The pineal gland has been implicated as a possible factor in mental disease. As long ago as the 19th Century, pineal extracts were used to treat mental disorders [Altschule, 1975]. Since the pineal function in humans regulates homeostasis of the body and body rhythms, a dysfunction of the pineal gland could be associated with mental disorders presenting with disturbances of normal sleep patterns, seasonal affective disorders, bipolar disorder, and chronic schizophrenia [Kovacs, 1971; Altschule, 1975; Carman, 1976; Jimerson et al., 1977; Nir, 1978; Ferrier et al., 1982; Beck-Friiss et al., 1985; Rosenthal et al., 1986; Wetterberg, 1987; Strassman, 1990; Roney-Dougal, 1991].

Other pathways have been proposed by which the malfunctioning of the melatonin generating system could contribute to mental disease. Melatonin can undergo cyclic dehydration to form 10-methoxy-harmalan, a powerful hallucinogenic substance [Nir, 1978]. Hallucinogenic indoleamines may be formed instead of melatonin because of faulty HIOMT activity [Hartley et al., 1973a, 1973b]. Roney-Dougal, while pointing to the pineal gland's involvement in altering our state of consciousness to a potentially psi state, discusses the presence of beta-carbolines, potent hallucinogens in the pineal gland [Ho et al., 1970; Quay, 1974; Langer et al., 1984; Roney-Douglas, 1991].

Strassman, in his discussion of the role of the pineal gland in consciousness [Strassman, 1990], proposes that the pineal gland, besides producing melatonin, is associated with unusual states of consciousness. It may synthesize and secrete hallucinogens in response to drugs or specific physical or mental states. These hallucinogens may be derivatives of the tryptamine or carboline family. 5-methoxy-tryptamine, which is a precursor of several of the compounds in question, has been found in pineal tissue [Bosin and Beck, 1979; Pevet, 1983] and in the cerebrospinal fluid [Koslow, 1976; Prozialeck et al., 1978].

The psychoactive beta-carbolines, which are also synthesized in the pineal, are formed from serotonin or tryptamine derivatives. As all beta-carbolines are strong MAOA inhibitors (the type that prevents the breakdown of serotonin), besides being psychoactive themselves they could contribute to the increase of activity of endogenous or exogenous tryptamine hallucinogens [Strassman, 1990].

In later parts of this paper, the author will discuss the relevance of the creation of hallucinogenic compounds in the pineal to the hypothesis that autism results from pineal gland imbalances.