The way that we think affects how we feel. As discussed in another post, our thinking patterns play a large role in depressed mood. People with depression are particularly susceptible to thinking errors (also known as ‘cognitive distortions’). These are thoughts and beliefs that are not grounded in reality, exaggerated, or simply just unhelpful. A cognitive-behavioural framework suggests that our thoughts, emotions, and behaviours are all interconnected. Sometimes, these negative thoughts can create a vicious cycle that maintains a depressed mood.

Imagine you recently started your MSc program in Biochemistry program, and you just finished your first exam. Unfortunately, you did not do as well as you hoped, having received a 70% on the exam. Thought, such as “I’m such a failure” and “I don’t deserve to be here” pop up and you begin to feel emotions of shame, guilt, and depressed mood. In response to these thoughts and feelings, you begin to withdraw more from your studies and social circle. The consequence is that you fall further behind, which only seeks to strengthen this vicious cycle.

This pattern is one explanation for how depression is maintained. As you hear these thoughts, you might notice that these thoughts are somewhat exaggerated compared to the actual situation. You might also relate to them a little in past situations. Below, I’ll go through 9 thinking errors that all people can experience that can impact our mood and are particularly common in depressed individuals.

Nine Common Thinking Errors

1. Probability Overestimation. Probability overestimation refers to when somebody severely overestimates the likelihood of something (usually something bad) happening. For example: “if I try, I will definitely (100%) fail”.

2. Catastrophizing. Catastrophizing is when a person takes a situation and immediately moves into the worse-case scenario or blows up potential negative implications to an extreme. An example would be “I did poorly on my biology 101 exam; I’m never going to get into medical school”.

3. All-or-nothing thinking. Also called black and white thinking, this is when somebody is very dichotomous in their way of thinking: they either did everything perfectly, or it went terribly. An example might be “if my baby is not always happy, then I have failed as a mother”.

4. Discounting the positives. Discounting the positives is a type of thinking error in which the person explains away positive events and focuses solely on the negatives. For example, “Sure I might have gotten positive feedback from several of my professors and did well on my most recent paper. That was just luck and I’m sure they say that to all their students.”

5. Personalizing. Personalizing is when a person assumes fault or responsibility for an event that may not be their fault. Specifically, they may think that because something happened, it means something about their character or who they are. “My husband is mad. It must mean that I am a bad partner”.

6. Fortune-telling. If you notice that you are often predicting something bad to happen if you were to do something, then you are probably engaging in fortune-telling. Examples include “If I ask my friend to spend time, they will say no” or “There’s no point in pursuing this hobby; I’m just going to quit anyways”.

7. Mind-reading. Mind reading is when we assume we know what another person is thinking. “She didn’t send me a text today – she must be angry at something I did”.

8. Emotional reasoning. People who tend to engage in emotional reasoning (also known as ‘following a feeling’) allow their emotions to become fact. For example, “I’m not happy all the time around my baby. It must mean I am a bad mother”.

9. Should statements. These statements include the word ‘should’ and usually leads to feelings of guilt and shame for not doing something they ‘should have’ done. “I should have known that my friend wanted me to call at that exact time”, “I should go to sleep at the same time every night. It’s my fault”.

Primary purpose is really to support a terrible pun
“I feel, therefore I am” – Descartes if his thinking style was emotional reasoning
I feel like I’ve made a similar pun before

A ‘Thought Provoking’ Quiz

Now that we have been familiarized with the different possible thinking errors, I figured this would be a good opportunity to have an interactive piece to this blog through a little quiz! Below, I will list out a few thoughts and your job is to determine which thinking error this might fall under. The answers will be on the section below.

“I forgot to call my mom yesterday. She probably thinks I am a terrible son”.

“I need to play a perfect game tomorrow; otherwise, I am a failure”

“If I don’t get at least 8 hours of sleep, I’m definitely going to feel terrible tomorrow”

“Our group got a really low mark on our presentation. It’s all because of me”

“I feel so tired. I don’t want to go hang out with my friends today”


1. Mind-reading. This person is assuming what their mother is thinking even though she has not explicitly or implicitly indicated her feelings towards them.

2. All-or-nothing thinking. The thought is very black and white: they are either perfect, or they are a failure.

3. Probability overestimation. The person believes that there is a very high chance (100%) that if they don’t get 8 hours of sleep, they will feel terrible. They may be ignoring times where they have had a reasonably good day even on crappy nights of sleep.

4. Personalizing. The person is personalizing the group’s failure to just themselves.

5. Emotional Reasoning. The person is using their feeling of fatigue to determine their behaviours (not going to hang out with friends). Although this is not necessarily a bad strategy all the time; if it is used often, then it may reduce positive reinforcement in our life. This is especially true in depression.


Thoughts can impact the way we feel and how we behave.

– Certain thinking errors can make somebody particularly vulnerable to depression (or other mental health challenges)

– We talked about nine common thinking errors that people can experience.

– Cognitive strategies (such as thought records and mindfulness) can be good evidence-based strategies to tackle thinking errors.

Best wishes,


-Photo by Kenny Eliason on Unsplash