Clinical Depression: Signs, Causes & Treatment

By Ross Nelson, PsyD
Medically reviewed
September 10, 2020

Despite the fact that about 7% of US adults experience depression, the disease is still a mystery for many people in the world. It is complicated for many reasons, most notably because in some households and cultures it’s still taboo to speak directly about mental health issues.

While trends in recent years have shown that stigma surrounding mental illness continues to decrease, many people continue to ignore or dismiss the signs and symptoms of depression because it makes them feel like they are “weak,” “damaged goods,” or “less-than” for having a mental illness.

What Is Depression?

Clinical depression is a mental disorder that detrimentally affects the thoughts, emotions, and behaviors of the sufferer. This is a severe form of depression with symptoms lasting at least two weeks, but symptoms can frequently last for longer periods of time. It commonly includes low mood for the majority of one’s day.

Many people who struggle with depression have repeat episodes of depression throughout their lifetime. However, some individuals only experience a depressive episode once or twice in their lives.

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What Are the Different Kinds of Depression?

Not all depression looks the same and in fact, there are several different forms of depression, including persistent depressive disorder (a long-standing, low-grade form of depression), seasonal affective disorder (depression that relates to changes in the seasons), and postpartum depression (a depressive episode that initiates following the birth of a baby).

For the sake of clarification, the kind of depression we will address in these articles is major depressive disorder (MDD) or clinical depression. This type of depression is not caused by bereavement or by medical conditions that mimic depression (such as vitamin deficiency or thyroid issues).

It is also not to be compared with sadness or “the blues,” which are considered a reasonable short-term emotional response provoked by a somber or stressful event.

Major depressive disorder can occur at any age (including childhood) and across all races and genders. Women between 18-25 and those with mixed heritage have the highest prevalence of clinical depression.

The increase in prevalence in women may be due to hormonal changes such as menstruation, pregnancy, and menopause, but also due to non-biological reasons, such as life circumstance and cultural influences (e.g. unequal power and pay, limited access to resources, increased responsibilities, and history of physical, verbal, or sexual abuse).

Signs of Depression

It’s important to know up front that not everyone who has clinical depression shows obvious signs of being clinically depressed.

However, according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-V), the standard mental health handbook developed by expert professionals in the field, there are common signs and symptoms of clinical depression you can watch for, including but not limited to:

  • Persistent feelings of sadness, guilt or hopelessness
  • Apathy toward previously enjoyable activities
  • Lethargy
  • Having difficulty making decisions
  • Difficulty falling asleep, staying asleep, or excessive sleeping
  • Thoughts of suicide or thinking life is not worth living
  • Noticeable weight gain/loss or appetite change
  • Feeling restless or slowed down
  • Physical problems, such as pain or headaches, which are not attributable to other causes

It is noteworthy that these symptoms are not cookie-cutter. Some individuals who are suffering from clinical depression may be able to function normally to a limited degree, while others may not be able to get out of bed. Because men are less likely to seek help for their depression or share their experiences, symptoms may be muted, suppressed, or not reported to anyone at all.

Additional indicators may include increased anger or agitation, alcohol or substance abuse, and suicidal/homicidal thoughts or actions.

What Causes Depression?

The causes of clinical depression are not straightforward because there are many different variables, competing theories, and still inadequate evidence about the “causes” of depression and most psychiatric conditions.

Cognitive behavioral therapy, or the style of therapy that is proven to be most effective for treating depression and other psychological conditions, rests on the idea that negative thoughts (such as “I am worthless and defective”) are the cause of negative feelings (including depressed, “down,” and unhappy).

It is a common misconception, according to cognitive behaviorists, to think that it’s the situations and circumstances of life that cause negative emotions when it is actually the negative (and oftentimes unhelpful, unrealistic, or distorted) thoughts about situations and circumstances that cause negative emotional states.

What causes negative and depressed thinking commonly boils down to what makes us human: our biology/genetics (nature) and environment (nurture). Inherited traits from family members as well as the type of environment you grow up in can also result in more susceptibility to negative (and positive) mood states.

Hence, if your parents were/are depressed and/or you were raised in an environment that did not promote positivity, you have a higher chance of developing depression.

In the case of biological differences, there is evidence that the brain function of people who suffer from depression is different from those who do not. The limbic system is of particular interest to those studying depression because it’s the system that governs emotional activity, motivation, and stress.

Specifically, the hypothalamus, which regulates behavior, thinking, and hormonal functions, seems to play a large role among those with and without depression. An additional brain chemistry theory holds that one experiences depression as a result of low serotonin, a mood-stabilizing neurotransmitter in the brain.

