At Stenzel Clinical, we help people figure out what’s under the tiredness and create clear, manageable steps toward feeling better.

If you want help taking the first step, schedule an appointment with us at Stenzel Clinical. Find a location or book online let’s figure this out together.