The negative symptoms of schizophrenia refer to a deficit or loss which the patient suffers within certain domains. These are the cognitive, emotional and behavioural domains.
Cognitively, the patients appears to struggle to generate thoughts. This is demonstrated by slowness of thoughts and response to questions or when its their natural turn to talk in a conversation. The thoughts might become what is termed vague or woolly. When there is this slowness of thought or inablilty to generate thoughts, it is termed poverty of thought or ideation. Thought block occurs when the patient stops talking mid-sentence, and then is unable to recall what he was talking about.
There might be the inability to talk, which is termed alogia.
Emotionally, there is a loss of facial emotional reaction. The facial expression is blank. This is termed a decreased range of affect. If there is absolutely no facial emotional responses it is termed flattened affect. Affect might also be incongruous which means that the facial expression does not reflect the mood of the person, eg excessively tearful but no reported mood symptoms.
These negative symptoms also include avolition which is the loss of initiation or motivation to perform. This is demonstrated by failure to start or adhere to tasks, or no goal-directed behaviour. This can range from their self care to any activities of daily living, and can extend to social activities, relationships and sex.
There might be complete withdrawal from any social interaction which is termed asociality.
Anhedonia is the inability to experience emotion. Patients describe feeling numb or emotionlly dead inside.
Anergia is lack of energy and asponteneity is a lack of spontenieity.
This is often misconstrued by family or friends as rude or being lazy and can put a strain on relationships.
The negative symptoms of schizophrenia can be very similar to a Major Depressive Episode, and can often get diagnosed as such, before the positive symptoms appear which makes the diagnosis of schizohrenia more obvious.