What is depression?


Everyone feels low at times. Depression is different. When a person is depressed, they have a number of symptoms that linger for most of the day, for more than 2 weeks. These symptoms are distressing and disturb a person's life.


Symptoms of depression include:

  • Low mood (e.g. feeling sad, down, empty, hopeless) or a loss of pleasure/interest in things

  • Weight changes (either gain or loss), or appetite changes (either gain or loss)

  • Sleep disruption (oversleeping or undersleeping)

  • Feeling either restless or slowed down 

  • Suicidality (i.e. thinking about death, thinking about ways to commit suicide, attempting suicide)

  • Fatigue

  • Feelings of worthlessness or excessive (inappropriate) guilt

  • Difficulty concentrating 

If a person has five or more of these symptoms, most of the day, for more than 2 weeks, they may be given a diagnosis of 'Major Depressive Disorder'. People also refer to this as 'Clinical Depression', or just 'Depression'. The diagnosis is given when these symptoms cause a person distress or if they get in the way of their life. They also can't be due to another condition (e.g. thyroid malfunction).


What causes depression?


  • Genetics - Some people are more prone to low mood and depression than others. This may be partly due to their genetics. Depression can run in families.

  • Biology - Certain medical conditions (e.g. hypothyroidism), and drugs (e.g. alcohol, marijuana) can mimic depression. It's important to rule these factors out when diagnosing depression. 

  • Inactivity - Be inactive cuts us off from people and fun experiences. We're also unlikely to produce. This can make it hard for us to feel good about ourselves and life. As a result, our mood can deteriorate.

  • Negative thinking - A cause and consequence of depression is negative thinking. Depressed people can tend that negative events will never end (rather than the


How is depression treated?


Cognitive Behavioural Therapy (CBT) has been found to be effective in treating depression. CBT teaches people the skills to manage their moods. Treatment usually includes:


  • Lifestyle changes - Exercise and getting enough sleep is important. Avoiding alcohol, drugs, and stimulants (e.g. caffeine) can also help with anxiety.

  • Thought challenging - Negative thinking drives depression. Thought challenging helps with this. People are taught to ask "is this thought true?", "what would I advise my friend to do in this situation?", "why do I have to be perfect in all that I do?"

  • Behavioural activation - Forcing yourself to socialise, be productive and plan fun activities are several things one can do to feel better. It may not be immediate, but with time, our moods can return to normal.

  • Problem-solving - CBT places emphasis on finding solutions. Using a structured approach can be helpful.


This video explains how depression is treated using CBT:



About me

I am a Clinical Psychologist in North Sydney who treats depression using CBT. Please get in contact to learn more.


* Last updated: Jan 2020.

* The document is for information purposes only. Please refer to the disclaimer.