Insomnia is not evenly distributed. It is more common in women than in men, and it does not arrive at random - it clusters around the points where sleep is disrupted from the outside and then keeps going after the disruption has passed.
That last part is the bit that gets missed. A newborn wakes you at 2am for months, and by the time she is sleeping through, you are not. Hot flashes wake you at 3am through perimenopause, and then the flashes settle down and the waking does not. In both cases something external started it, and something behavioral is now maintaining it - which is exactly the situation the behavioral approach was built for.
What that means practically is that the standard protocol usually has to be adapted rather than abandoned. Sleep restriction as it is written assumes you control your nights. A woman four months postpartum does not. The published trial that tested CBT-I in pregnancy and the postpartum year modified the protocol rather than dropping it, and never prescribed a window shorter than five and a half hours.
These articles cover what is different, what the research actually supports, and where the honest answer is that a sleep program is the wrong tool and you need to be seen by a clinician instead.
