Are add and delayed sleep phase syndrome connected?

Not necessarily: Add and delayed sleep phase syndrome (dsps) are not necessarily connected. There is some research however that shows that up to 20% of sleep deprived children have add. Treating the cause of sleep deprivation improves, but does not necessarily resolve the add.

Could be: Sleep problems could make one less attentive. It might look like add but it is really a sleep problem.

Sleep deprivation: Any cause of sleep deprivation, whether sleep apnea, insufficient total sleep, or insomnia associated with delayed sleep phase disorder (dspd) can present with symptoms of add. Keep in mind that with dspd if you are getting 7-8 hours of sleep each night then you're not sleep deprived. Add is actually over diagnosed when in fact it's sleep deprivation causing the symptoms.