Substance use/abuse (including alcohol and/or other drugs) can be a major factor in the causes of anxiety. People who use alcohol or other drugs can do so for many different reasons, but it is usually because of some underlying issue, such as depression or social circumstances. When people use/abuse alcohol or other drugs, they may be placed into an altered mental and emotional state. The substances they are consuming may cause extreme ‘highs’ and ‘lows’ in the emotions of the person thus creating a sense of confusion as to what is ‘reality’. For example, if a person has taken a stimulant (including amphetamines, ecstasy, ice), their experience of being happy and full of energy is greatly enhanced. Then, as the effects of the drug wear off, their mood may decrease to a more depressed way of thinking. Both moods are intensified to the degree that there is no real ‘middle ground’ and the person does not feel any sense of stability. This would lead to a state of confusion and this confusion can be a major reason for anxiety.