Sleep and Mental Health: How Treating Insomnia Helps with Depression and Anxiety

When you can’t sleep, your mind doesn’t rest. It races. It replays conversations. It fears tomorrow. For millions of people with depression or anxiety, insomnia isn’t just a side effect-it’s the engine driving the whole cycle. You feel tired, irritable, hopeless. You try to sleep more, but lying there only makes it worse. You start to believe you’ll never sleep well again. And that belief? It keeps you awake.

Insomnia Isn’t Just a Symptom-It’s a Cause

For years, doctors treated insomnia as a side effect of depression or anxiety. If you were sad or anxious, you couldn’t sleep. Fix the mood, and sleep would follow. But research has turned that idea upside down.

A 2025 study in Frontiers in Psychiatry found that people with chronic insomnia are 40 times more likely to develop severe depression than those who sleep well. That’s not correlation. That’s causation. Insomnia doesn’t just come with depression-it makes depression worse, longer, and harder to treat.

The same is true for anxiety. When your brain is stuck in overdrive at night, it rewires itself. Stress hormones like cortisol and CRH stay elevated. Your nervous system stays on high alert. Even if your daytime worries fade, your body still thinks it’s in danger. And that keeps you awake.

The Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) now recognizes insomnia as both a symptom and an independent disorder. That’s a big deal. It means treating sleep isn’t optional-it’s essential.

CBT-I: The Gold Standard That Actually Works

There’s one treatment that stands above all others: Cognitive Behavioral Therapy for Insomnia, or CBT-I. It’s not a pill. It’s not a supplement. It’s a structured, science-backed program that changes how you think about and behave around sleep.

CBT-I isn’t magic. It’s six to eight weekly sessions, each about an hour long. You work with a therapist-or use a digital platform-to tackle four core areas:

• Stimulus control: Your bed is for sleep and sex only. No scrolling, no working, no lying there worrying. If you’re not asleep in 20 minutes, get up. Go sit in another room. Come back only when you’re sleepy.
• Sleep restriction: You’re probably spending too much time in bed. If you only sleep 5 hours a night, you’re not supposed to be in bed for 8. You reduce your time in bed to match your actual sleep. It’s hard at first-you’ll feel exhausted. But over time, your sleep becomes more efficient.
• Relaxation training: Deep breathing, progressive muscle relaxation, mindfulness. These aren’t fluffy wellness tricks. They lower your heart rate, calm your nervous system, and break the cycle of nighttime anxiety.
• Cognitive therapy: You learn to challenge thoughts like “I’ll never sleep again” or “If I don’t sleep tonight, my whole day will be ruined.” These beliefs keep you tense. And tension keeps you awake.

A 2023 review in Sleep journal analyzed 186 studies. The results? CBT-I doesn’t just help you sleep better-it lowers your risk of developing major depression by up to 50%. People who completed CBT-I and achieved full insomnia remission were 83% less likely to develop depression later than those who didn’t improve their sleep.

Why Pills Like Zolpidem Fall Short

You’ve probably heard of Ambien, Lunesta, or other sleep meds. They work-short term. You fall asleep faster. You might even sleep longer.

But here’s the catch: they don’t fix the root problem. They mask it.

A 2025 study in Nature Scientific Reports compared CBT-I to zolpidem. Both improved sleep and mood in the first few weeks. But after six months? The people who did CBT-I stayed better. The people who took pills? Their insomnia and anxiety came back. And often worse.

Why? Because pills don’t change your thoughts. They don’t retrain your brain. They just sedate you. And your brain learns to rely on them. You can’t just quit cold turkey. Withdrawal can make sleep even harder.

CBT-I teaches you to sleep without drugs. And once you learn it, you don’t need to keep doing it forever. The skills stick.

Digital CBT-I: Therapy You Can Access From Your Couch

Finding a CBT-I therapist can be hard. In the U.S., fewer than 5% of psychologists are trained in it. Insurance often doesn’t cover it. Waitlists are months long.

That’s where digital platforms like Sleepio and SHUTi come in. These are online programs built by sleep scientists. They walk you through CBT-I step by step, with videos, interactive tools, and daily check-ins.

One study showed that people using Sleepio had a 57% lower chance of developing moderate-to-severe depression compared to those who just read sleep tips. Another found that 76% of users saw a clinically meaningful drop in insomnia severity.

These platforms aren’t perfect. You still need to do the work. You still have to track your sleep. But they’re far better than nothing. And they’re growing fast. Telehealth CBT-I use jumped 300% between 2019 and 2022.

What Happens When You Don’t Treat Insomnia

Ignoring sleep doesn’t make depression or anxiety go away. It makes them worse.

During the pandemic, Columbia University found that one in three adults had clinical insomnia symptoms. That’s more than double pre-pandemic rates. And those with insomnia were far more likely to report high levels of psychological distress.

Without treatment, insomnia becomes a trap:

• You feel too tired to exercise, so you get less endorphins.
• You skip meals or eat junk because you’re too drained to cook.
• You cancel plans because you’re exhausted.
• You feel guilty for not sleeping, which makes you more anxious.
• The cycle tightens.

And here’s the kicker: treating depression with antidepressants alone doesn’t fix sleep. A 2024 JAMA Psychiatry study found that adding CBT-I to sertraline (a common antidepressant) led to 40% higher remission rates than medication alone.

Barriers to Getting Help

You might be thinking: “This sounds great, but how do I get it?”

The truth? Access is still a huge problem.

- Only 1-2% of people with insomnia get CBT-I.

- Insurance often won’t cover it unless you have a specific diagnosis.

- Many therapists don’t offer it.

- Digital platforms cost money, and not everyone can afford them.

Kaiser Permanente started screening all depression patients for insomnia in 2022. They linked sleep problems directly to care. Result? A 22% drop in depression relapses.

That’s what’s possible when systems change. But until then, you have to be your own advocate.

What You Can Do Right Now

You don’t need to wait for a therapist to start helping your sleep.

Try these steps today:

1. Write down your sleep schedule. What time do you get in bed? What time do you actually fall asleep? What time do you wake up? Do this for a week.
2. Get out of bed if you’re not asleep after 20 minutes. Go to another room. Read a book under dim light. Don’t check your phone.
3. Don’t nap after 3 p.m. Even a 20-minute nap can wreck your nighttime sleep if you have insomnia.
4. Limit caffeine after noon. It stays in your system for 6-8 hours.
5. Try a 5-minute breathing exercise before bed. Breathe in for 4 counts, hold for 4, breathe out for 6. Repeat. This calms your nervous system.

And if you’re ready to go further:

- Look for a CBT-I therapist through the Association for Behavioral and Cognitive Therapies directory.

- Try a digital program like Sleepio or SHUTi. Many offer free trials.

- Ask your doctor to screen you for insomnia. It’s not a normal part of depression or anxiety-it’s a treatable condition.

The Bigger Picture

Sleep isn’t just rest. It’s repair. It’s emotional regulation. It’s memory consolidation. It’s your brain cleaning out the toxins of the day.

When you treat insomnia in someone with depression or anxiety, you’re not just helping them sleep. You’re giving their brain a chance to heal.

And the data is clear: fixing sleep doesn’t just improve mood-it prevents relapse. It saves money. It saves lives.

This isn’t about sleeping more hours. It’s about sleeping better. And that’s something anyone can learn.