When asked to think about someone who has depression, you may imagine a person in isolation and living a very rough lifestyle.

However, the stereotypical description of depression is a far cry from what the mental illness can truly look like. People experiencing depression can lead a normal life involving a stable romantic relationship, a steady group of friends, and perform well at their job.

Those with high-functioning depression won't outwardly appear there is something wrong, but on the inside, they can be feeling an overall emptiness and a significant decreased quality of life.

Here are eight signs you or a loved one may be experiencing high-functioning depression.

1. Change in sleeping patterns

Whether you're experiencing difficulty sleeping or sleeping too much, any change in your sleeping patterns is an indication you may have high-functioning depression.

As there is certain amount of hours the average person needs to sleep, too few or too many hours can cause your depression to get worse.

"Good sleep is key to good mental health," explains Carol Landau, a clinical professor of psychiatry at Brown University.

2. Difficulty experiencing joy

While people's interests constantly change and evolve, if you no longer feel joy doing things you used to love, it's a stark warning sign something has gone awry.

For instance, if you used to love playing the guitar, but no longer feel like strumming a few strings, there's a chance you may be experiencing high-functioning depression.

"The things that used to give you joy, such as playing with your dog or running, no longer bring you happiness," clinical social worker and therapist Kimberly Hershenson said. "These things may be avoided because they now feel more like a chore."

Another example of high-functioning depression would be a lack of enthusiasm over a promotion, the start of a new relationship, or family vacation. While you may temporary feel an improvement in your mood, it will soon be muted.

3. Critical of yourself and others

People who suffer from high-functioning depression are often overly critical of themselves and others.

These individuals are overachievers who don't feel whatever they accomplish is ever good enough. While it may seem like this is the response of a go-getter, it can seriously harm their self-esteem.

"Finding fault with yourself, beating yourself up constantly, or thinking others are always wrong are negative thought patterns that may be another sign of depression," Hershenson said.

6. Trouble focusing

If you find it difficult to focus on or become engaged in school, work, or even regular conversations on the rare occasion, there's nothing to be worried about.

However, if you're constantly zoning out or can't concentrate when performing a task, the inability to think clearly can be a sign of high-functioning depression.

5. Difficulty making decisions

Feeling self-doubt is one of the most noticeable signs someone is experiencing depression. While it's normal to occasionally have difficulty making up your mind on major life decisions, questioning your every choice isn't.

"Questioning whether you're in the right job, the right relationship, or having trouble making decisions may be signs of depression," Hershenson said. "If you find yourself questioning every move you make, this may be more than normal indecisiveness."

6. Increased feelings of agitation and anger

If you're annoyed at the little things you never seemed to notice before, this may be a sign of high-functioning depression.

For example, if you blow up at your spouse, friend or child over something that could be solved by a calm conversation, there is reason for concern.

"Very often mild depression can mask itself," clinical psychologist Dr. Josh Klapow said. "Often depression can present as irritability."

"You might be in a bad mood and feel cranky, irritable, and down "” but not sad. Irritability is a symptom of depression both mild and moderate," he added.

7. Diminished energy

Frequently feeling sluggish and unable to muster the mental, emotional, or physical energy to do your usual day-to-day tasks is another critical sign you're suffering from depression.

"If getting through the day feels unbearable "” even if you've had adequate sleep "” or you feel like you don't have the mental capacity to deal with life, these are symptoms of high-functioning depression," Hershenson explained.

8. Constant worrying

If you constantly fill your mind with worries, it may be a sign of high-functioning depression. While it's normal to experience uneasiness in high-stress situations, having anxious thoughts throughout the day is a cause for concern.

Frequently feeling distressed (for no reason) over your friendships, romantic relationships, the opinions of others, and the choices you made in the past and decisions you will make in the future is not the definition of a healthy mindset.

Mitigating the symptoms

Luckily, are several coping mechanisms for dealing with depression, with one of the largest ones being reaching out for help.

While it's important to lean on family and friends for support, it's also beneficial to talk to a trained professional about your feelings. They're not there to judge you, but to attentively listen and offer advice on how to relieve your depression and keep it at bay.

It's also valuable to keep up with your social activities, even if you don't want to. Being around others can have you feeling back to normal and keep you in your regular groove instead of retreating into isolation.

Be mindful at making sure you take care of your health by getting the necessary eight hours of sleep and eating well. A bad diet on no sleep definitely won't help.

There are also medications to help stabilize your mood, but you must see a doctor beforehand.

If you or a loved one are experiencing any form of depression, there is no shame in seeking help.

[H/T: Bustle, Help Guide, Reader's Digest, Scary Mommy]