GAD is excessive, difficult-to-control worry across multiple domains, present more days than not for six months or more, with physical symptoms and real interference. The worries are typically ordinary things: money, health, family, work, whether you offended someone.
The distinguishing feature isn’t their content but their behavior. They drift. Resolve one and another moves into the space, and the state persists regardless of which topic currently occupies it.
The physical half
Frequently the presenting complaint, and frequently investigated for years before anyone mentions anxiety. Muscle tension — jaw, shoulders, neck. Fatigue that sleep doesn’t fix. Restlessness. Difficulty concentrating. Irritability. Disturbed sleep, characteristically difficulty falling asleep because the mind won’t stop.
Chronic muscle tension causes real pain, and headaches and back pain from GAD aren’t imaginary.
What drives it
Intolerance of uncertainty. The best supported mechanism. Not needing things to be good — needing to know. Worry is an attempt to eliminate uncertainty by thinking, and it fails at that while feeling like progress.
Positive beliefs about worry. Most people with GAD believe, somewhere, that worrying helps: it prepares them, it prevents complacency, it means they care, it stops bad things happening by keeping vigilance up. These beliefs are rarely examined and they’re the reason people resist letting go of it.
Worry as avoidance. Verbal worry is oddly flat emotionally compared to imagining a feared outcome vividly. There’s evidence that worry functions partly to avoid the sharper emotional experience underneath — which explains why so much of it is abstract and wordy.
Treatment
CBT is first line, and for GAD specifically it works better when aimed at the mechanism than at the individual worries. That means: examining the beliefs about worry, building tolerance for uncertainty through behavioural experiments, and reducing the checking and reassurance that maintain it.
Stimulus control — postponing worry to a designated period — is a simple technique with surprisingly good evidence.
ACT and metacognitive therapy both have evidence here and both suit people who have already tried to argue with their worries and lost.
Effect sizes in GAD are more modest than in panic or phobia. It’s a chronic condition and treatment usually reduces rather than eliminates it, which is worth knowing so that partial improvement doesn’t read as failure.
The thing to stop doing first
Trying to think your way to certainty. Every worry episode is an attempt to reach a settled conclusion about an unsettled future, and the reason it takes four hours is that the target doesn’t exist.