I. What is Depression?
The Medical Model
The American Psychiatric Association has conceptualized depression as a brain “disease,” and in its Diagnostic and Statistical Manual, a diagnosis of depression is to be made if a person has certain “symptoms” said to be characteristic of the disease. These symptoms include low mood, loneliness, feelings of guilt and worthlessness, and thoughts of suicide. Other “symptoms” include over-eating, not eating, over-sleeping, and not being able to sleep. A person does not need to have all, or even most, of the symptoms in order to be diagnosed with depression.
Thus, the individual experience of a depression diagnosis varies. For one person, it might mean feeling hopeless about the future, not sleeping, and over-eating; for another it might mean feeling isolated from others, not eating, and sleeping all day.
As it is conceived of as a disease, the treatment is focused on diminishing the symptoms, as opposed to assessing whether the treatment helps a person make changes in his or her life that might better promote well-being. Antidepressants are used as a first-line therapy for this purpose of reducing the symptoms of the disease.
The Psychosocial Model
Most psychosocial interventions conceive of depression differently. While there may be many physical causes that lead to the “symptoms” associated with depression, the understanding is that the context of a person’s life is also of primary importance. There are many difficulties in life that can lead a person to feeling depressed—divorce, loss of a job, social isolation, loss of a loved one, poverty, and so forth—and thus psychosocial interventions often focus on understanding that context, and making changes in one’s life to alter that context.
The Naturalistic Course of Depression
Before the widespread use of antidepressants, depression was understood to be an episodic disorder, and that most people could be expected to recover with time. This understanding came from studies of people who had been hospitalized for depression, and thus were “severely” depressed at the time of hospitalization. In such studies, 85% of patients would be discharged within one year. Fifty percent of all patients would recover and have only a single episode of depression (over the long-term); another 30 percent might have periodic bouts of depression (once every three years or so); and only 20% would become “chronically” depressed.
Today, in the antidepressant era, depression is understood to run a much more chronic course. In the large STAR*D study of people taking antidepressants, only about 26% of the 4041 patients who entered the study “remitted,” and at the end of one year, only 3% were still well and in the trial.
However, research studies in the antidepressant era that have charted outcomes for unmedicated patients have found outcomes similar to the natural recovery rate reported prior to the antidepressant era. This NIMH-funded study found that without medication, more than half (52%) of people with depression diagnosis got better within three months, while 85% no longer had the diagnosis after a year. Another naturalistic study found that of 356 people who no longer had the depression diagnosis at the end of the study, 217 (61%) of them achieved that feat without taking antidepressants. Yet another study found better remission rates without medication: over 10 years, 76% of those who did not take antidepressants recovered, and never relapsed.
This natural recovery may occur for many reasons: the passage of time alone may be a source of healing, and it may also be that the experience of depression may motivate people to discover and alter the causes of such suffering in their lives.
Antidepressants and other Somatic Treatments
Since the medical model conceptualizes depression as a disease, clinical trials assess “efficacy” of a treatment by assessing whether they reduce the “symptoms” of the disease. In trials funded by pharmaceutical companies, antidepressants have been found to reduce symptoms slightly better than placebo, although the difference is not seen as clinically significant. Long-term studies suggest that antidepressants increase the risk that a person will become chronically depressed and functionally impaired. (SEE LINK TO DRUG PAGE FOR DEPRESSION.)
There are other interventions besides medication that are based on a neurological paradigm. These interventions include controversial treatments such as electro-convulsive therapy (ECT), trans-cranial magnetic stimulation (TMS), trans-cranial direct current stimulation (tDCS), and experimental drugs such as ketamine. There is no good evidence that any of these treatments provide a reduction of symptoms that lasts beyond a month, and with both ECT and ketamine, there are many possible adverse effects.
Research on psychosocial interventions is often muddied by the concurrent use of antidepressant medications. In general, however, rigorous reviews of studies of psychosocial therapies, such as this one and this one, have found that most, if not all, psychosocial interventions are at least as effective as medications for depression, but without the adverse effects common with antidepressants. There is some evidence that long-term outcomes may also be better with psychosocial interventions than with antidepressants, although such studies don’t provide a comparison with long-term outcomes for depressed people who avoid treatment altogether.
