In the primary repression phase, 'it is highly probable that the immediate precipitating causes of primal repressions are quantitative factors such as...the earliest outbreaks of anxiety, which are of a very intense kind'.
1 A neurologist treats brain and nervous system disorders that may contribute to sleep problems.  An otolaryngologist treats ear, nose, and throat conditions. This doctor may evaluate snoring and other breathing problems associated with sleep disorders.
Sleep studies help doctors diagnose sleep disorders such as sleep apnea, periodic limb movement disorder, narcolepsy, restless legs syndrome, insomnia, and nighttime behaviors like sleepwalking and REM sleep behavior disorder.