If you have been reading this website you will have picked up (I hope) the critical role that sleeping plays in causing and maintaining depression. Go here for the detail. The bottom line in terms of sleep differences and diagnosis is that depression means waking up exhausted by the attempt while sleeping to dream more than the body is able to. Depression sufferers will normally go to sleep quite quickly, being exhausted and ready for sleep and may indeed sleep uninterrupted through the night, but this sleep will not refresh them.
The contrast with the sleep differences of anxiety sufferers is clear. Yes, they will also have bad sleeping patterns, but they will be different. The problem will not be the exhaustion in the morning – indeed those with anxiety can sometimes wake up reasonably refreshed. No, anxiety means that you cannot quickly get off to sleep. You head is racing with useless “what if” thoughts and projections and so on – all going round and round, like a hamster on a wheel. And so sleep will be delayed and often interrupted and intermittent and rarely restful.
You can understand both of these sleep differences as the two principle failing strategies – to deal with a mind that is out of control and so profoundly terrifying and unsettling.
And there you have it. Depending on their sleep experiences, I will have a clear pointer as to how I will help my clients. For depressions it is about reducing arousal and rumination, to improve sleep and for anxieties it is about dealing with the trauma (that will invariably be there) and then helping to change their relationship with the anxiety.