What is Mental Illness? 

Mental illness is a condition which negatively affects an individual’s thinking, emotions, and/or behavior so that daily functioning is impaired and/or the quality of relationships is reduced. A professional diagnosis of mental illness, however, is only made when the symptoms persist or increase over a specified period of time. A bad day, or two, or even a week is not an indicator of mental illness.

Who has it?

Anyone can suffer the effects of mental illness. It is not a sign of weakness, laziness, or a character deficiency. Just as with bodily illnesses, mental illnesses occur when stressors overcome an individual’s ability to resist. Mental illness is often difficult to cope with, it is even more difficult to manage because of the misunderstandings and stigmas associated with it. Remember: if you are human, mental illness can happen to you. 

Why do people have a Mental Illness? 

The cause of mental illness is simple to understand and diagnose in some individuals, yet extraordinarily complex in others. A mental health condition can have more than one contributing factor. Genetics predisposes some to mental illness. Trauma, living conditions, life choices, and addictions can contribute toward developing a  mental illness. For some, there are multiple related causes. Whatever causes mental illness in one person will not necessarily cause in another.  

When do people become mentally ill? 

The onset of mental illness can occur at any time during a person’s life. Symptoms of mental illness can show up in childhood, adolescence, adulthood, and the senior years. However, the years between 18 and the late 20’s account for the greatest percentage of initial mental health diagnoses.  

My first symptoms of a mental illness developed was when I was 18 but it wasn’t until 5 months later, when I had just turned 19, that the symptoms became severe enough to seek help and I was diagnosed with major depression. Exactly a year later, I was diagnosed with OCD. Another year later, I was diagnosed with psychosis, but this is a symptom of mental illness, rather than a mental health disorder itself. Later that year, I got a second opinion and got diagnosed with bipolar. 

The first signs and symptoms of a mental illness can occur at any stage of life. Some may appear during childhood and others may not manifest until old age. One indicator of potential mental illness is family history. If a person has a family history of mental illness, they are at a higher risk of developing this type of illness.

Types of Mental Illness

Depression Disorders

Symptoms of depression can include changes in sleep or appetite, lack of concentration, loss of energy, loss of interest and pleasure in normal activities, low self-esteem, and hopelessness. Changes in sleep may include trouble falling asleep, staying asleep, or sleeping longer periods of time. People may experience changes in appetite that lead to weight gain or loss. Eating more or less than usual becomes an often unrecognized way to cope with the effects of depression. Those with major clinical depression often have great difficulty concentrating on everyday activities such as working, driving, reading, and watching television. They may also feel continually fatigued regardless of the amount time they have slept, have low energy resulting in thinking, moving, and talking more slowly than usual, or be unable to perform normal daily routines. People may lose interest in their normal activities and/or lose the ability to experience pleasure. This may include having no desire to eat, work, socialize, engage in leisure activities, or have sex. Chronic low self-esteem often develops when depressed people focus internally on their losses or failures and blame themselves for their inability to sustain normal activities, and relationships. This can lead to a downward spiral characterized by excessive guilt and feelings of helplessness. This spiral can further lead to feelings of inescapable hopelessness. A severely depressed person can feel totally convinced that nothing good will happen again --ever-- in his/her life. The physical, mental, and emotional pain can become so all-encompassing that thoughts of suicide as a solution to ending the quiet agony of depression begin to intrude, and sometimes, tragically, are carried out.

Major Depression

A diagnosis of depression may occur after a person experiences 5 or more symptoms for at least two weeks.

Seasonal Affective Disorder 

There are two kinds of seasonal affective disorder, one for fall and winter, sometimes known as winter depression, and a summer-onset depression. Symptoms of winter depression include irritability, tiredness or low energy, problems getting along with other people, hypersensitivity to rejection, heavy feeling in the arms or legs, oversleeping, appetite changes, and weight gain. Symptoms of summer depression include depression, insomnia, weight loss, poor appetite, and agitation or anxiety.

Postpartum Depression

Postpartum Depression can occur in women after childbirth and is more intense and longer lasting than the “baby blues”. Symptoms of the “baby blues”, which can be experienced very differently (or not at all) by mothers following their baby’s birth, include mood swings, anxiety, sadness, irritability, crying, decreased concentration, and trouble sleeping. These symptoms occur for a few days to a week or two and are the result of the major hormonal changes occurring after delivery. 

