Automatic thoughts, a concept in cognitive behavioral therapy, are images or mental activity that occur as a response to a trigger (like an action or event). They are automatic and 'pop up' or 'flash' in your mind without conscious thought. Automatic thoughts can be beneficial. For example, you are driving and it starts raining very heavily. Automatically you think 'I need to be careful!' which leads to feelings of anxiety that cause you to drive more cautiously. Automatic thoughts can also have negative effects for people who have trouble with depression or anxiety.
For example, a person with anxiety sees an acquaintance frowning in their direction. They immediately think 'That person hates me!' which leads to feelings of anxiety, worry, and sadness. Thoughts like this can be damaging and unnecessary- the person who was frowning just had a pain in their leg! Cognitive behavioral therapy focuses on negative thought patterns and automatic thoughts that make people depressed or anxious. By changing these patterns and discerning how they occur can help treat emotional problems.