A broad range of psychotherapies exist. The focus of a therapy may be on an individual’s skill-building, such as how to cope with stressful situations or life transitions. Other therapies focus on making life changes or on improving relationships with family and peers. Some therapies combine different aspects of each of these domains.
The way psychotherapy is studied may also vary. Some therapies are researched as universal approaches, where a therapist follows a manual. These are usually studied in terms of how well they reduce “symptoms” on a depression scale—the same way antidepressants are studied.
However, other therapies are tailored, individual approaches. When studied, researchers of these therapies may focus more on client satisfaction, achievement of life goals, or overall quality of life as more important metrics, rather than simple symptom reduction.
A. Individual Symptom-Focused Therapies
These types of intervention are based on improving an individual’s ability to cope with stressful situations or change aspects of their thoughts or behavior. They mostly focus on individual symptom reduction, similar to antidepressants. However, they permit a wider understanding of the causes of distress.
1. Cognitive-Behavioral Therapy (CBT)
CBT is one of the long-standing, evidence-based treatments for depression, whether in adults or in youths. It involves a focus on changing “irrational” thoughts and behaviors through active, problem-solving processes. That is, CBT attempts to change “false beliefs” about the world to enable better emotional health. For the treatment of depression, one example would be attempting to alter a belief that one is a failure, and replacing it with the belief that one can make mistakes and fail at certain things without it making the entire person worthless.
CBT is well-studied, with decades of research finding positive effects on the improvement of depressive symptoms. Reviews generally demonstrate that it is about as effective as other approaches, such as psychodynamic therapy and interpersonal therapy, indicating that it is not the only evidence-based psychotherapy—contrary to how it is commonly described.
CBT has also shown success with depressive symptoms that have not yet responded to other treatments, with a review of research suggesting that it has better mid- and long-term effectiveness than pharmaceuticals for people classed as “treatment-resistant.”
A recent review of patients with cardiovascular disease also found that CBT was effective at reducing both depression and anxiety, as well as “mental health quality of life.”
Internet-based CBT also appears to be effective for reducing depression, even in cases rated as “severe.” However, the number-needed-to-treat (NNT) in that study was eight, indicating that eight people would need to receive the intervention for any one person to improve.
A Cochrane review also found that CBT is effective for the treatment of anxiety, and that internet-based CBT appears to be just as effective.
Another review suggested that CBT is as effective as other therapies, but not necessarily more effective. That same review also found that CBT has a higher drop-out rate than other therapies, most likely indicating that people find CBT less tolerable than other therapies.
2. Coping with Depression (CWD) Course
The CBT-based “Coping with Depression” (CWD) course has been studied for depression prevention (see above). However, CWD has also been studied for the treatment of people with a diagnosis of depression. CWD is variously described as a “multi-modal group psychoeducational” intervention and a “highly structured cognitive-behavioral intervention.”
Consistent with the results of the “prevention” studies, a review found that CWD improves “depressive symptoms,” especially for youth and elderly populations. However, the intervention did not appear to be effective for “minority groups.” The review included 18 studies, and resulted in the conclusion that CWD is just as effective as other therapies for the treatment of depression.
Another review found that the benefits may be short-term only, with differences between the intervention and control groups disappearing by the one-year follow-up.
3. Behavioral Activation
Behavioral activation (BA) is based on the theory that depression is a self-sustaining cycle: as people begin to feel depressed, they isolate themselves and pull away from previously-enjoyed activities, which makes them feel more depressed. In this therapy, people are encouraged to engage in activities and social connection, even if they don’t feel like it. According to the theory, this serves to help resolve depressive experiences by reinforcing that pleasurable experiences are possible.
Although the studies included were described as methodologically low-quality, short-term studies, a review found that BA was significantly better than medication for improving depressive symptoms.
A Cochrane review of various behavioral interventions, including BA, found that it appears to be as effective as other psychosocial interventions for depression. However, they note that the quality of the evidence was “very weak,” especially when compared to CBT, with its large evidence base.
Another review of the research found, similarly, that BA is as effective as other types of psychotherapy.
