Yes, anxiety is one of the most common causes of insomnia. Not just difficulty falling asleep, but the full range: trouble getting to sleep, waking repeatedly through the night, early morning awakening, and the exhausted-but-wired feeling that comes from lying awake while your mind races. If you have insomnia and anxiety, they are almost certainly maintaining each other.
Sleep requires a shift from sympathetic nervous system dominance, which anxiety maintains, to parasympathetic dominance. Heart rate needs to drop, body temperature needs to lower slightly, the brain needs to shift from active processing toward the slower waves of early sleep. Anxiety does the opposite of all of these. The result is lying in bed physiologically incapable of sleeping, not because something is wrong with your sleep system, but because the anxiety system is overriding it. The body is tired. The nervous system is not.
At sleep onset, the quiet and stillness of bedtime remove the distractions that were managing anxiety during the day, and worry rushes in. During sleep maintenance, anxiety increases micro-arousals through the night, and each awakening is an opportunity for anxiety to become active and prevent return to sleep. Early morning awakening: the cortisol awakening response, which begins rising around 3 to 5am, is amplified in anxious people, producing the 4am wide-awake-with-dread experience. And anxiety reduces the proportion of deep, restorative slow-wave sleep, so you can sleep eight hours and wake exhausted.
Once insomnia is established, it creates its own anxiety: anxiety about sleep. Will I sleep tonight? What if I cannot sleep? What will tomorrow be like if I am exhausted? This sleep anxiety adds a second layer. The anxiety about sleep makes sleep more difficult, which confirms the sleep anxiety, which makes sleep even more difficult. Sleep anxiety is one of the most powerful insomnia-maintaining mechanisms because the bedroom itself and the act of trying to sleep become anxiety-provoking.
Standard sleep hygiene advice is often unhelpful for anxiety-related insomnia on its own. This is not because the advice is wrong. It is because anxiety insomnia is driven by physiological arousal and conditioned associations that sleep hygiene does not directly address. CBT-I is more effective than sleep hygiene alone because it directly addresses the conditioned arousal, the catastrophic sleep beliefs, and the sleep restriction that consolidates fragmented sleep. If you have been following sleep hygiene advice for months without improvement, CBT-I is the next step. The stopping anxious thoughts at night article covers the thought techniques that work in the moment.
CBT for insomnia has stronger long-term evidence than sleep medication and is recommended as the first-line treatment for chronic insomnia by most sleep medicine organisations. Sleep restriction temporarily reduces time in bed to match actual sleep time, consolidating sleep and increasing sleep pressure. Stimulus control uses the bed only for sleep, getting out of bed when unable to sleep, breaking the conditioned arousal between bed and wakefulness. Cognitive restructuring addresses catastrophic thoughts about the consequences of poor sleep, which paradoxically make sleep more difficult by increasing sleep anxiety. The anxiety and sleep cycle article covers the broader relationship in depth.
"You are not failing at sleep. Your anxiety system is keeping you awake. Those are different problems with different solutions."