You've just read about a treatment that has been demonstrated in multiple controlled studies to have absolutely no effect on the disorder in question.Your neighbour swears,however,that the treatment worked for him.If your neighbour is being honest,what best explains his improvement

A)  His expectancies are masking the symptoms. 
B)  He never had a disorder in the first place. 
C)  His improvement happened to coincide with his use of the treatment. 
D)  He is delusional

It is possible that the neighbour's improvement happened to coincide with his use of the treatment, but the treatment itself did not cause the improvement. This is known as a coincidence or a spontaneous remission. It is important to note that anecdotal evidence, such as a single person's experience, should not be used as the sole basis for determining the effectiveness of a treatment. Controlled studies are necessary to establish whether a treatment is truly effective for a particular disorder.