Patients with carcinoid syndrome exhibit symptoms of aggressive impulse dysregulation.
OBJECTIVE
Carcinoid tumors can produce excessive amounts of biogenic amines, notably serotonin. We assessed psychiatric symptoms in carcinoid patients and peripheral metabolism of tryptophan, the precursor of serotonin.


METHODS
Twenty consecutive patients with carcinoid syndrome underwent a structured psychiatric interview applying DSM-IV (Diagnostical Statistical Manual) criteria. Tumor activity was measured by determination of 24-hour urine excretion of 5-hydroxyindoleacetic acid (5-HIAA) and platelet serotonin levels. Plasma tryptophan levels were measured and compared with sex- and age-matched references.


RESULTS
Fifteen patients (75%) fulfilled diagnostic DSM-IV criteria for a disorder of impulse control. Tryptophan plasma levels were lower in patients compared with controls (p =.031) and were correlated negatively with urinary 5-HIAA excretion (p =.001).


CONCLUSIONS
Impulse control disorders are prevalent in patients with carcinoid syndrome. The serotonin production by the tumor possibly decreases the tryptophan pool in the cerebrospinal fluid, which is the essential substrate for the production of brain serotonin as a pivotal neurotransmitter.
Russo
Sascha
S
Department of Biological Psychiatry, University Hospital Groningen, The Netherlands.
Boon
Jim C
JC
Kema
Ido P
IP
Willemse
Pax H B
PH
den Boer
Johan A
JA
Korf
Jakob
J
de Vries
Elisabeth G E
EG
D000368:Aged; D000374:Aggression / Q000523:psychology*; D001792:Blood Platelets / Q000737:chemistry / Q000378:metabolism; D002276:Carcinoid Tumor / Q000175:diagnosis / Q000378:metabolism / Q000523:psychology*; D039721:Diagnostic and Statistical Manual of Mental Disorders; D007174:Disruptive, Impulse Control, and Conduct Disorders / Q000175:diagnosis* / Q000378:metabolism / Q000523:psychology; D005260:Female; D006801:Humans; D006897:Hydroxyindoleacetic Acid / Q000652:urine; D008297:Male; D008875:Middle Aged; D010554:Personality Disorders / Q000175:diagnosis / Q000378:metabolism / Q000523:psychology; D011569:Psychiatric Status Rating Scales; D012701:Serotonin / Q000096:biosynthesis / Q000097:blood / Q000502:physiology; D014364:Tryptophan / Q000097:blood / Q000134:cerebrospinal fluid / Q000378:metabolism
D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D014364:Tryptophan