Cognitive Behavioral Therapy (CBT) began in the 1960s, when psychiatrist Aaron Beck noted that many “depressed patients experienced streams of negative thoughts that seemed to arise spontaneously. He called these cognitions “automatic thoughts.” He found that the patients’ automatic thoughts fell into three categories.
The patients had negative ideas about themselves, the world and/or the future. Dr. Beck began helping patients identify and evaluate these automatic thoughts. He found that by doing so, patients were able to think more realistically. As a result, they felt better emotionally and were able to behave more functionally.
When patients changed their underlying beliefs about themselves, their world and other people, therapy resulted in long-lasting change. Dr. Beck called this approach “cognitive therapy.” It has also become known as ‘cognitive behavior therapy.’ ” 
In 1979, Beck published Cognitive Therapy of Depression  a combination of his study results and treatment protocol manual. Since that time, many other clinicians have studied and developed CBT treatment protocols looking at the effect on many different types of psychiatric disorders.
Three Aspects of Cognition
CBT is based on a model of the relationships among cognition, emotion, and behavior. This model is nicely outlined by Chand and Whitten in Stat Pearls  as follows:
Three aspects of cognition are emphasized:
- Automatic Thoughts
An individual’s immediate, unpremeditated interpretations of events are referred to as automatic thoughts. Automatic thoughts shape both the individual’s emotions and their actions in response to events. For example, a friend may cross you in the hallway and not say hello to you. If you were to have an automatic thought of "he hates me," or "I have done something to anger him,"
it is likely to impact your mood and cause you to feel upset and also to behave in an avoidant manner when you see him next. On the other hand, if you had the automatic thought "he is in a hurry," you would not be too concerned, and you would not be avoidant when you were to see him next.
CBT is based on the observation that dysfunctional automatic thoughts that are exaggerated, distorted, mistaken or unrealistic in other ways play a major role in psychopathology.
- Cognitive Distortions
Errors in logic are quite prevalent in patients with psychological disorders. They lead individuals to erroneous conclusions. Below are some cognitive distortions that are commonly seen in individuals with psychopathology:
- Dichotomous thinking: Things are seen regarding two mutually exclusive categories with no shades of gray in between
- Overgeneralization: Taking isolated cases and using them to make wide generalizations
- Selective abstraction: Focusing exclusively on certain, usually negative or upsetting, aspects of something while ignoring the rest
- Disqualifying the positive: Positive experiences that conflict with the individual’s negative views are discounted
- Mind reading: Assuming the thoughts and intentions of others
- Fortune telling: Predicting how things will turn out before they happen
- Minimization: Positive characteristics or experiences are treated as real but insignificant
- Catastrophizing: Focusing on the worst possible outcome, however unlikely, or thinking that a situation is unbearable or impossible when it is really just uncomfortable
- Emotional reasoning: Making decisions and arguments based on how you feel rather than objective reality
- “Should” statements: Concentrating on what you think "should" or “ought to be” rather than the actual situation you are faced with or having rigid rules which you always apply no matter the circumstances
- Personalization, blame, or attribution: Assuming you are completely or directly responsible for a negative outcome. When applied to others consistently, blame is the distortion
- Underlying Beliefs
Underlying beliefs shape the perception and interpretation of events. Belief systems or schemas take shape as we go through life experiences. They are defined as templates or rules for information processing that underlie the most superficial layer of automatic thoughts. Beliefs are understood at two levels in CBT:
- The central ideas about self and the world
- The most fundamental level of belief
- They are global, rigid, and overgeneralized
Examples of dysfunctional core beliefs:
- “I am unlovable.”
- “I am inadequate.”
- “The world is a hostile and dangerous place.”
- Consist of assumptions, attitudes, and rules
- Influenced in their development by the core beliefs
Examples of dysfunctional intermediate beliefs:
- “To be accepted, I should always please others.”
- “I should be excellent at everything I do to be considered adequate.”
- “It is best to have as little as possible to do with people.”