However, postpartum depression symptoms occur longer and are more intense. Symptoms may include a loss of appetite, insomnia, intense irritability and anger, intense fatigue, loss of interest in sex, lack of joy in life, feelings of shame, guilt, or inadequacy, severe mood swings, difficulty bonding with your baby, withdrawal from family and friends, and thoughts of harming yourself and your baby.

Anxiety Disorders

All anxiety disorders have a common symptom of persistent, excessive fear or worry. There are both emotional symptoms and physical symptoms. The emotional symptoms may include feelings of apprehension or dread, feeling tense and jumpy, restlessness or irritability, anticipating the worst, and being watchful for signs of danger. Physical symptoms include having a pounding or racing heart and shortness of breath, an upset stomach, sweating, tremors, and twitches, headaches, fatigue, and insomnia, frequent urination or diarrhea. 

Generalized Anxiety Disorder

Generalized Anxiety Disorder creates chronic, drawn-out worry about everyday life which can consume hours of a person’s day making it hard to concentrate or complete regular daily tasks. A person may be too fatigued by worry and, as a result, experience physical symptoms of headaches, muscular tension, and/or stomach upset/ nausea. 

Social Anxiety

Social Anxiety isn’t shyness, rather it creates intense fear in a person which is often driven by irrational worries about being humiliated in public, such as “I’ll say something stupid”. A person with social anxiety may not participate in conversations, class discussion, offer their ideas and opinions, and may become isolated. Unchecked, social anxiety can result in panic attacks.

Panic Disorder

Panic attacks are sudden feelings of terror which can strike without warning. A person can be completely disabled by a panic attack and seek medical treatment in the mistaken belief that the physical symptoms are those of a heart attack. The symptoms (chest pain, heart palpitation, dizziness, shortness of breath, and stomach upset) are similar to those of a heart attack and can range from mild to severe. 


What makes phobias unique is that associations with certain places, events, or objects create powerful reactions of a strong and irrational fear. These phobias come with several triggers which can take over a person’s life.

Obsessive-Compulsive Disorder

Obsessive-Compulsive Disorder (OCD) symptoms usually last more than a hour a day and can interfere with daily life. Obsessions are intrusive irrational thoughts that occur over and over again. People with OCD know these thoughts are irrational but are afraid they might be true. Examples of obsessions include thoughts of harming or having harmed someone, doubts about having done something right, such as turning off the stove or locking a door, unpleasant sexual images, and fears of saying or shouting inappropriate things in public. 

Compulsions are repetitive acts that temporarily relieve stress brought on by an obsession. People with OCD act on these compulsions to prevent bad things from happening and relieve anxiety. Examples include hand washing due to a fear of germs, counting and recounting money because a person can not be sure they added it correctly, checking to see if a door is locked or the stove is off, and mental checking that goes with intrusive thoughts.


There are two states a person with bipolar disorder goes through, mania (or hypomania) and depression. Hypomania is a milder form of mania. During periods of mania people have an elevated mood in which they frequently behave impulsively, make reckless decisions and take unusual risks. Moods can rapidly become more irritable, behavior be more unpredictable, and their judgment can be impaired. Most of the time, they are unaware of the negative consequences of their actions. During the depression phase of bipolar disorder, there are both physical and emotional symptoms that inhibit a person’s ability to function almost every day for a period of at least two weeks. 

Bipolar I

Bipolar I is when people experience one or more episodes of mania and/or depression but a depressive episode isn’t necessary for a diagnosis. A person’s manic or mixed episodes must last at least seven days or be so severe that they require hospitalization. 

Bipolar II 

Bipolar II is a subset of bipolar when people experience depressive episodes going back and forth with hypomanic episodes, but never a full manic episode. 

Cyclothymic Disorder

Cyclothymia is a chronically unstable mood state when people experience hypomania and mild depression for at least two years. They can have brief periods of a normal mood, but these periods last less than two months.

