This volume contains the proceedings of the fourth international symposium held in November 1970 at the Texas Research Institute of Mental Sciences in Houston. Leading psychiatrists, biochemists, and pharmacologists from the United States and Great Britain presented new material and reviewed current concepts concerning schizophrenia and the affective disorders, with particular reference to the neurochemical basis of the etiology and chemotherapy of these diseases. Although the multiple mechanisms of mental disease are still not fully understood, substantial progress has definitely been made. The greatest contribution has come through the development of new therapeutic agents that not only provide invaluable help to the mentally ill but serve as chemical tools for studying the biological mechanisms associated with the disease state. Studies concerning the proposed catecholamine and indolealkylamine hypotheses for affective disorders and the possible formation of endogenous. toxins in schizophrenia have stimulated significant new research. This book presents new studies of schizophrenia and the affective disorders in one volume. It is our hope that it represents an effective integration of basic biochemical and pharmacological research with current clinical findings and that it will increase understanding of the etiology of mental disease and provide an impetus for the development of more effective therapeutic agents. We thank Drs. Gordon Farrell, Samuel Gershon, A. Horita, Irwin Kopin, and Joseph Schildkraut for their help with the organization of the meeting and for chairing the corresponding sessions.

Enzymes: Implications in Mental Disease.- Multiple Forms of Monoamine Oxidase in Developing Tissues: The Implications for Mental Disorder.- Regulation of Catecholamine Biosynthesis: Tyrosine Hydroxylase and Dihydropteridine Reductase.- Behavioral, Metabolic, and Enzymatic Studies of a Brain Indoleethylamine N-Methylating System.- Transmethylation Processes in Schizophrenia.- Psychoactive Agents: Biological Actions.- Effects of Drugs on Catecholamine Synthesis.- Pharmacological Implications of the Effects of Amphetamine and Its Analogs on the Turnover Rate of Tissue Catecholamines.- Studies on the Mechanism of Action of 6-Methoxytetrahydro-Beta-Carboline in Elevating Brain Serotonin.- Comparison of the Effects of Electrical Stimulation and Iontophoretic Dopamine on Neurons of the Nigro-Neostriatal Pathway.- Biological Aspects of Affective Disorders.- Biogenic Amines and Affective Disorders.- Catecholamines and Affective Illness: Studies with L-DOPA and Alpha-Methyl-Para-Tyrosine.- Relationships between Stress and Brain 5-Hydroxy-tryptamine and their Possible Significance in Affective Disorders.- Interactions between Adrenocortical Steroid Hormones, Electrolytes, and the Catecholamines.- Thyroid-Imipramine Interaction: Clinical Results and Basic Mechanism.- Effects of Tricyclic Antidepressants on Norepinephrine Metabolism: Basic and Clinical Studies.- Brain Amines and Affective Disorders.- Overall Review.- Panel Discussion.- Genetic and Metabolic Factors in Mental Disorders.- Heterogeneous Distributions of Schizophrenia.- Frequency of Genetic Polymorphism: Implications for Mental Disease.- Purine Metabolism and Abnormal Behavior in Children.- Modern Concepts of Chemotherapy.- Chemotherapy of Schizophrenia.- Chemotherapy of Manic-Depressive Disorder.- Chemotherapy of Depression.