From Hippocrates to the 18th century, phobic problems were described occasionally but not distinguished clearly as disorders in their own right. ‘‘Phobia’’ began to be used as a term early in the 19th century, after which it gradually gained acceptance in its current sense: an intense fear that is out of proportion to the apparent stimulus, cannot be explained or reasoned away, and leads to avoidance of the feared stimulus. In the later 19th century, many careful descriptions of phobic disorders appeared, starting with Westphal’s classic account of agoraphobia in 1871.
In 1895 Freud separated common phobias of things most people fear to some extent (death, illness, snakes etc.) from phobias of things or situations that inspire no fear in the average person, e.g. agoraphobia. That same year Henry Maudsley in his Pathology of Mind approved Westphal’s agoraphobia as a separate syndrome; in his 1895 edition, however, Maudsley included all phobias under melancholia and derided the big-sounding names given to each type of phobic situation, since many phobias were often found together or successively in the same case.
In 1913 Kraepelin included in his textbook a brief description of irresistible fears and irrepressible ideas, but did not separate phobic from obsessive–compulsive phenomena. Phobias achieved a separate diagnostic label in the International Classification of Diseases (ICD) in 1947, and in the American Psychiatric Association classification (now called DSM, for Diagnostic and Statistical Manual) in 1952. By 1959 just three out of nine classifications used in various countries listed phobic disorder as a diagnosis on its own. In the first two editions of the DSM all phobias were grouped together.
In the 1960s Marks and colleagues observed that the various phobias had different ages of onset and gender distribution and this provided the initial impetus for the split of phobias into agoraphobia, social and specific phobia; this was later adopted by the 3rd edition of the DSM and continued until the current DSM-IV and DSM-IV-TR. Anxiety and related disorders appeared in the ICD for the first time in its 7th revision and came under 18 rubrics in its 9th revision. This constituted the basis of the current classification of phobias in the ICD-10.