Comments: Scientists lowered dopamine in a healthy young man. He experienced an array of symptoms. Porn addicts often experience similar symptoms (or more mild versions) during withdrawal, or in between porn sessions. The symptoms may result from shifts in dopamine receptor levels as well as low dopamine.
Am J Psychiatry 162:1755, September 2005 doi: 10.1176/appi.ajp.162.9.1755 © 2005 American Psychiatric Association
LIEUWE de HAAN, M.D., PH.D., JAN BOOIJ, M.D., PH.D., JULES LAVALYE, M.D., PH.D., T. van AMELSVOORT, M.D., PH.D., and DON LINSZEN, M.D., PH.D. Amsterdam, the Netherlands
To the Editor: A paradigm that induces acute dopamine depletion with the drug alphamethylpara tyrosine (AMPT), a reversible inhibitor of tyrosine hydroxylase, has been used successfully to assess the occupancy of striatal dopamine D2 receptors by endogenous dopamine in vivo (1). Here we describe the dramatic subjective experiences induced by acute dopamine depletion in one healthy volunteer. They included a whole spectrum of psychiatric symptoms and highlighted the contribution of the dopaminergic system to diverse major psychiatric disorders.
In our study, dopamine depletion was achieved by oral administration of 4.5 g AMPT in 25 hours, as described earlier (1). Striatal D2 receptors were assessed at baseline and after acute dopamine depletion by using the bolus/constant infusion [123I]IBZM technique (1). Acquisition, reconstruction, and analysis of the single photon emission computed tomography data were performed as described previously (2).
Mr. A was a healthy, extraverted, very well functioning 21-year-old medical student without even minor psychological difficulties or psychiatric disorders in his family. His Global Assessment of Functioning Scale score was 97. Written informed consent was obtained from Mr. A. We will describe the spontaneous reported subjective experiences after he started the first dose of 750 mg AMPT at t=0 hours (1).
No 7 Stonnen huet den Herr A méi Distanz tëscht sech a sengem Ëmfeld gefillt. Stimuli hat manner Impakt; visuell an akzeptabel Stimulatioune ware manner schaarf. Hien huet e Verloscht vun der Motivatioun an der Middegkeet. No 18 Stonnen huet hie Schwieregkeeten z'erwächen an d'Müdegkeet ze erhéijen; Ëmweltstimulatioune schénge schweier Hien hat manner Fléissegkeet vum Ried. No 20 Stonnen huet hie sech duerchernee gefillt. Hien huet gespannt gefillt virum Rendez-vous an hat en Drang fir seng Auer op obsessiv Manéier ze kontrolléieren.
No 24 Stonnen, hat den Här A bannenzeg Onrouen, Fluch vun Iddien; seng Iddie schénge geféierlech ze sinn, an hien konnt hien sech net erënneren Hien huet e Verloscht vu Kontroll iwwer seng Iddien gefillt. No 28 Stonnen huet hie sech geschummt, Angscht gemaach, Angschtgefiller an depriméiert. Hien huet gefaart datt d'Situatioun géif weidergoen. Zu där Zäit goufen Blepharospasm, Mask Gesiicht an Tremor bemierkt. No 30 Stonnen war hie midd an huet 11 Stonnen geschlof. No 42 Stonnen huet hie schlecht Konzentratioun. An den nächsten Stonnen ass hien erëm normal.
The striatal-to-nonspecific binding ratio was 27% higher after Mr. A took AMPT compared to the baseline situation, indicating severe acute dopamine depletion (1).
During increasing dopamine depletion in this case, a range of subjective experiences appeared and disappeared consecutively. These experiences resembled negative symptoms, obsessive-compulsive symptoms, thought disorders, and anxiety and depressive symptoms and highlight the importance of the role of dopamine in major psychiatric disorders. In former studies, AMPT was found to lower mood, induce fatigue, decrease subjective alertness, and/or induce extrapyramidal symptoms in some healthy individuals (reviewed in reference 3).
Well déi subjektiv Erfarungen wéinst akuter Dopamin-Ofarmung dramatesch kënne sinn, gleewe mir, datt Sujete, déi un dopamin-Depletiounsstudien deelhuelen, gutt informéiert solle ginn iwwer temporär awer intensiv Nebenwirkungen.
Referenze
1. Verhoeff NP, Kapur S, Hussey D, Lee M, Christensen B, Papatheodorou G, Zipursky RB: A simple method to measure baseline occupancy of neostriatal dopamine D2 receptors by dopamine in vivo in healthy subjects. Neuropsychopharmacology 2001; 25:213–223[CrossRef][Medline]
2. Booij J, Korn P, Linszen DH, van Royen EA: Assessment of endogenous dopamine release by methylphenidate challenge using iodine-123 iodobenzamide single-photon emission tomography. Eur J Nucl Med 1997; 24:674–677[Medline]
3. Booij L, Van der Does AJ, Riedel WJ: Monoamine depletion in psychiatric and healthy populations. Mol Psychiatry 2003; 8:951–973[CrossRef][Medline]
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