The results of these preliminary trials would suggest that we have in this class of compounds a promising therapeutic agent for the treatment of the chronic and intractable depressive states.  Synhexyl, the most active of this class, has the advantages of low toxicity, minimum of side-effects, ease of administration, and chemical stability.  Its use is not contraindicated by the presence of coexisting organic disease, and it is suitable for out-patient practice.  Its use does not interfere with other therapeutic measures, such as occupational therapy and psychotherapy.  It is free from the risks and disadvantages of the more drastic forms of treatment, and might replace those methods for the milder depressions of later life where, for any reason, the more drastic procedures are contraindicated.
Its main drawbacks at present are its insoluble nature, slow and uncertain action, and comparatively weak analgesic effect, so that it is relatively ineffective in the severer forms of sensory thalamic dysfunction syndrome.  Experiments are at present in progress with the object of producing a water-soluble form with a higher degree of analgesic activity.
The syndrome of thalamic dysfunction and the principles of its treatment with euphorigenic drugs are described.

The properties and pharmacology of synhexyl, a new drug of the synthetic tetrahydracannabinol class, are examined.
The results of therapeutic trials with the drug in a series of 50 depressive patients are given.

My acknowledgments are due to the following :  The Research Department of Roche Products Ltd. and Dr. W. S. Maclay, of the Board of Control, for kindly providing supplies of synhexyl ; Dr. W. A. Bain, of Leeds University, for kindly making up the material for administration ; Prof. A. R. Todd, of Cambridge University, for kindly supplying purified cannabis extracts for clinical trial ; and Mrs. E. Bathurst, psychologist, Warlingham Park Hospital, for kindly undertaking psychometric tests on the patients tested with the drug.