Psychiatric symptoms of noradrenergic dysfunction: a pathophysiological view

Area of Science:

• Neuroscience
• Psychiatry
• Pharmacology

Background:

• The central noradrenaline system plays a crucial role in mediating stress responses and arousal.
• Abnormalities in arousal levels are a hallmark of functional psychoses.
• Noradrenergic dysfunction is hypothesized to underlie these arousal abnormalities.

Purpose of the Study:

• To review and infer psychiatric symptoms associated with central noradrenergic dysfunction.
• To examine the link between noradrenergic dysfunction and functional psychoses.
• To explore potential causes of noradrenergic dysfunction.

Main Methods:

• Pathophysiological inference from neuroscience literature.
• Examination of biological data in psychiatric disorders and psychotropics.
• Review of clinical and animal experimental data.

Main Results:

• Noradrenergic overactivity may cause hyperarousal symptoms (insomnia, anxiety, irritability, emotional instability, exaggerated fear/aggression).
• Noradrenergic underactivity may cause hypoarousal symptoms (hypersomnia, insensitivity to stress).
• Clinical data support the association between noradrenergic dysfunction and arousal symptoms in functional psychoses.

Conclusions:

• Central noradrenergic dysfunction is implicated in the arousal abnormalities seen in functional psychoses.
• The sedative effects of anxiolytics and antipsychotics may stem from their anti-noradrenergic actions.
• Excessive stress may be a long-term cause of noradrenergic dysfunction.