Risk Factors for Depression

While they don’t cause depression, there are a number of factors that can put you at an increased risk of developing depression. These include:

  • History of other forms of mental health conditions, such as an anxiety disorder
  • Surviving a traumatic event
  • Having long-standing personality characteristics including lower self-esteem or pessimistic tendencies
  • Identifying as lesbian, gay, bisexual or transgender, and experiencing an environment that is unsupportive (including harassment, abuse, rejection, isolation)
  • Having a biological family member(s) with a history of mental illness
  • Abusing alcohol or other drugs
  • Having a serious or chronic illness (e.g. cancer, diabetes, stroke, and chronic pain)
  • Being in an unhealthy relationship or a stressful work environment without a clear end or change in sight
  • Taking certain medications (talk to your doctor before discontinuing or changing any prescribed medications)

Treatment Options for Depression

It is important to keep in mind that just as no two people are exactly alike, treatment for depression can look quite different from person to person. What may work for one person may not be the solution for another.

If you are looking for a depression treatment plan for yourself or someone close to you, you don’t have to do it alone. Working with a qualified medical or mental health professional (or a combination of the two) can help you find the right solution for you.

Individual Therapy for Depression

Individual therapy (or “talk therapy”) is a form of treatment where individuals work one-on-one with a trained mental health professional to learn how to deal with negative thought patterns, feelings, and behaviors.

The personal insight and skills taught in these sessions have the potential to not only ease depression, but also help to prevent a relapse.

The typical length of time for therapy for depression is 12-16 weekly sessions, but the number of sessions varies based on the complexity of the depression, the therapist’s style, and other variables.

In therapy for depression, the goal is to identify your unique negative thought patterns that are triggering depressive feelings, and then utilize certain skills to change those patterns to ultimately feel (and think) better.

You will be guided to self-reflect in order to identify the specific negative thoughts that are triggering the depression. In doing so, you can learn when and how negative emotions occur so you can take appropriate steps when needed.

Talk therapy can come in many styles when it comes to treating depression, but the approaches listed below are the most common and have the most evidence showing that they work:

  • Cognitive-Behavioral Therapy (CBT): A shorter-term form of therapy that helps clients to challenge and overcome thought patterns that can lead to depression and can help them to engage in more constructive and pleasurable behaviors.
  • Dialectic Behavioral Therapy (DBT): A skills-based therapy that includes mindfulness, regulating emotions and distress, as well as improving interpersonal skills.
  • Acceptance and Commitment Therapy (ACT): A style of therapy that focuses on “psychological flexibility,” mindfulness, and accepting (rather than challenging) negative thoughts.
  • Mindfulness-Based Stress Reduction (MBSR): A shorter-term (typically 8 weeks) form of therapy that blends mindfulness, yoga, meditation, body awareness, and looking into patterns of thoughts, feelings, and actions that hold us back from successfully getting in touch with our sense of well-being.

Keep in mind that when you are in a therapy session, in order for it to be effective, it is incredibly important for you to be completely honest, to come consistently to sessions, and to be willing to do the work.

It is with frank and open discussions that you will be able to move forward and break out of your depressive hold. You will likely also see improvements faster if you are willing to engage in therapy homework between sessions.

For some, finding the right therapist can be a bit of a challenge. Here are some variables to consider when searching for a therapist:

  • Credentials: Therapists can hold a number of different degrees. Masters-level clinician degrees include Licensed Clinical Social Workers (LCSW), Licensed Marriage and Family Therapists (LMFT), and Licensed Professional Clinical Counselors (LPCC). Doctoral-level clinician degrees include Licensed Doctor of Clinical Psychology (PsyD) and Licensed Doctor of Philosophy (PhD). To look up a therapist’s license, consult the therapist’s state licensing board website.
  • Fees: It’s a good idea to ask about fees prior to scheduling your first session. Therapy out of pocket can be expensive (i.e. $100-$300 per 45-minute session, depending on location, experience, and expertise). Not all therapists take insurance. If you wish to use insurance or employee assistance program (EAP), contact your insurance company or EAP for a list of in-network therapists. If a prospective therapist is an out-of-network provider, ask if he or she can provide you with a ”Superbill” that you can submit to your insurance company for potential reimbursement. If not, ask the therapist if he or she offers a “sliding scale” that can reduce your cost depending on your income level. If none of those options are available, and you’re concerned about the cost of therapy, seek out a supervised intern/resident or a community clinic that may be funded by a government grant, etc.
  • Style of Therapy: As mentioned above, there are a number of different styles or “theoretical orientations” of therapy (including numerous additional styles not listed above). You are encouraged to ask your therapist what style they offer (or read about them online) to ensure it is “evidence-based.”
  • Right Fit: Other variables to consider include gender preference, cultural, ethnic, or religious preference, experience/expertise, the estimated length of treatment, location (including in-office vs. online/video-based therapy), therapeutic “chemistry” and personality matches.

Feel free to “shop around” to find a provider you feel you can trust, who is non-judgemental, and skilled in treating your depression. If you are not satisfied with the services or style of the first therapist you meet, it’s okay to seek out another provider. A nice starting point for finding a therapist is on the Psychology Today directory. There, you can search for a provider by location, specialty, gender, and style, and you can find therapist biographies.

Psychiatric Medications for Depression

Psychiatric medications are sometimes used in conjunction with therapy for the treatment of depression. Some people choose to try medication without individual therapy. While not optimal, it can be practical for many sufferers, and it can work more quickly than therapy alone.

