What brain mechanisms explain task initiation difficulty?

Task initiation difficulty in ADHD is not about motivation or intention. It’s related to reduced activation in brain networks responsible for starting actions, especially when rewards are delayed. The brain struggles to shift from intention to movement without sufficient stimulation or urgency. This is sometimes called executive friction. Even simple tasks can feel physically heavy to start, while complex or urgent tasks may be easier. Once started, momentum often improves. This is why starting is the hardest part, not doing. It’s a neurobiological bottleneck, not laziness.