Unhappy people may not have an active lifestyle, which unfortunately can increase their risk of having a mood disorder. "Research on sedentary adults has found that having higher levels of anxiety and depression was linked to greater likelihood of being sedentary, even three and six years later," clinical psychologist Traci Stein, PhD, MPH, tells Bustle. [The study, which was published in the journal Preventive Medicine, also found that greater physical activity is associated with better mental health, proving that exercise is important for mood.

When unhappy people are feeling down, it's hard to muster up the energy to socialize, but avoiding others and spending too much time alone can lead to more unhappiness down the line. "Social isolation leads to loneliness, which is highly correlated with unhappiness," says Mayer. Multiple studies demonstrate that people who are socially isolated are at a greater risk for depression as well as other mental health issues.

"Unhappy people often engage in argumentative or hostile conflicts with others," says Mayer. Research shows that people who have a hostile disposition tend to have higher rates of depression, according to the journal Annals of Behavioral Medicine. "Having a habit of being engaged in aggressive conflicts causes anger," says Mayer. And that anger may be an indication of unhappiness.

"Studies show that we tend to get what we expect," clinical psychologist Dr. Charlynn Ruan, Ph.D. tells Bustle. "Optimists tend to have more positive outcomes, and pessimists tend to have more negative outcomes." Although unhappy people may be more pessimistic, one study from the British Journal of Clinical Psychology found that pessimism itself — especially about the future — may be a leading cause of depression.

Focusing on negative memories tends to lead to feelings of unhappiness — and when you're unhappy, you tend to focus on the bad memories, creating a destructive feedback loop. "When we ruminate on negative memories, we open up our memory channels to all the bad things that ever happened to us, and we spiral downward," says Ruan. "But if we take time to consciously focus on gratitude or positive things, we stimulate positive emotions."

According to Stein, anxiety and depression are often associated with refraining from more nourishing foods. On the flip side, eating poorly can also affect your mental health, increasing your risk of anxiety or depression. Observational studies show that diets high in processed food and sugary products are associated with an increased risk of depression, according to the journal BMC Medicine.

People who value material objects are more likely to be depressed or unsatisfied with life. One study published in the journal Personality and Individual Differences found that materialistic people find it more difficult to be grateful for what they have, which causes them to be less happy.

Unhappy people tend to assume they have no control over their thoughts and feelings. "Studies show that we can change our brain's activity and its habits through a conscious effort," says Ruann. "But, most people don't realize they have this power and feel at the mercy of their mood and circumstances. But, there is a huge body of research that shows our thought patterns change our mental health and physical health."

Many people turn to a glass of red wine after a long day, but people who are unhappy may overdo it on the alcohol and other substances. Not only do depressed people tend to drink more than others, but drinking alcohol can also mess with your brain and increase your risk of depression.

Fortunately, the cycle of unhappiness can be broken once you recognize these patterns and make an effort to break yourself of them. But, if you are finding that difficult to do, it may be a good idea to seek help from a loved one or a therapist.