Is this depression, or something else?

Low mood, low energy, and a loss of interest can all point to depression, but none of them belongs to depression alone. The same surface can sit on top of several different things: a response to hard circumstances such as grief, burnout, or sustained stress; a physical cause such as a thyroid problem, low iron, or disrupted sleep; or sadness that has simply run heavier and longer than usual without being a disorder. These are difficult to separate from the inside. Telling them apart is what an assessment is for, and the purpose is not to label you, but to match the right kind of help to whatever is actually going on.

Written and reviewed by Matthew Hallam, Registered Psychologist (AHPRA PSY0002471369). 4 min read. Published 28 May 2026. Last reviewed 28 May 2026. Next review 28 May 2027.

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When low mood is a response to something

Sometimes the flatness is not a condition that arrived on its own, but a response to something specific. Grief after a loss. Burnout after a long stretch of overload. The slow weight of stress that has not let up. These can look almost identical to depression from the outside, and they can feel identical from the inside, because the mind and body respond to sustained difficulty in similar ways whatever the source.

What tends to set them apart is that they are tied to a cause, and they often move with it as the circumstance shifts. Grief in particular is not depression, even when it is severe, and most grief does not need treating as an illness. For some people a grief that stays intense and central far longer than expected becomes a recognised condition in its own right, prolonged grief disorder (American Psychiatric Association, 2022), but that is the exception rather than the rule. Sorting a burnout or a heavy stretch of grief from depression is genuinely hard, and it is taken up in detail in the guide on what depression can be mistaken for.

When the cause is physical

Some of what looks like depression is driven, or worsened, by something physical. Fatigue, low mood, poor concentration, and changes to sleep or appetite are the body's general response to a range of medical problems, not only to depression. The diagnostic manuals recognise this directly, with a category for low mood that is the consequence of another medical condition, and they use an underactive thyroid as the worked example (American Psychiatric Association, 2022).

This is the most practical reason to start with a GP. Taking a history and, where it is warranted, arranging tests, which might include checking thyroid function, iron, or vitamin B12, or asking about sleep, is how a treatable physical cause is found rather than missed and read as something else. Current clinical guidance treats attention to physical health as part of looking into low mood, not a separate errand (National Institute for Health and Care Excellence, 2022).

When it might not be a disorder at all

Sometimes the most useful answer is that this is not a disorder at all. Sadness is a normal human response, and it can run deep, sit heavily, and last a while without crossing into depression. A low mood that tracks a hard period, and lifts as things ease, is doing what mood is built to do. What a clinician weighs when telling the two apart is less the low feelings themselves and more how long they last, how widely they spread across different parts of life, and how much they interfere with day-to-day functioning. Where exactly that line sits is its own question, taken up separately.

Why telling these apart matters

The reason all of this matters is that the right response depends on what is actually going on, and these point in different directions. A depressive withdrawal, a thyroid problem, a grief that needs room rather than treatment, and a low that is heavy but still within the ordinary range are not the same thing, and what addresses one will not necessarily touch another. You usually cannot tell which is which from the inside, and you are not meant to. That is what an assessment is for. Seeing a GP, and a psychologist if it is useful, is not about being handed a label. It is about having someone help you work out which of these fits, so that whatever you do next is aimed at the right thing.

This content is general information only. It is not a substitute for individual psychological or medical advice. Reading this does not establish a therapeutic relationship with Equal Psychology or any of their clinicians.