Anxiety transtorno induced by unknown or não especificado psychoactive substance is characterised by anxiety symptoms (e.g., apprehension or worry, fear, physiological symptoms of excessive autonomic arousal, avoidance behaviour) that develop during or soon after intoxicação com or abstinência from an unknown or não especificado psychoactive substance. The symptoms are not better explained by a primary mental transtorno (e.g., an Anxiety and fear-related transtorno, a Depressive transtorno com prominent anxiety symptoms), as might be the case if the anxiety symptoms preceded the onset of the uso of the unknown or não especificado psychoactive substance, if the symptoms persist for a substantial period of time after cessation of the uso of the unknown or não especificado psychoactive substance or abstinência from the unknown or não especificado psychoactive substance, or if there is other evidence of a pre-existing primary mental transtorno com anxiety symptoms (e.g., a history of prior episodes not associated com the uso of the unknown or não especificado psychoactive substance).