Steps in CBT
CBT is usually tailored to the patient’s specific disorder and situation and includes these steps:
- Identify troubling situations or conditions in your life. Decide which ones to focus on.
- Become aware of your thoughts, emotions, and beliefs about these problems. Keeping a journal of your thoughts is often advised.
- Identify negative or inaccurate thinking. Instructed to pay attention to your physical, emotional and behavioral responses to various situations.
- Reshape negative or inaccurate thinking. This often takes time and practice.
CBT is generally considered short-term therapy — typically lasting about 10 to 20 sessions.
Is There any Research?
CBT is the most researched form of psychotherapy.  A review of PubMed revealed 86,066 articles. There are 21,520 review articles and 17,202 labeled as clinical trials. There are 1371 studies on ClinicalTrials.gov.
To put this into perspective, there are 17,056 articles in PubMed that look at psychoanalytic therapy, with 1291 review articles and 233 clinical trials. There are only 4 studies on ClinicalTrials.gov.
Does Cognitive Behavioral Therapy Lower Symptoms of Depression?
As mentioned in the previous section, CBT has been extensively studied, and there are over 18,000 studies in PubMed that look at the use of CBT in depression. Most have found that CBT has at least a moderate effect on the level of depression.
However, the studies are very heterogeneous: they use a variety of CBT methods, look at different populations (youth, teens, adults, elderly, veterans ), are done on individuals or in a group setting, in otherwise healthy individuals or in those with other medical disorders , and the use CBT alone or with pharmacologic intervention. Some even look at internet-based CBT.
Most clinical trials compare CBT with a “control condition” in the acute treatment of these disorders. Control conditions in studies like these include “waiting list”, “care-as-usual” or more conventional pill placebo controls. A “waitlist control group” is a group of participants included in an outcome study that is assigned to a waiting list and receives intervention after the active treatment group.
“Care-as usual” (also called treatment-as-usual or TAU) is a term used to describe the full spectrum of patient care practices in which clinicians can use to individualize care.
This can include medication, psychotherapy or a combination of the two. Some researchers have questioned whether these types of control conditions can lead to erroneous conclusions about the effect of CBT. Furukawa et al  did a meta-analysis of randomized controlled trials using CBT for depression.
They specifically looked at the control conditions used in the studies which included waiting list (WL), no treatment (NT) and psychological placebo (PP). They found that the effect size estimates for CBT “were substantively different depending on the control condition.” Watts et al  did an analysis of CBT vs treatment-as-usual for anxiety and depression.
They found “CBT is superior to TAU and the size of the effect of CBT compared to TAU depends on the nature of the TAU condition’ and added, “The term TAU is used in different ways and should be more precisely described.”
Keeping these potential limitations in mind, let’s look at just a few of the studies done on the use of CBT in depression. A 2016 meta-analysis by Cuijpers et al  looked at 144 trials using CBT for the treatment of major depression (MDD), generalized anxiety disorder (GAD), panic disorder (PAD) and social anxiety disorder (SAD).
They concluded that “CBT is probably effective in the treatment of MDD, GAD, PAD and SAD; that the effects are large when the control condition is waiting list, but small to moderate when it is care-as-usual or pill placebo; and that, because of the small number of high-quality trials, these effects are still uncertain and should be considered with caution.”
A meta-analysis by Feng et al  found that “group-based CBT was more effective than control interventions but this effect did not persist beyond six months.”
A review by Tolin  looked at 26 randomized controlled trials of CBT vs. another form of psychotherapy. He concluded that CBT was superior to psychodynamic therapy at post-treatment and at follow-up.
A large Australian cohort study by Vos et al  found that CBT and pharmacological treatments had similar effects on chronic depressive symptoms but that “longer-term maintenance drug or psychological treatment strategies are required to make significant inroads into the large disease burden associated with major depression.”
A 2018 study by Furukawa et al  evaluated three randomized controlled studies (with over a thousand participants). They found that “On average, the combination therapy showed significant superiority over both monotherapies in terms of efficacy and acceptability, while the latter 2 treatments showed essentially similar results.”
