The word parasomnia literally means around sleep, and refers to undesirable, abnormal skeletal muscle activity, behaviors, or emotional–perceptual events that occur during sleep.

Parasomnias may happen at sleep onset, during sleep, during transition between stages of sleep, or when going from sleep to wakefulness.

Parasomnias often cause psychological distress.

  • The unusual nature of experiences can lead to patients being misdiagnosed with other psychiatric disorders.
  • This has huge consequences in terms of treatment and stigma.
  • Parasomnias may be the presenting feature of a psychiatric disorder (e.g. nocturnal bulimia nervosa).
  • Very rarely, parasomnias may manifest as sleep-related violence, which becomes the domain of forensic psychiatry.


There are a variety of different approaches to classifying parasomnias. The ICSD-2 uses the stage of sleep in which the experience occurs, but it is much simpler to consider parasomnias in two categories:

  1. Symptoms due to a primary disorder of sleep itself
  2. Symptoms during sleep which are secondary to an underlying medical or psychiatric condition.

The main types of parasomnias are outlined in Table 28.8. Assessment Polysomnography with audio-visual recording is the gold standard diagnostic tool. It picks up abnormal motor and brain activity during sleep, which can be linked to motor activities and behaviour seen on the video.


The main symptoms of sleep-talking includes:

  • Mumbling
  • Utterances
  • Calling out
  • Talking-out-loud
  • Moaning
  • Whispering


HYOSCYAMUS NIGER:  Confess themselves loudly during sleep. Laugh during sleep. Child sobs and cries in sleep without waking. Sleep with convulsions and involuntary movements of limbs.  

KALI CARBONICUM: Drowsy after eating. Falls asleep while eating. Talks in sleep. Awakes at about 2 a.m. to 4 a.m. with nearly all complaints. Yawns with headache.

LACHESIS: Children toss about moaning in sleep. Sudden startling when falling to asleep. Frightful dreams of snake. Sleeps into aggravation.

NUX VOMICA: Weeping and talking during sleep. Cannot sleep after 3 a.m. until towards morning. Nightmares. Dreams,  anxious, pursued by animals, dogs, and cats, amorous. Ailments from too much of mental strain, over study, drug abuse, over use of stimulants like tea, coffee, and alcohol.

PULSATILLA NIGRICANS: Lies with hands over head or crossed on abdomen and feet drawn up. Chattering in sleep. Talks, whines, or screams during sleep. Restless. Tosses. Dreams confused, frightful.