The "pink spot" and schizophrenia.

Abstract

THE idea that the “pink spot” is uniquely associated with schizophrenia1–3 is now in doubt because of its reported presence in normal individuals4,5 and in patients suffering from Parkinson's disease6. Additionally, some doubt must be cast on its identification as β-3,4-dimethoxyphenylethylamine (DMPE)1,7. The evidence supporting the finding that the “pink spot” is DMPE rests on its almost exact correspondence with DMPE in certain paper chromatographic1,4,7 and gas chromatographic8,9 systems, the chromatographic similarity of prepared derivatives1,7 and the similarity of the melting point range of the hydrochlorides22. This indirect identification of the “pink spot” as DMPE is of great interest because of the hypothesis10,11 that in schizophrenia abnormal methylation of catecholamines might occur. This hypothesis is strengthened by the chemical similarity between DMPE and the halucinogenic substance mescaline and also by the observation that the feeding of substances capable of donating a methyl group can cause an exacerbation of schizophrenic symptoms12–14.