Increase in cortisol awakening response after two weeks of self-instruction for good sleep

There is growing evidence suggesting that the magnitude of cortisol awaking response (CAR), which is characterized by a profound increase of salivary cortisol secretion after awakening, plausibly reflects the level of a chronic stress, social stress, anxiety, etc. In this study the alternation of CAR at the start and at the end of two weeks session of self-instruction for good sleep was investigated; by which we anticipated that the self-instruction for good sleep would bring-forth a positive affection for the participants, and would result in decline of cortisol awakening response (CAR). Nevertheless, as a result unexpectedly, subjects did not change their sleep and dietary habits along with the instruction, moreover the increased CAR was observed. This result implies that the suggestion of an impractical instruction would solely be taken as a stressful task for participants, even though they know that it is effective to improve their sleep. On the contrary, if one develops an instruction with practicable indication for daily life, it is highly possible to observe a positive effect of the instruction on CAR