4. Acceptance and Commitment Therapy (ACT)
ACT is based on similar ideas to CBT, but with a functional, rather than mechanistic, approach. That is, ACT focuses on whether thought processes or behaviors are effective for a person navigating their environment, not whether they are “irrational” or “false.” ACT puts primacy on being able to work toward one’s life goals while being true to one’s values, whether there are “irrational” beliefs present or not. Thus, a focus of ACT includes mindfulness approaches of being present-centered and engaging in valued action, rather than ruminating about past events or worrying about the future.
Reviews of ACT for adults with depression generally find that it is at least as effective as other psychological interventions, such as CBT, and more effective than treatment-as-usual. However, there is very little long-term follow-up data to suggest whether effects are maintained over time.
For more information about ACT and its effectiveness, see the article available here.
5. Problem-Solving Therapy
Problem-solving therapy (PST) is a specific type of CBT intervention. Unlike broad thought- and behavior-based CBT, this therapy focuses on developing “skills” for identifying and solving “problems” in a one’s life.
A review of the research on PST found that it was as effective as other psychotherapy styles. That same review found that people were less likely to drop out of this type of therapy than other types. This indicates that people found the therapy process tolerable and wanted to continue.
Another review found the same, while indicating that it was most effective when manualized to include all aspects of the therapy—training in how to approach and view problems, and specific skills for generating alternatives and decision-making, in addition to simple “problem-solving skills.”
6. Mindfulness-Based Stress Reduction (MBSR) and Mindfulness-Based Cognitive Therapy (MBCT)
MBSR uses mindfulness meditation as a core element in therapy. The theory involves the use of attention regulation to reduce rumination and improve responses to stressors. MBCT adds cognitive techniques in addition to mindfulness.
Although the quality of MBSR studies has been questioned due to just a few small studies, lack of comparison groups, and other methodological limitations, the evidence in general supports its use for a variety of psychological indications, including experiences classed as depressive and anxious.
One study investigated people who had recently recovered from depressive symptoms. The researchers explored which group would have better outcomes: MBCT plus support for discontinuing medications, or maintaining medications only. They found that the people who were given MBCT were more likely to discontinue their antidepressant medications, and less likely to have a relapse of depression. In this regard, MBCT appeared far superior to antidepressants.
Another study looked at MBCT for people classed as having chronic depression (many of whom were taking antidepressant medications without recovering). MBCT was highly successful. Although there was no comparison group, the average improvement on the Beck depression inventory (BDI) was 10.4 points, and a full 20 (43%) of the participants remitted from their chronic depression.
A pilot study that did not include a comparison group also found that MBCT was effective for reducing anxiety as well.
A review noted the methodological shortcomings in the MBCT literature. Further research following the randomized, controlled trial design could help clarify some of these findings. However, the preliminary evidence is good in favor of this intervention.
7. Supportive Psychotherapy
This type of individual therapy is based on the client-centered model and involves a non-directive way of helping people to increase awareness of their emotions and problem-solve stressful life events.
A review of the research found that supportive therapy was less effective at treating depressive symptoms than other therapies, although it did still have an improving effect.
In one analysis of the studies (which also found supportive therapy less effective) the researchers suggested that allegiance effects could be responsible: supportive therapy was often used as a comparator against the personal pet therapy of the researcher. According to this theory, supportive therapy could be just as good, but few researchers focus on trying to make it look good. Still, that theory is difficult to prove.
Supportive psychotherapy, in sum, appears to be effective at improving overall well-being, but perhaps less so than other therapies.
8. Relaxation Therapy
An intervention that is designed to physiologically relax the client, usually targeted toward older adults.
A review of studies of relaxation therapy included progressive muscle relaxation, yoga, and music therapy. The study found that these interventions effectively reduced depressive symptoms in older adults.
Although there is limited research on it, music therapy specifically with a relaxation component has shown a positive effect on reducing depressive symptoms in older adults, making it a promising intervention for this population.
A Cochrane review of various behavioral interventions, including relaxation therapy, found that it appears to be as effective as other psychosocial interventions for depression. However, they note that the quality of the evidence was “very weak,” especially when compared to CBT, with its large evidence base.
B. Interpersonal Therapies
These interventions are based on the idea that the way people communicate with others leads to problems in their lives. They focus on individual skills, but only in service of improving relationships with others. In these therapies, the development of social skills is framed as improving a person’s ability to interact with others, which enhances connection and emotional well-being.
