Low Testosterone and Depression: Which One Are You Dealing With?

A man of 44 describes it to his GP as flatness. Not sadness exactly. The things that used to interest him have stopped landing. He is tired in a way that sleep does not fix, he has lost interest in sex, and he cannot concentrate for more than twenty minutes.

He leaves with an antidepressant prescription. No hormones were tested.

Two streets away, another man with the same description reads about low testosterone, orders a private test, comes back at 8.1 nmol/L and concludes he has found his answer. He has not seen a doctor about his mood at all.

Both men may be right. Both may be wrong. What neither has been given is the thing that actually separates these two conditions, and it is not a hormone level.

If you are having thoughts of harming yourself, this article is not the right place to start. Contact your doctor, or a crisis line in your country, today.

Why these two get confused

Look at what low testosterone and depression each produce.

Low testosterone: fatigue, low mood, reduced libido, poor concentration, disturbed sleep, loss of drive, irritability.

Depression: fatigue, low mood, reduced libido, poor concentration, disturbed sleep, loss of drive, irritability.

The lists are close to identical. This is not a coincidence of description. Testosterone acts on brain regions involved in mood and motivation, and the systems overlap.

Which means a symptom list cannot separate them. Neither can a blood test on its own, because a low testosterone result in a depressed man does not establish which came first. The warning signs men ignore covers the symptom side; this article covers what happens when those symptoms have two possible owners.

The relationship is real, and it runs both ways

Men with low testosterone have higher rates of depressive symptoms than men with normal levels. That association is consistent across studies and is not in dispute.

What is in dispute is direction, and there is good evidence for causation in both directions.

Low testosterone contributing to low mood is plausible on mechanism, and men treated for genuine deficiency often report mood improving.

Depression lowering testosterone is equally well supported. Depression disrupts sleep, and most testosterone is produced during deep sleep. It raises cortisol, which suppresses the signal from brain to testes. It reduces activity and often changes eating patterns and body weight. Each of those independently lowers testosterone, and depression frequently produces all of them at once.

Something else causing both is the possibility most often skipped. Obstructive sleep apnoea, chronic illness, alcohol, opioid painkillers and untreated thyroid disease each lower testosterone and each independently worsen mood. What causes low testosterone covers the full list.

A man can arrive at both diagnoses through any of these routes, and the route determines what actually helps.

What the largest trial found

The TRAVERSE trial gave a clearer answer than the observational literature ever could, because it randomised men to testosterone or placebo and measured mood as a defined outcome.

Among 5,204 hypogonadal men, roughly half had depressive symptoms at baseline, most of them mild to moderate, with around one in ten scoring in the severe range. That in itself is worth noting: depressive symptoms are common in men with low testosterone, far more common than most men expect.

The treatment result was modest and specific.

• Mood: small but statistically significant improvement on testosterone compared with placebo
• Energy: same, small but real
• Sleep quality: no significant effect
• Cognition: no significant effect

Those improvements appeared in men with and without significant depressive symptoms at the start.

Read what that says carefully. Correcting a deficiency helps mood a little. It does not fix sleep, it does not sharpen thinking, and the size of the mood effect is nothing like what an effective antidepressant produces in someone with major depression.

The trial investigators made a further point worth repeating: improvements in non-specific symptoms like mood and energy in these men are more likely to reflect correction of hypogonadism than treatment of depression as such.

Testosterone is not an antidepressant

This is the sentence the internet gets wrong most often, and the misunderstanding cuts both ways.

Testosterone therapy is not a treatment for depression. It is not licensed as one, the effect sizes do not support it, and a man with major depression who receives testosterone instead of proper treatment has been failed.

Equally, a man with genuine hypogonadism whose mood symptoms are dismissed as depression, and who is never tested, has also been failed. Both errors are common. Both leave a treatable condition untreated.

The trap worth naming: a man who believes his mood is a hormone problem may put off getting help for months, waiting for a level to come up. Depression is a serious condition. It does not wait politely while a supplement stack is tested.

The medication loop nobody mentions

Here is a genuine complication that catches men in the middle of this.

Several antidepressants, particularly SSRIs, commonly cause sexual side effects, including reduced libido and difficulty with erections. Some evidence also suggests effects on testosterone, though this is less consistent than the sexual side effects themselves.

