The most important therapeutic advances in psychiatry, as in general medicine, have been the discovery of specific pharmacological or physical agents for the various disease conditions.  Similarly, the logical answer to the thalamic dysfunction states would be a drug possessing a specific reversing effect on the thalamic disturbance -- in other words, a powerful euphorigenic drug which would be therapeutically effective and at the same time free from the objectionable properties usually associated with narcotic compounds.

The ideal euphoriant for clinical use should possess the following properties:  It must induce a high degree of euphoria; must be stable and fully active by the oral route; be reasonably rapid-acting; and have a prolonged action.  It must be of low toxicity, non-cumulative, and free from after-effects and undesirable effects on the higher cortical functions, such as impairment of concentration, judgment, and memory.  Most important of all, it must not have the property of inducing the condition of addiction or physical dependence when administered for long periods.
  
The last mentioned point is of special importance, since there is a common and wide spread belief that all euphoriant drugs are necessarily habitforming, whereas this is in fact not the case.  The true addiction syndrome (physical craving, tolerance, abstention syndrome, and personality deterioration) is peculiar to the drugs of the ecgonine (or cocaine) and phenanthrene (or morphine) groups ; whereas mescaline and cannabis indica, the two most powerful euphoriants known, do not induce a comparable addiction.  The addiction forming property would therefore appear to depend on chemical constitution rather than degree of euphorigenicity, since the two compounds just mentioned are chemically unrelated to the cocaine and morphine drugs.  Theoretically, therefore, the addiction problem should not offer an insuperable obstacle to such a form of therapy, provided the compound employed is not one of the ecgonine or phenanthrene class.
  
Up to the present time no drug which fulfills these requirements has been known to medicine.  During the last century attempts were made to utilize the euphorigenic properties of cannabis in the treatment of depressive states, but these were found to be unsatisfactory for various reasons :  chief of these were the difficulty of obtaining reliable and stable preparations of this drug, its uncertain action, and its peculiar and undesirable side-effects, of which actual intensification of the dysphoria is one of the most common.  The discovery of the new synthetic cannabis-like derivatives of the dibenzopyran class within the last few years, however, has placed in our hands an entirely new type of euphoriant drug with properties which render it an extremely promising therapeutic agent in psychiatry.