Low testosterone and depression share many of their symptoms in men: flat mood, no drive, broken sleep, brain fog. The Endocrine Society’s clinical guideline lists versions of all four as symptoms of testosterone deficiency. That overlap is why clinicians treat one for years while the other never comes up. Testosterone doesn’t treat PTSD and it isn’t a replacement for therapy. But when a man is doing everything right and still isn’t getting better, one normal testosterone result shouldn’t be the reason you stop looking. Related episode: Ep 59 on testosterone and your patients’ mental health.
Why does a patient who’s doing everything right still feel terrible?
You know this patient. He’s in therapy and he goes, he does the homework, and he still tells you he feels flat and wired and exhausted at the same time.
His labs look fine. So mental health takes the blame for all of it, and testosterone never enters the conversation.
That was Garrett. Eighteen years in law enforcement, every one of them on night shift. A stack of head injuries from martial arts, college sports, and police work. And a level of trauma most of us will never see up close.
He spent four years in therapy for PTSD before he came to see me. It helped, and he’ll tell you he might not be here without it. He still didn’t feel right.
Here’s what gets me about his case. A couple of years before we met, he’d already done the thing we’d want any patient to do. He felt like he had nothing left in the tank, suspected his testosterone, and asked his primary care provider about it. He got a testosterone test. His provider told him he was fine and sent him home, and that closed the door for years.
What happens when a normal result ends the conversation?
Nobody explained the difference between free and total testosterone. Nobody asked why a man with eighteen years of nights and a history of head trauma might be running low. One number settled the question, so no one looked again.
I want to sit with this part, because it’s the part we control. Garrett wasn’t passive. He noticed something was wrong, named the right hormone, and asked. He advocated for himself inside a system that wasn’t built to hear it. The gap in his care wasn’t his effort.
It was what happened on the other side of the desk.
When we dismiss the question out of habit, we become the next closed door.
Can low testosterone cause depression?
Low testosterone produces a picture that is hard to tell apart from depression, and treating it moves depressive symptoms. A meta-analysis of 27 randomized, placebo-controlled trials covered 1,890 men. Testosterone treatment was associated with a significant reduction in depressive symptoms, with the clearest effect at higher doses.
Testosterone supports dopamine signaling. When it falls, what you see looks like a mood disorder. This is why I teach that depression often presents as a symptom before it becomes a diagnosis. Something upstream is usually driving it. Related reading: hormones and depression: why SSRIs are not the full answer.
I want to be careful here, because the people who oversell this do real damage to those of us trying to practice carefully. Testosterone didn’t replace Garrett’s PTSD treatment. What I’m saying is narrower. If you work up a stuck patient and never look at testosterone, you may have left part of the picture on the table.
What are the symptoms of low testosterone in men?
The symptoms that bring men in are rarely physical first. The Endocrine Society lists depressed mood among the symptoms of testosterone deficiency, alongside decreased energy and motivation, poor concentration and memory, and sleep disturbance.
Read that list again and notice how much of it would get you a depression screen in most primary care offices. That’s the whole problem in one paragraph.
Ask most men what they’d miss first if you took their testosterone away tomorrow. They won’t say the gym. They’ll name the clarity, the confidence, and the ability to sleep: the things that let them feel like themselves.
How does head trauma affect testosterone?
Here’s how I read Garrett’s case. Repeated head injuries left inflammation that started acute and became chronic. Add eighteen years of nights, PTSD that broke up whatever sleep he did get, and almost no recovery. The signaling between his brain and his testes stopped working well enough to make the testosterone he needed.
That pattern isn’t rare. A systematic review of 19 studies looked at the chronic phase after traumatic brain injury. More than a quarter of patients had some degree of pituitary dysfunction. Repeated mild hits count too. In retired professional football players with poor quality of life, nearly one in four had a pituitary hormone deficiency, and 9 percent were hypogonadal.
The stress side of the story runs through cortisol. Chronically elevated cortisol suppresses testosterone, which we cover in cortisol and hormones.
What did treating Garrett involve?
When we ran his labs, Garrett’s testosterone was lower than you’d expect in a 75-year-old man. His vitamin D and B vitamins were deeply low. He had no fuel left in the tank.
B vitamins are cofactors the mitochondria need to make energy. A brain short on energy has a hard time regulating mood and sleep, no matter how hard the patient works in therapy.
Treating him meant treating all of it at once: testosterone, micronutrients, and the therapy he was already doing. We started testosterone at a low dose and adjusted from there. The goal was never the gym. We were trying to get Garrett back.
The first few weeks were slower than he expected. Around two to three weeks in, his head felt clearer, even though his energy hadn’t changed. Once we adjusted the dose, he started to feel some hope. By about six months, his energy had come back, and so had his sex drive.
He credits all of it together: the testosterone, the vitamins, and the therapy. No single lever, pulled in isolation, carried the result. I’ve seen men start testosterone without doing the rest of the work, and when it didn’t fix everything, they felt more hopeless than before. TRT was a tool inside Garrett’s plan. Related reading: functional medicine and better hormone care: a root-cause approach.
On safety, see is testosterone therapy safe for your patients. On benefits, see the hidden benefits of testosterone replacement therapy.
How are testosterone and sleep connected?
For Garrett, sleep is where the change showed up first, and it’s the part he talks about most.
For years he had nightmares about children dying, and then about his own son. It got to the point where he feared going to sleep at all. With testosterone and the vitamin replacement, the nightmares came less often, then he’d go a month or two without one. Four to five years in, he hasn’t had one of the bad ones in about a year.
