Yes I keep hearing this too. It's also hard to know if the symptoms are caused by the oestrogen surges as they rise up or plummet down. My adrenaline rushes seemed to start right at the end of the cycle when everything fell (but then carried on as oestrogen rose in first half of cycle).
Also oestrogen replacement isn't necessarily just to top up but to trick the brain into stopping over production as it can now sense there is enough. This may then stop the volatile surges.
In more direct terms, high oestrogen over stimulates leading to anxiety and high progesterone over sedates leading to depression, with the low of each surge triggering the opposite. However, depression can mean different things to different people where the true clinical state is one of numbness and 'what's the point' demotivation as opposed to the over emotional state of anxiety and fearful demotivation. You can never technically feel them both at the same time but it's common for depression to set in after a long period of anxiety as your brain attempts to protect you from the high emotional state.
Hormone-wise though the surges can put you on an emotional roller coaster where you feel every emotion you've ever encountered within a few hours!