CBT is the most researched type of psychotherapy and has been found to have a positive effect in the treatment of depression. The magnitude of this effect is difficult to assess due to problems with the most frequently used control conditions. Use of CBT as an adjunct to pharmacologic therapy may be more effective than either modality alone.
There is mixed data on how long the effects of CBT last and prolonged or intermittent treatment may be necessary in some patients.
Does Cognitive Behavioral Therapy Reduce Anxiety?
According to the World Health Organization, there are over 24.6 million people worldwide who suffer from anxiety disorders. The National Institute of Mental Health estimates that about ⅓ of U.S. adults experience anxiety disorder at some time in their lives.
Anxiety disorders can be manifested in a variety of ways:
- Panic disorder
- Obsessive-compulsive disorder (OCD)
- Post-traumatic stress disorder (PTSD),
- Social phobia (or social anxiety disorder)
- Specific phobias
- Generalized Anxiety Disorder (GAD)
Patients with anxiety frequently engage in a number of the cognitive distortions (listed above), especially overgeneralization, catastrophizing and low self-confidence. Automatic thoughts cause a cycle of worry, avoidance, and procrastination. Excessive worry can also cause autonomic arousal with elevated heart rate, sweating, motor tension, etc.
Proponents of CBT point out that it is designed to address many of the various cognitive, behavioral and physiological features of anxiety disorders. How well does it work? Let’s look at some of the scientific studies done.
Kristin Mitte  did a meta-analysis of the efficacy of CBT for generalized anxiety disorder (GAD) compared to the efficacy of pharmacologic therapy. Thirteen studies comparing CBT to control groups and 6 comparing CBT with pharmacotherapy (involving 869 patients) were included in the analysis.
She concluded that “The results of the present meta-analysis indicate that (C)BT is a highly effective treatment of GAD, reducing not only the main symptoms of anxiety but also the associated depressive symptoms and subsequently improving quality of life.”
However, she points out that the effect sizes may overestimate the real effect of the treatment, because patients who dropped out of the studies were excluded. The results of the comparison between (C)BT and pharmacotherapy varied according to the meta-analytic methods used.
When only those studies that directly compared both therapies were included in the analysis, there were no significant differences in efficacy. Carpenter et al  also did a meta-analysis of 41 randomized placebo-controlled trials (N= 2843 patients) using CBT for a variety of anxiety related disorders including acute stress disorder, generalized anxiety disorder (GAD), obsessive-compulsive disorder (OCD), panic disorder (PD), posttraumatic stress disorder (PTSD), or social anxiety disorder (SAD). CBT was compared to either a psychological or pill placebo control condition.
They concluded that CBT is a moderately efficacious treatment for anxiety disorders when compared to placebo. “Large effect sizes were found for OCD, GAD, and acute stress disorder, and small to moderate effect sizes were found for PTSD, SAD, and PD. In PTSD studies, dropout rates were greater in CBT (29.0%) compared to placebo (17.2%), but no difference in dropout was found across other disorders.”
Like Mitte, they found that effects where larger when only patients who completed the treatment course were included vs studies where all patients who started treatment were included. They also found that the effects were stronger for individuals compared to group CBT in SAD and PTSD studies.
Lastly, Porto et al  did a systematic review of neuroimaging studies in anxiety disorders. Looking at 10 studies that used functional magnetic resonance (fMRI) or positron emission tomography (PET) on patients before and after treatment with CBT. The reviewers found that there were a number of subcortical and cortical regions associated with the successful treatment of anxiety disorders with CBT.
Although the results were not uniform (due to different methodologies) key limbic and cortical structures were identified. Perhaps as interesting is that these areas are similar to the ones affected by medications used to treat the same conditions, suggesting a common way of brain modification.
Cognitive Behavioral Therapy has been found to be effective in the treatment of anxiety disorders, although it has a greater effect in some types (such as GAD and OCD) than others (PD, PTSD). There are a growing number of styles and specific techniques being “housed” under the tent of CBT and some may work better for some patients than for others. Additional scientific evaluation of some of the newer techniques is needed.