Bipolar “other specified and “unspecified” 

This is diagnosed when a person doesn’t meet the criteria for either bipolar I, II, or cyclothymia but has had periods of significant abnormal mood elevation. These symptoms may either not last long enough or not meet the full criteria for episodes necessary to diagnose bipolar I or II. 

Dissociative Disorders

Symptoms of dissociative disorders may include significant memory loss of specific times, people, and events; out-of body experiences, as though you are watching a movie of yourself; depression, anxiety, and thoughts of suicide, a sense of detachment from your emotions, or emotional numbness; and a lacking a sense of self-identity. 

Dissociative Amnesia

The most common symptom is having difficulty remembering important information about themselves. This may be surrounding a particular event or information about identity and life history. 

Depersonalization disorder

Symptoms of depersonalization disorder can include constant feelings of detachment from actions, feelings, thoughts, and sensations and/or feel like people and things in the world around them are unreal. 

Dissociative Identity Disorder

People with DID alternate between multiple identities. A person may feel like one or more voices are trying to control their minds, have unique names and characteristics, experience gaps in memory of daily events, personal information, and trauma. Men are more likely to deny symptoms and trauma histories and portray more violent behavior. 


Schizoaffective Disorder

Depending on the mood disorder diagnosed, either depression or bipolar, people will experience different symptoms (or combinations of symptoms) which include hallucinations, delusions, disorganized thinking, depressed mood, and manic behavior. Hallucinations are seeing or hearing things that aren’t there and delusions are false, fixed beliefs that are held regardless of evidence. A person may switch very quickly from one topic to another or provide answers that are completely unrelated. Depressed mood includes experiences of sadness, emptiness, feelings of worthlessness, or other symptoms of depression. Manic behavior would include feelings of euphoria, racing thoughts, increased risky behavior, and other symptoms of mania. 


Symptoms of schizophrenia falls under four categories, hallucinations, delusions, negative symptoms and cognitive issues or disorganized thinking. Hallucinations include a person hearing voices, seeing things, or smelling things that others can not perceive. Delusions are false beliefs that don’t change even when the person who holds them is presented with new ideas or facts. Negative symptoms include being emotionally flat or speaking in a disconnected way, unable to start or follow through with activities, show little interest in life, or sustain relationships. Disorganized thinking may include a struggle to remember things, organize their lives, or complete tasks.

Post-Traumatic Stress Disorder

Symptoms of PTSD include intrusive memories, avoidance, dissociation, and hypervigilance. Intrusive memories can include having flashbacks and reliving the moment of trauma, bad dreams, and scary thoughts. Avoidance can include staying away from certain places or objects that are reminders of the traumatic event, or difficulty remembering the event. Dissociation can include out-of-body experiences or feeling that the world is not real. Hypervigilance includes being startled very easily, feeling tense, trouble sleeping, or outbursts of anger.

Eating Disorders

Anorexia Nervosa

People with anorexia will deny themselves food to the point of starvation while obsessing about weight loss, engage in binge eating and purging behaviors, and/or exercise obsessively. There are mental/emotional symptoms as well, such as irritability, social withdrawal, lack of mood or emotion, not able to understand the seriousness of their situation, and/or fears of eating in public. 

Bulimia Nervosa

A person with bulimia feels out of control while bingeing on excessive amounts of food within a short time, then attempt to regain control by forced vomiting, laxative overuse, and/or excessive exercise. The emotional symptoms include low self-esteem about one’s physical appearance, feelings of being out of control, feeling guilty or ashamed about eating, and/or withdrawal from family and friends. 

Binge Eating Disorder

A person with Binge Eating Disorder loses control over their eating and eats very large amounts of food in a short period of time. This results in feelings of embarrassment, disgust, depression, and/or guilt about this behavior.  


​Dementia is a mental disorder that develops among the elderly. It is a chronic progressive disease that affects memory, intelligence, and language, and general competency. It usually extends from onset of symptoms over a period of eight to ten years and results in death. The most common type of dementia is Alzheimer’s. Often, family member initially are the caregiver to those with dementia, but once they can no longer provide proper care, dementia patients are likely to be put in nursing homes.

About Mental Illness

From Darkness Into Light Resources

Mental Health  

Providing hope, encouragement, inspiration, and resources for those dealing with mental illnesses as well as their family and friends.