1. Dialectical Behavior Therapy (DBT)
DBT is a form of cognitive-behavioral therapy that explicitly incorporates a relational component. It is focused on reducing suicidal and non-suicidal self-injury, and is most frequently used for people with diagnoses of depression, bipolar disorder, and/or borderline personality disorder (BPD). It involves the development of emotional regulation skills to deal with intense suicidal impulses. Additionally, it features interpersonal effectiveness skills and aims to help build social behaviors that are more effective for meeting one’s needs.
A study of a year-long DBT program for women with the BPD diagnosis compared those who received DBT to those receiving other treatment by “psychotherapy experts” who did not offer DBT. They found that women were half as likely to attempt suicide if they received DBT. They were also less likely to be hospitalized, among other variables. This makes DBT far superior to other therapy for suicide-related issues.
A study in women veterans with the BPD diagnosis found that in addition to improving suicide-related outcomes, DBT also improved depression, hopelessness, and anger expression scores, compared to treatment as usual.
A study adding DBT to medications for “depressed older adults” found that more than twice as many in the DBT group (who also took medication) were “in remission” from depression at the follow-up, when compared to those who took medication without DBT. The addition of DBT appeared to also result in improvements in relationships and adaptive coping skills.
A small study of DBT focused on people who had been classed with “treatment-resistant depression.” The researchers compared the skills training group component with a wait-list control group. Those in the DBT group had large improvements on depression symptoms, in terms of several scales, compared to those on the wait-list.
For more information about DBT in general, here is a link to a very thorough article.
2. Interpersonal Therapy (IPT)
IPT focuses on improving interpersonal functioning by developing strategies for dealing with relational conflicts and how these are communicated. There is also a skills-building element to developing interpersonal communication. This is theorized to relieve depressive symptoms.
IPT is considered a well-supported approach to treatment of depression. One review of the research found it to be about as effective as CBT. That review suggested that about half of the participants in research trials experienced remission from depressive symptoms in both CBT and IPT.
Another review found that IPT was “similar to medication” in effectiveness, and better than CBT in comparisons.
One study featuring impoverished women who had just given birth found that four sessions of group-IPT was superior to treatment-as-usual for preventing a diagnosis of post-partum depression (PPD). Six (33%) of the women in the control group received the diagnosis of PPD, compared to none in the intervention group.
Another review of the research found IPT to be the most effective of all psychotherapies, even more effective than CBT.
3. Psychodynamic Psychotherapy
Current psychodynamic therapy focuses on interpersonal relationships and current life stresses. It borrows from psychodynamic theory in its focus on early-life attachment styles, but has little else in common with psychoanalysis or the psychodynamic therapies depicted in the mass media. It is probably more similar to interpersonal therapy than to Freudian psychoanalysis.
This particular type of therapy has not been studied as frequently as other forms (such as CBT).
One review of the research found that short-term psychodynamic therapy and CBT were equally effective. Another review found that psychodynamic therapy is as effective as other types of psychotherapy.
A study that compared psychodynamic therapy to CBT found that they were about equal in terms of initial effectiveness, although CBT had a slightly larger impact over time. Both interventions resulted in less than a fourth of patients experiencing remission of depression, which the authors hypothesize could be due to the low-income status of the participants. This may indicate that therapy (whether psychodynamic or CBT-based) works better for people without real socioeconomic concerns.
4. Social Skills Training
This intervention is based on the theory that people have poor ways of engaging in social interactions, which makes others avoid them or enter into conflict with them, rather than having mutually satisfying encounters. SST is designed to teach people how to effectively communicate with others in ways that engender these satisfying, positive encounters, which reinforce a sense of connection to others.
This intervention is rarely administered by itself; instead it is more often a component of other interventions, such as CBT or IPT.
A Cochrane review of various behavioral interventions, including social skills training, found that it appears to be as effective as other psychosocial interventions for depression. However, they note that the quality of the evidence was “very weak,” especially when compared to CBT, with its large evidence base.
Another review of the research found social skills training to be as effective as other types of psychotherapy.