Does Cognitive Behavioral Therapy Help Treat Eating Disorders?
The term “eating disorders” encompasses a range of disorders, the most common of which are anorexia nervosa (AN), Bulimia nervosa (BN) and binge-eating disorder (BED). According to the National Association of Anorexia Nervosa and Associated Disorders (ANAD) at least 30 million people of all ages and genders suffer from an eating disorder in the United States.
In addition, every 62 minutes at least one person dies as a direct result from an eating disorder.
Anorexia nervosa (AN) is characterized by emaciation, a relentless pursuit of thinness and unwillingness to maintain a normal or healthy weight, a distortion of body image and intense fear of gaining weight, a lack of menstruation among girls and women, and extremely disturbed eating behavior. Some people with anorexia lose weight by dieting and exercising excessively; others lose weight by self-induced vomiting, or misusing laxatives, diuretics or enemas.
Firstline treatment of AN, as recommended by the American Psychiatric Association , consists of nutritional rehabilitation plus psychotherapy with the goal of weight restoration.
Depending on the severity of the disease, initial treatment may occur as an inpatient or outpatient. Nutritional therapy includes supervised meals, monitoring food intake, etc. Several forms of psychotherapy, including CBT, family therapy, and group therapy, have been recommended.
In 2009, Wild et al  outlined the Anorexia Nervosa Treatment of OutPatients (ANTOP) trial, which compared CBT, psychodynamic psychotherapy and usual care in 242 patients. The study lasted 10 months, and patients were evaluated 1 year after completing treatment. The results of this study were published in Lancet in 2014 .
Improvement in body mass index (BMI) was comparable for the three groups at approximately 1.4kg/m2. Enhanced CBT (tailored to eating disorders) was more effective with respect to the speed of weight gain and improvements in eating disorder psychopathology.
Fairburn et al  enrolled 99 adult patients with marked AN recruited from consecutive referrals to clinics in the UK and Italy. Each was offered 40 sessions of CBT-E over 40 weeks. Sixty-four percent of the patients were able to complete this outpatient treatment and in these patients, there was a substantial increase in weight and BMI. Eating disorder features also improved markedly.
Over the 60-week follow-up period, there was little deterioration despite minimal additional treatment.
It should be noted that CBT is listed as one of the recommended psychological treatments for first-line therapy in the treatment of AN by NICE (National Institute for Health and Care Excellence) based in the UK. The other two modalities were the Maudsley Anorexia Nervosa Treatment for Adults (MANTRA) and specialist supportive clinical management (SSCM) .
As mentioned above it is also recommended by the American Psychiatric Association .
Bulimia is an illness in which a person binges on food or has regular episodes of overeating and feels a loss of control. The affected person then uses various methods — such as vomiting or laxative abuse — to prevent weight gain. Usually, bulimic behavior is done secretly, because it is often accompanied by feelings of disgust or shame.
The case for the use of CBT in the treatment of BN is a little stronger than for anorexia. Shapiro et al  in a review of 47 randomized control trials (RCT) using medication only, behavioral interventions only, or medication plus behavioral interventions for patients with BN.
They concluded that “fluoxetine (60 mg/day) decreases the core symptoms of binge eating and purging and associated psychological features in the short term. Cognitive behavioral therapy reduces core behavioral and psychological features in the short and long term.”
A paper by Hay et al  published in the Cochrane Database of Systematic Reviews (a leading journal and database for systematic reviews in health care) also evaluated 48 RCTs with a total of 3054 participants. The review supported the efficacy of CBT and particularly CBT-BN in the treatment of people with bulimia nervosa.
As with AN, NICE recommends CBT for adults with BN- typically 20 sessions over 20 weeks. It is also recommended by the American Psychiatric Association  saying “CBT specifically directed at the eating disorder symptoms and underlying cognitions in patients with bulimia nervosa is the psychosocial intervention that has been most intensively studied in adults and for which there is the most evidence of efficacy.”
