Abnormal thought possession is found in
Normally one experience's one's thinking as being one's own, although this sense of personal possession is never in the foreground of one's consciousness. One also has the feeling that one is in control of one's thinking. This loss of control is seen in obsessions. Ref- Fish psychopathology, 3e, pg 36.
Organic brain syndrome
Hysteria
Obsessive compulsive disorder
Neuroasthenia
Personality disorders