Thermoregulatory Fear of Harm Mood Disorder: In Depth Exploration of a Unique Juvenile-Onset Phenotype That Provides a Parsimonious Clinical Description of Certain Youths with Highly Comorbid Treatment Refractory Psychiatric Disorders

Abstract

Among aggressive youths with severe mood lability who frequently fail to benefit from mood stabilizers and antipsychotics there is a discrete subtype called ‘Thermoregulatory Fear of Harm Mood Disorder’ (FOH). This disorder is characterized by an underlying thermoregulatory deficit, a specific prodromal sequence and a unique constellation of symptoms. The underlying problem appears to be a deficit in thermoregulation resulting in excessive heat that manifests as thermal discomfort in neutral ambient temperatures and moderate to extreme cold tolerance, and produces REM sleep-related problems and parasomnias, such as night-terrors and hypnogogic hallucinations. Clinically, FOH is associated with the advent in childhood of frequent, recurrent, vivid nightmares with themes of pursuit and abandonment. The apparent psychological sequelae of exposure to this frightening imagery is fear sensitization and auto-traumatization. A developmental sequence of fear based defensive behaviors arises and includes obsessive bedtime rituals, fear of the dark, separation anxiety, contamination fears, hypervigilance, perfectionism, misperception of neutral stimuli as threatening, as well as reactive aggression in response to limit setting and perceived threat or loss. Ketamine, chosen as a potential treatment because of its effectiveness in reducing fear sensitization and dose-dependent lowering of body temperature in preclinical studies, has been associated with sustained improvement in otherwise refractory youths. We present a detailed description of this heritable disorder, link its clinical features to a potential disturbance in brain derived neurotropic factor (BDNF) and orexin, and indicate how ketamine rapidly affects BDNF through multiple mechanisms, to produce a dramatic beneficial response in youths with this disorder