Binge Eating Disorder (BED) is characterized by recurrent episodes of eating large quantities of food (often very quickly and to the point of discomfort); a feeling of a loss of control during the binge; experiencing shame, distress or guilt afterwards; and not regularly using unhealthy compensatory measures (e.g., purging) to counter the binge eating.
As a result, people with binge-eating disorder are often overweight or obese. BED is the most common eating disorder in the United States. About 3.5 percent of adult women and 2 percent of adult men have binge eating disorder. For men, binge eating disorder is most common in midlife, between the ages of 45 to 59.
Once again, CBT (especially CBT specialized for eating disorders) is recommended as a first-line therapy in the treatment of BED by NICE and the American Psychiatric Association .
Two recent articles that support these recommendations are by Grillo  and Ghaderi et al . Grillo’s is a review of psychological and behavioral treatments for BED. He reports that CBT (and interpersonal psychotherapy-IPT) “reliably produce both short- and long-term reductions in binge-eating (>50% remission rates) … [however] they do not produce weight loss.”
Ghaderi’s is a systematic review and meta-analysis of psychological, pharmacological, and combined treatments for binge-eating disorder. They found “45 unique studies with low/medium risk of bias, and moderate support for the efficacy of cognitive behavior therapy (CBT) and CBT guided self-help (with moderate quality of evidence).
CBT is considered a recommended option for the treatment of most eating disorders. The evidence is strongest for BN and BED, with less effect on patients with AN. As with many studies done for psychological treatments they be skewed (in varying degrees) by method bias and types of control conditions and patient inclusion criteria.
Does Cognitive Behavioral Therapy Reduce Addictive Behaviors and Substance Abuse?
Addictive behaviors can include a very broad range of activities- from drug abuse, cigarette smoking, gambling, and even internet and mobile phone addictions.
Addiction is defined as a chronic, relapsing disorder characterized by compulsive drug or “activity” seeking, continued use despite harmful consequences, and long-lasting changes in the brain chemical systems and circuits, which include:
Therefore, it is considered both a complex brain disorder and a mental illness. As such it may require both medical and psychological interventions to treat.
Clinical trials of CBT as an adjunct to methadone in opioid addiction have had mixed results. Scherbaum et al  randomly divided 73 opioid-dependent patients into two groups- one which received methadone plus 20 weeks of group CBT, the other- methadone plus treatment as usual (weekly counseling).
After 20 weeks of treatment, there was no difference between the two groups in the rate of negative urine tests. However, at the 6-month follow-up, the CBT group had a lower rate of positive urine drug tests.
Moore et al  looked at 140 opioid and heroin patients who received either physician management (PM) consisting of buprenorphine and naloxone alone or with CBT. They found that “Primary prescription opioid use patients assigned to PM-CBT had more than twice the mean number of weeks of abstinence for all drugs than those assigned to PM only, while primary heroin use patients did not differ by treatment.
Carroll et al  reevaluated 120 patients treated for cocaine dependence up to 1 year after receiving CBT and pharmacotherapy. They found that those who received CBT did better over time than those with clinical management alone.
Their findings suggest a delayed emergence of the effects of cognitive-behavioral relapse prevention, which may reflect the subjects' implementation of the generalizable coping skills conveyed through that treatment.
Spears et al  compared CBT with mindfulness-based addiction treatment (MBAT) and usual care (UC) in smoking cessation. Both CBT and MBAT groups did better than those receiving only UC. There was no significant difference between CBT and MBAT results.
CBT may be useful as an adjunct in the treatment of addictive disorders, especially in regard to decreasing the risk of relapse.
Does Cognitive Behavioral Therapy Help Improve Self-Esteem and Confidence?
According to CBT practitioners, low self-esteem and lack of self-confidence is the result of patients’ use of automatic thoughts, cognitive errors and dysfunctional core beliefs. Understanding these cognitive and behavioral errors is the basis of their treatment.
So, one would expect that CBT can improve self-esteem and confidence in those who undergo this therapy. However, there are not a lot of scientific studies which specifically address only these issues, especially in otherwise healthy people.
