Anxiety and/or the depressive syndromes

The relationship of anxiety to depression in a number of the depressive and neurotic syndromes (agitated depressive syndrome, affective hypochondriacal syndrome, depressed obsessive-compulsive syndrome, phobic and obsessive-compulsive syndrome, anxiety state, depressive neurotic syndrome) is far from clear. Are anxiety and depression entirely separate disorders which may co-exist in the same patient? Does anxiety give rise to the depression? Does depression give rise to the anxiety? Are anxiety and depression manifestations of a single underlying disorders, dysphoria? Therapeutic responsivity to specific drugs suggest: relief of anxiety may reveal an underlying depression; anxiety syndromes which fail to respond to anxiolytics may respond to antidepressants; short-term relief of depression may occur at times with anxiolytics. Proposed mechanisms of action of depression and anxiety also involve overlap of the elements and systems involved. The basic sensations of pain, anticipation, depression and euphoria alone or in combination are sufficient to account for the dysphoric feelings and emotions when these sensations are associated with specific mental content. These may be related in turn to biogenic amines, beta-endorphins, diazepam receptors and possibly cocaine receptors.