Inability or unwillingness to focus on an idea, issue, question, or theme of conversation. The patient "takes off on a tangent".
Stupor
Restricted and constricted consciousness akin in some respects to coma. Activity, both mental and physical, is limited. Some patients in stupor are unresponsive and seem to be unaware of the environment. Others sit motionless and frozen but are clearly cognizant of their surroundings. Often the result of an organic impairment. Common in catatonia, schizophrenia, and extreme depressive states.
Tangentiality
Inability or unwillingness to focus on an idea, issue, question, or theme of conversation. The patient "takes off on a tangent" and hops from one topic to another in accordance with his own coherent inner agenda, frequently changing subjects, and ignoring any attempts to restore "discipline" to the communication. Often co-occurs with speech derailment. As distinct from loosening of associations, tangential thinking and speech are coherent and logical but they seek to evade the issue, problem, question, or theme raised by the other interlocutor.
Thought Broadcasting, Though Insertion, Thought Withdrawal
See: Schneiderian First-rank Symptoms
Thought Disorder
A consistent disturbance that affects the process or content of thinking, the use of language, and, consequently, the ability to communicate effectively. An all-pervasive failure to observe semantic, logical, or even syntactical rules and forms. A fundamental feature of schizophrenia.
Vegetative Signs
A set of signs in depression which includes loss of appetite, sleep disorder, loss of sexual drive, loss of weight, and constipation. May also indicate an eating disorder.
