What is mental illness? Common mental health disorders explained

The term ‘mental illness’ refers to a group of conditions that affects mental health and wellbeing.  Mental illnesses affect how a person interacts with the world and with other people. This can include how someone thinks, feels, and behaves. A mental illness diagnosis is made by a professional using specific criteria.

There are many different types of mental illnesses, and different people may experience the same type of mental illness in different ways. Below are just some of the more common mental illnesses in Australia.

Mood disorders

Mood disorders are conditions that affect the way a person feels to the point where it negatively impacts on their life. This group of illnesses includes depression and bipolar disorders. Mood disorders can affect anyone, from any walk of life, and can come on at any age, although children and young people may not have the same symptoms as adults.

The most common types of mood disorders are:

• Major depression, where a person will feel a deep sadness for two weeks or more
• Bipolar disorder, where a person might experience periods of depression as well as periods of mania (a state where someone might feel very happy, excited, irritable, restless, energetic or hyperactive)

Addiction and substance abuse

Addiction is a serious condition where a person has lost control of their substance use to the point where it may be harmful to them.

Substance abuse is the intentional misuse or overuse of intoxicating substances. This can include using prescription medicine in a way other than how it is prescribed, often by taking a higher dosage or using it more regularly or using it when it is not prescribed to you.

Addictions can go beyond just substances however, and can include things like gambling, shopping, work or social media usage.

Eating disorders

An eating disorder is a potentially deadly health condition that relates to a person’s relationship with food and eating. The person may have a distorted view of their own appearance, leading to an obsession with dieting, restricting food intake or binging and purging (throwing up).

Common eating disorders include:

• Binge eating disorder, where a person will compulsively eat very large amounts of food
• Bulimia nervosa, where a person will binge eat and then use vomiting, laxatives or diet pills to ‘purge’ the food from their body
• Anorexia nervosa, where a person will restrict their food to the point of intentional starvation, while still believing themselves to be ‘fat’ or at risk of gaining weight

Obsessive-compulsive disorder (OCD)

OCD can present itself in a number of ways, but the core symptom of the disorder is intrusive, persistent negative thoughts.

A person with OCD may believe that performing rituals, such as counting, or ‘checking’ things many times, like ovens being turned off or doors being locked, will make the intrusive thoughts stop.

Personality disorders

A personality disorder is an ongoing way of thinking, behaving and feeling that is very extreme and causes major interruptions to a person’s life. There are many different ways personality disorders can present themselves, but they are generally grouped into three clusters:

• Cluster A, where a person has difficulty relating to others and behaves in a way others would describe as ‘strange’ or ‘unusual’. This cluster includes paranoid personality disorder, schizoid personality disorder and schizotypal personality disorder.
• Cluster B, where a person has difficulty with their self image or relationship to the world and other people. This cluster includes antisocial personality disorder, borderline personality disorder and narcissistic personality disorder.
• Cluster C, where a person has extreme difficulty socialising and might be described as extremely shy or withdrawn. This cluster includes avoidant personality disorder, dependent personality disorder and obsessive compulsive personality disorder.

Reach out for support

Just like physical illnesses, the treatment and specialist care a person might need for one mental illness may not be suited to the next person.

As the largest private provider of mental health care in Australia, we are dedicated to making a real difference in the lives of those we treat, with whatever pathway they need. We offer a range of services designed to support people experiencing mental health issues like anxiety, depression, and a wide range of other conditions.

We encourage you to reach out to our expert team who can assist you in finding the right avenue for your mental health care journey.