So a man is treated for depression, his mood improves, and his libido gets worse. He interprets the persisting sexual symptoms as proof of a testosterone problem. Sometimes he is right. Sometimes he is describing a known and often manageable medication effect.

The way out is not to stop the antidepressant. It is to raise it, because dose adjustment, timing or a change of drug are all options a prescriber can consider. Medications that lower libido covers which drugs do this and how often.

Do not stop a prescribed antidepressant on your own. Stopping abruptly causes withdrawal effects and can trigger relapse.

How to work out which you are dealing with

The order matters, and it is not the order most men use.

Get the mood assessed properly first, by a doctor, using a validated tool. Not a website quiz, and not your own reading of yourself. This is the step men skip most, and it is the one that determines everything after it.

Get testosterone measured properly. Two morning samples on separate days, with SHBG, free testosterone, LH and FSH. A single afternoon reading proves nothing. The blood test guide covers what to ask for.

Screen for the shared causes. Thyroid function, ferritin, HbA1c, and specifically sleep apnoea if you snore heavily or wake unrefreshed. Any of these can produce both problems at once.

Look at the timeline. Did the mood change come first, or the physical symptoms? It is not proof, but a man whose libido and energy faded over two years before his mood dropped is telling a different story from a man whose life fell apart in three months.

Treat what is clearly there. If testosterone is genuinely and repeatedly low, correcting it is reasonable and may help mood modestly. If depression is present, it needs treating in its own right. These are not alternatives, and a man can need both.

What to do this week

If your mood has been low for more than two weeks, see a doctor about your mood. That is the whole of the first step, and it is not optional.

If you also have physical symptoms that look hormonal, ask for the hormone panel in the same appointment. Both conversations can happen at once, and they should.

Meanwhile, the things that help both conditions are the same and are worth starting regardless: sleep timing, daylight, regular movement, and reducing alcohol. Why you wake up tired covers sleep, and the alcohol question covers a factor that worsens mood and testosterone simultaneously.

If you want a structured picture of your symptoms to take to that appointment, the free two-minute testosterone test gives you one. It is a starting point for a conversation, not a diagnosis, and it does not assess mood.

Common questions

Does low testosterone cause depression?

It contributes in some men, but the relationship runs both ways. Depression lowers testosterone through disturbed sleep, raised cortisol and reduced activity, and several conditions cause both at once. Low testosterone alone rarely explains major depression.

Will testosterone therapy fix my mood?

Modestly, if you have a genuine deficiency. The largest trial found small but real improvements in mood and energy, with no effect on sleep or cognition. That is not the same as treating depression, and testosterone is not licensed as an antidepressant.

Should I get my testosterone tested if I am depressed?

It is reasonable, particularly with physical symptoms such as low libido, fatigue or loss of morning erections. It should be in addition to a proper mood assessment, not instead of one.

Can antidepressants lower my testosterone?

Sexual side effects including reduced libido are common and well documented with SSRIs. Effects on testosterone itself are less consistent. Either way, this is a conversation with your prescriber, not a reason to stop the medication.

Which should I treat first?

Get both assessed, then treat what is clearly present. If depression is significant, it needs treating in its own right. Waiting for a hormone level to improve while depression goes untreated is the most common mistake here.

Sources: Bhasin S et al., Depressive syndromes in men with hypogonadism in the TRAVERSE trial: response to testosterone-replacement therapy, J Clin Endocrinol Metab 2024;109(7):1814-26 · Walther A, Breidenstein J, Miller R, Association of testosterone treatment with alleviation of depressive symptoms in men: a systematic review and meta-analysis, JAMA Psychiatry 2019;76(1):31-40 · Zarrouf FA et al., Testosterone and depression: systematic review and meta-analysis, J Psychiatr Pract 2009;15(4):289-305 · Leproult R, Van Cauter E, Effect of 1 week of sleep restriction on testosterone levels in young healthy men, JAMA 2011;305(21):2173-4 · Bhasin S et al., Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline, J Clin Endocrinol Metab 2018;103(5):1715-44 · Educational only, not medical advice. If you are struggling with your mood, speak to a doctor.

Keep reading: What causes low testosterone · Warning signs men ignore · Medications that lower libido · Doctor said normal but I still feel tired · Blood test: what to check · Free 2-minute testosterone test