廣泛性焦慮疾患的心理病理：病態憂慮、注意偏誤、與憂慮的後設認知

Abstract

廣泛性焦慮疾患 (generalized anxiety disorder; GAD) 的核心症狀 – 病態憂慮 (pathological worry) 會嚴重干擾個人的認知功能，帶來負向情緒，同時也伴隨廣泛且持續的身體抱怨。本研究的目的在於探討注意偏誤與後設認知對病態憂慮的影響，透過兩個子研究，瞭解過去研究尚未充分了解的問題。在研究一中，36位未具診斷之參與者被隨機分配至注意威脅性刺激或注意中性刺激兩種注意偏誤操弄。兩組參與者在接受注意偏誤操弄後，都接受以數學記憶與運算為內容的心理壓力作業。研究一結果顯示，被操弄注意威脅性刺激的參與者相對於另一種注意偏誤操弄 (即注意中性刺激組) ，在壓力作業下表現出較高的主觀焦慮感、較高的心跳速率、以及較低的副交感神經活性。在研究二中，42位符合GAD診斷之類GAD組參與者與47位無診斷之控制組參與者，皆被隨機分配至注意威脅性刺激、注意中性刺激、或注意正向刺激等三種注意偏誤操弄。在注意偏誤操弄前後，參與者各接受一次隨機點偵測作業 (dot-probe task) 的測量，藉此瞭解兩組參與者的注意偏誤特徵以及注意偏誤操弄後的變化。之後參與者再接受憂慮引發作業誘發其憂慮狀態，並在此誘發作業後再接受第三次的隨機點偵測作業。參與者的兩種注意偏誤指標 (投注注意與抽離注意) 以及各實驗階段的心血管指標皆被紀錄，並以相關分析瞭解對憂慮的正負向後設認知與注意偏誤和憂慮嚴重度的關連性。研究二有幾項主要的發現：(1) 類GAD組參與者呈現對威脅性刺激與正向刺激的抽離注意困難 (difficulty disengagement) ； (2) 接受注意中性刺激操弄的類GAD組參與者，其抽離注意困難在操弄後降低； (3) 接受注意威脅性刺激操弄的控制組參與者在憂慮引發作業下，相對於其他兩種操弄，呈現較高的心跳速率與較低的副交感神經活性； (4) 參與者對憂慮的負向後設認知與對威脅性刺激的抽離注意困難和憂慮嚴重度有顯著相關。綜合來說，本研究的結論與貢獻是：(1) 確認病態憂慮的定位與臨床研究重要性； (2) 與GAD和病態憂慮有關的注意偏誤是抽離注意困難； (3) 在壓力作業下，對威脅性刺激的注意偏誤會影響生理與主觀情緒層面的焦慮反應； (4) 對威脅性刺激的注意偏誤也會影響憂慮嚴重度； (5) 對憂慮的負向後設認知、憂慮嚴重度、及對威脅性刺激的抽離注意困難彼此有關。本研究於討論中，探討透過治療抽離注意困難及負向後設認知，進而改善病態憂慮的可能策略，以及臨床上可能的施行效果與可行性。

Pathological worry was the cardinal diagnostic feature of generalized anxiety disorder (GAD). In this study, we focused on the roles of attentional bias and meta-cognition in maintaining pathological worrying. In study 1, normal participants (n = 36) were randomly assigned to one of two attentional training conditions, with aims to induce attention toward threatening stimuli/neutral stimuli, respectively. All participants received a mental stress task after their respective attentional training phase. The results showed that greater anxiety, higher heart rate, and lower parasympathetic reactivity were observed for participants trained to attend toward threatening stimuli. In study 2, we further clarified two different patterns of attention mechanisms in subclinical GAD participants. Besides, the relations among the two patterns of attentional bias, the intensity of worry, and the meta-cognitions toward worry were also investigated. Subclinical GAD participants (n = 42) and normal participants (n = 47) were screened by Diagnostic Interview Schedule (DIS). After receiving baseline random dot-probe task, participants in each group were randomly assigned to three different attentional training conditions (attended to threatening stimuli, to neutral stimuli, or to positive stimuli) before worry-induction task. There were some main findings: (1) Subclinical GAD participants showed difficulty disengagement away from threatening stimuli and from positive stimuli compared to normal participants. (2) The extent of the difficulty disengagement was decreased in subclinical GAD participants who were trained to attend toward neutral stimuli. (3) Subclinical GAD participants showed lower parasympathetic reactivity compared to normal participants. (4) Normal participants trained to attend toward threatening stimuli showed lower parasympathetic reactivity during worry induction. (5) Negative meta-cognition (worry was uncontrollable or harmful) was correlated with the intensity of pathological worry and with the extent of difficulty disengagement away from threatening stimuli. The latent mechanisms among attentional bias and meta-cognitions regarding the maintenance of intensity of worry, and the implications of the results for treating pathological worriers or GAD patients are discussed.