There are a few studies which found a positive effect of CBT on self-esteem and mood in patients with medical health disorders, such as heart failure in Filipino patients , overweight children with ADHD  and community-living Japanese patients with mental illness .
CBT may or may not have some positive effect on self-esteem and confidence. More studies are needed to reach a conclusion.
Is Cognitive Behavioral Therapy Safe?
In researching this section, I originally wondered how to write about the safety and side effects of psychological therapy. It’s easy to discuss the side effects of medications, but how do you define a side effect of psychotherapy and distinguish it from the illnesses they are designed to treat? As Nutt and Sharpe  put it, there is an “assumption …that as psychotherapy is only talking… no possible harm could ensue.”
But according to Berk and Parker  all effective treatments have a risk of adverse events, and that those found with psychotherapy are not necessarily insignificant. They point out that significant harm can be caused by inappropriate psychotherapy or by inappropriate psychotherapist behavior.
For example, “if psychotherapy is the only therapy for a condition for which it is either inappropriate or ineffective, the patient may be exposed to a lengthy period of ongoing symptoms and disability.” Likewise, an insensitive, critical or sexually exploitive therapist can put an already troubled and vulnerable patient at increased risk of poor outcome.
The biggest part of the problem is that, although there are many studies looking at efficacy, there are very few that are also looking for side effects. Linden and Schermuly-Haupt  point out several reasons for this:
- The psychotherapist is the “producer” of treatment and therefore responsible, if not liable, for all negative effects, which results in a perceptional bias towards positive rather than negative effects.
- Psychotherapy does not only focus on symptoms but also on social behavior, so that the spectrum of possible negative effects is much broader than in pharmacotherapy.
- There is even no consensus on what to call negative: for instance, when evaluating a manuscript on psychotherapy side effects, a reviewer wrote: “a divorce can be both positive and negative, and crying in therapy can reflect a painful experience but can also be a positive and therapeutic event.”
- There is a lack of differentiation between side effects and therapy failure or deterioration of illness.
- There are no generally accepted instruments for the assessment of psychotherapy side effects and no rules on how to plan scientific studies or monitor side effects in randomized controlled clinical trials.
A large study in the UK  attempted to quantitate the negative effects of psychological treatment. They sent surveys to people who were undergoing psychotherapy for common mental health disorders (primarily anxiety and mood disorders) through the National Health Service. Approximately 15,000 surveys were returned (about 20% of those who received them).
Five percent reported experiencing lasting bad effects. People over age 65 were less like to report negative effects, while those who were ethnic or sexual minorities were more likely to report them.
The above study did not differentiate the type of psychotherapy the participants received. Berk and Parker  discuss possible negative effects found in patients undergoing CBT. They point out that CBT assumes the participant has a certain level of reasoning capacity- which for some may be lacking due to low intelligence or current symptoms.
Not being able to meet the expectations of the therapy may have their sense of self-worth undermined. There is also a shift of responsibility onto the individual “for active engagement and conduct of the techniques. A recipient may feel guilty if treatment does not result in the expected improvements, without realizing that there are many other factors that may affect the response.
In addition, “Some experienced cognitive therapists suggest that CBT can be toxic to some individuals, particularly those with obsessive personalities, by increasing worry and introspection, fueling rather than relieving anxiety and depression.”
Although psychotherapies such as CBT are assumed to be safe, there is not a lot of specific evidence to support these claims. There is some risk of negative events with CBT. More research is needed in this regard and patients should be apprised of these risks.
CBT is a long-established model of psychotherapy, recommended by leading mental health care organizations. It has undergone exhaustive scientific scrutiny and usually is found to have a positive effect.
The magnitude of the effect can be difficult to assess due to several confounding factors such as small sample sizes, variations in the control conditions used, method bias by the study researchers, and grouping of CBT with several other psychotherapies (such as psychodynamic therapy, mindfulness therapy, etc).
New variations of CBT are being introduced, many in electronic form, which will need to undergo similar scientific scrutiny.