60 陳先生目前42歲，於26歲時被診斷為精神分裂症，至今共住過精神科病房6次，多次復發乃因為未定時服用精神科藥物，近年來在家人的協助下，定期於精神科門診接受治療追蹤，已無幻聽和被害妄想等症狀。最近數個月來，家屬發現陳先生似乎比較少話，衛生習慣變得很不好，不愛洗澡，變得被動退縮，家屬常指責陳先生，陳先生雖無出現自傷或傷人行為的跡象，但某日在爭執中出現情緒非常激動無法立即平復之現象。陳先生最近幾個月的行為表現，以下列那種情況來解釋最適當？

 精神分裂症的正性症狀 精神分裂症的負性症狀

精神分裂症的認知障礙 精神分裂症合併憂鬱症狀

精神分裂症的負性症狀

Positive and negative symptoms

Schizophrenia is often described in terms of positive and negative (or deficit) symptoms.^[16]

The term positive symptoms refers to symptoms that most individuals do not normally experience but are present in schizophrenia. They include delusions, auditory hallucinations, and thought disorder, and are typically regarded as manifestations of psychosis.

Negative symptoms are things that are not present in schizophrenic persons but are normally found in healthy persons, that is, symptoms that reflect the loss or absence of normal traits or abilities. Common negative symptoms include flat or blunted affect and emotion, poverty of speech (alogia), inability to experience pleasure (anhedonia), lack of desire to form relationships (asociality), and lack of motivation (avolition). Research suggests that negative symptoms contribute more to poor quality of life, functional disability, and the burden on others than do positive symptoms.^[1