However, this approach doesn’t help to address what is driving the depression. Psychiatric medications are typically prescribed by primary care physicians (PCP) or psychiatrists.

It’s not uncommon for individuals who have never taken psychiatric medications to talk to their PCP about starting on an antidepressant prior to being referred to a psychiatrist, and you can do this in the K Health app.

It’s important to note that many people on medication experience uncomfortable side-effects (such as weight gain, sexual problems, nausea, or allergic reactions) that can accompany this form of treatment, and it’s important to work through these issues with your doctor.

I won’t cover all of the possible medications your doctor may prescribe, however, below is a list of the more commonly prescribed antidepressants:

  • Selective Serotonin Reuptake Inhibitors (SSRIs): This class of medication includes drugs like Zoloft, Prozac, Sarafem, Celexa, Lexapro, Paxil, Pexeva, Brisdelle, and Luvox. Doctors prescribe SSRIs when they believe that your depression is a function of an imbalance in serotonin levels in the brain.
  • Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs): This class of medication affects levels of serotonin and norepinephrine in the brain. The most commonly prescribed drugs in this category include Pristiq, Khedezla, Cymbalta, Fetzima, and Effexor XR. These drugs are sometimes prescribed when depression is accompanied by chronic pain, which can either be contributing to the depression or making it worse.
  • Tricyclic Antidepressants: (TCAs): These are older drugs that are usually the go-to option for those who can’t tolerate the negative side effects of SSRIs and SNRIs. They include drugs like amitriptyline, amoxapine, clomipramine, doxepin, imipramine, nortriptyline, protriptyline, and trimipramine.
  • Dopamine Reuptake Blockers: Medications that fall into this class include Wellbutrin, Forfivo, and Aplenzin. These are milder forms of medication and commonly are used to treat seasonal depression.

There are, of course, other medications that are commonly (or less-commonly) prescribed. These alternatives are often prescribed when an individual is not responding well to first-line antidepressants, or when dealing with multiple psychiatric conditions at a time. Again, since not everyone’s chemistry is the same, at times you may need to “try” a variety of different medications to find the ones for which your body’s chemistry is best suited.

Self-Help Resources for Depression

We live in a world where information about any and everything can be easily found. The same is true for depression. We have created an article about Self-Help Tips for Depression.

For additional information about depression and the different forms of treatments offered, here are some highly recommended and informative books and apps to consult.

Books for Depression

Feeling Good: The New Mood Therapy
By David D. Burns
Feeling Good is the gold standard cognitive-behavioral therapy self-help book for depression. The book has an extensive list of exercises to help conquer negative thoughts and overcome negative feelings.

The Happiness Trap: How to Stop Struggling and Start Living: A Guide to ACT
By Russ Harris
The Happiness Trap focuses on improving depression through acceptance and commitment therapy. With these tools, you can clearly lay out your values and pursue them through committed action and mindfulness.

Mind Over Mood, Second Edition: Change How You Feel by Changing the Way You Think
By Dennis Greenberger and Christine A. Padesky
Mind Over Mood offers a number of CBT and mindfulness therapy techniques and exercises to help you improve your depression.

The Mindful Way Through Depression: Freeing Yourself from Chronic Unhappiness
By Mark Williams, John Teasdale, Zindel Segal, and Jon Kabat-Zinn
The Mindful Way Through Depression teaches its readers how to systematically use mindfulness to break the cycle of their depression.

Disarming the Dark Cloud

Mental illness can feel like a scary topic, but it doesn’t have to be. Educating yourself on the symptoms, triggers, self-help options and when to seek treatment can help you prevent a significant episode in the future. Be aware that once you have had a major depressive episode, you are susceptible to having another one—so be diligent in your fight against negative thoughts and seek help when needed.

If you or someone you know is experiencing thoughts of suicide, it is recommended that you call 911, go to the nearest emergency room, or call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255). If you are feeling depressed and unsure if you should seek help, consider talking to your primary care physician, a loved one, or a friend who you can confide in about what you have been going through.

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How K Health Can Help

Anxiety and depression are among the most under-reported and under-treated diseases in America. Nearly 20% of adults in the US suffer from mental health illness and fewer than half receive treatment. Our mission is to increase access to treatment for those suffering in silence.

You can start controlling your anxiety and depression and get access to the treatment you need with K Health. Starting at $12/month get prescriptions for mental health medications plus unlimited doctor visits through the K Health app. Start your free assessment here.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Ross Nelson, PsyD

Dr. Ross Nelson is a licensed clinical psychologist and entrepreneur in Palo Alto, CA. He received his doctorate from the California School of Professional Psychology, and has professional expertise in cognitive behavioral therapy. He has worked in outpatient services at Kaiser Permanente, and as a psychologist for the startup, Crossover Health. Today, Dr. Nelson runs a private practice and is also the founder of Welleo Health. He is passionate about evidence-based therapy and addressing the global mental health crisis.