The physiology runs in both directions. The majority of a man’s daily testosterone release happens during sleep. One week of five-hour nights lowered daytime testosterone by 10 to 15 percent in healthy young men. The nightly rise ties to the first REM period, and fragmented sleep disrupts it. Now picture eighteen years of night shift with PTSD nightmares on top.
For the deeper version of sleep, listen to our episode on mastering your sleep: optimal protocols for sleep recovery. It covers the architecture piece in detail.
Is a normal result always the end of the question?
No. Normal isn’t optimal. Reference ranges come from populations that aren’t healthy, so a result inside the range tells you a man isn’t an outlier. It doesn’t tell you he’s well. Treat the patient, not the number.
The free versus total question that nobody raised with Garrett matters here too. Even the Endocrine Society guideline tells clinicians to measure free testosterone in two situations. One is when total sits near the lower limit of normal. The other is when something may alter SHBG. See free testosterone and SHBG and sex hormone binding globulin.
Who are we missing?
First responders. Veterans. Shift workers. Anyone carrying a load that doesn’t show up on an intake form.
Garrett used alcohol to get to sleep, and the tolerance built. He’ll tell you that himself. I’d argue most of the men sitting around that table after a shift are self-medicating in some way.
He was already asking for help by name, using the right words and pointing at the right hormone. Most of these men aren’t asking to get big. As Garrett put it, they just want to be able to sleep at night.
The takeaway here is to stop treating the question itself as the problem.
Listen to the full conversation with Garrett:
Key takeaways
- A single normal testosterone result isn’t a reason to stop asking why a symptomatic patient feels the way he does.
- Low testosterone and depression share symptoms in men: flat mood, no drive, broken sleep, brain fog.
- Repeated head trauma, chronic stress, and years of broken sleep can disrupt the signaling that drives testosterone production.
- We treated Garrett’s low testosterone alongside his low vitamin D and B vitamins, with the therapy he was already doing.
- Testosterone therapy works alongside therapy and lifestyle. It doesn’t treat PTSD and it doesn’t replace mental health care.
Frequently asked questions
Can low testosterone cause depression?
The symptoms overlap in men, which is why clinicians often treat one and never measure the other. In a meta-analysis of 27 placebo-controlled trials, testosterone treatment was associated with a significant reduction in depressive symptoms. Treating low testosterone isn’t a substitute for mental health care. In a patient who stays stuck despite good treatment, it belongs in the workup.
Does testosterone replacement therapy treat PTSD?
No. In Garrett’s case it worked alongside therapy and lifestyle change, never in place of them.
Does low testosterone affect sleep?
Yes, and the relationship runs both ways. Sleep disturbance is a recognized symptom of testosterone deficiency, and short or broken sleep lowers testosterone. Sleep was the first place Garrett noticed a change.
Why did no one catch this patient’s low testosterone?
His provider tested him once and told him he was fine. Nobody separated free from total, and nobody asked why a man with his history might be low. One normal number ended the conversation.
Should I check testosterone in a man already diagnosed with depression?
If he’s symptomatic and not improving on appropriate treatment, checking is reasonable. A low level doesn’t erase his diagnosis. It may explain part of it, and it gives you something else to treat.
Can head injuries lower testosterone?
Yes. Pituitary dysfunction is common after traumatic brain injury, and researchers have documented hypogonadism in retired football players with repeated mild head injuries. In a patient with a history like Garrett’s, it belongs in the differential.
Does testosterone matter in women?
We cover that separately: why all women should care about testosterone levels. We also have a piece on progesterone and brain health.
Go deeper
The HRT University Master Course builds the reasoning for cases like Garrett’s across six modules, including male HRT and the metabolic foundations underneath it. It carries 30 CE hours and is jointly accredited. See the full course outline. For the prescribing side, see TRT training for providers: how to prescribe with confidence.
References
- Bhasin S, Brito JP, Cunningham GR, et al. Testosterone therapy in men with hypogonadism: an Endocrine Society clinical practice guideline. J Clin Endocrinol Metab. 2018;103(5):1715-1744. https://doi.org/10.1210/jc.2018-00229
- 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. https://doi.org/10.1001/jamapsychiatry.2018.2734
- Schneider HJ, Kreitschmann-Andermahr I, Ghigo E, Stalla GK, Agha A. Hypothalamopituitary dysfunction following traumatic brain injury and aneurysmal subarachnoid hemorrhage: a systematic review. JAMA. 2007;298(12):1429-1438. https://doi.org/10.1001/jama.298.12.1429
- Kelly DF, Chaloner C, Evans D, et al. Prevalence of pituitary hormone dysfunction, metabolic syndrome, and impaired quality of life in retired professional football players: a prospective study. J Neurotrauma. 2014;31(13):1161-1171. https://doi.org/10.1089/neu.2013.3212
- Leproult R, Van Cauter E. Effect of 1 week of sleep restriction on testosterone levels in young healthy men. JAMA. 2011;305(21):2173-2174. https://doi.org/10.1001/jama.2011.710
- Luboshitzky R, Zabari Z, Shen-Orr Z, Herer P, Lavie P. Disruption of the nocturnal testosterone rhythm by sleep fragmentation in normal men. J Clin Endocrinol Metab. 2001;86(3):1134-1139. https://doi.org/10.1210/jcem.86.3.7296