C. Holistic Therapies
These therapies focus on improving overall emotional well-being, and are less focused on direct symptom reduction. They tend to view distress as a reaction to a complex life circumstance, and focus on making meaning of that circumstance.
1. Narrative Therapy
Narrative therapy is an intervention designed to address problems by focusing on their context for a person’s life. In theory, it is based on an equitable relationship between therapist and client, although whether this can be achieved given the constraints of the psychiatric system is unclear. In process, the therapy involves deconstructing the stories a person tells themselves about their life, and then reconstructing stories that are more helpful in some way.
Narrative therapy defies easy study, since it is a subjective, postmodern therapy that is difficult to manualize. For this reason, it has rarely, perhaps never, been adequately studied in clinical trials. However, it demonstrates some efficacy in naturalistic studies.
For instance, a study (without a control group for comparison) found that 50% of the participants experienced “clinically significant improvement” in depression scores.
However, without comparison groups or controlled settings, most of the information on the therapy’s effectiveness is based on the subjective opinion of its practitioners and their anecdotal experience.
2. Existential Therapy
Existential therapies use insight from philosophy to make sense of the distress that brings clients in to therapy. These interventions are often conducted in groups. They are based on the theory that existential anxiety underlies all other forms of distress—fears about being alone, the inevitability of death, the meaninglessness of life, and being responsible for one’s own actions. Existential therapists believe that acknowledging and normalizing these fears allows one to find individual purpose and meaning in life. In many existential theories, psychological distress is viewed as the side effect of repressing these basic human fears.
Meaning-based therapies have been described in some foundational works of psychology, such as Viktor Frankl’s Man’s Search for Meaning and Irvin Yalom’s Existential Therapy. Current research has found that meaning-based therapies are effective for instilling a sense of positive meaning in life and, at least in the short term, reducing psychological distress. However, these therapies have rarely been researched in a controlled manner. They have most often been studied in populations with life-threatening illnesses such as cancer and HIV. The same study found that existential therapies worked best when they followed a structured plan and involved frank conversations about death. Therapies that were nondirective and avoided morbid topics were less effective.
3. Positive Psychology
Interventions from positive psychology are intended to focus on a holistic understanding of emotional distress, rather than focusing on symptom reduction. However, the techniques often specifically focus on such topics as coping with stress through humor, thinking of good things, and thinking of funny things.
One study looked at people with depression, anxiety, and adjustment disorder diagnoses. The intervention was “humor training” which aimed to teach people how to cope with stressful situations through humor. One group received the training, and the other did not. The researchers found that the intervention made no difference on any mental health scale, such as depression or anxiety, or even on such topics as humor, seriousness, and bad mood, when compared with the group that received no training. However, those who received the intervention were worse off in some ways: they had more interpersonal difficulties after the “humor training” and reported that the group itself was antagonistic.
Some studies have found that positive psychology interventions, such as the “Fun for Wellness” online program, can result in slight improvements to psychological well-being. It should be noted that in this case, several of the measures did not find an effect.
However, other studies found barely any effect, such as this one, which focused on an online humor-based intervention. Only one of the many techniques showed any effect at all, and even that one was quite small.
IV. Wellness Approaches
Wellness programs focus on improving physical and emotional well-being through diet, exercise, group activities and other social activities. The thought is that depression may lift as people become more fit, find ways to relax, and engage more with others.
The evidence for exercise improving the depressive symptoms and quality of life in youth is recent, but highly promising. In adults, a recent review found that exercise (especially moderate aerobic exercise with a trainer) has a “large and significant antidepressant effect” and that its benefits may have been underestimated due to publication bias.
One review found that exercise was just as good as psychological treatment as well as medications for depression. Another review found that exercise was just as good as sertraline (Zoloft). Additionally, a study found that people with a depression diagnosis who exercised regularly were less likely to die of heart-related illness.
Another study found that, over a longer term, light exercise was slightly better than treatment as usual, but not by much. However, moderate and vigorous exercise were not better than treatment as usual.
Although individual studies appear highly favorable toward exercise, reviews that analyzed all the research have been slightly more equivocal. For instance, a Cochrane review found that numerous methodological flaws permeate the research on exercise (e.g. lack of blinding, not using intention-to-treat analysis). When they included only very well-conducted studies, the effectiveness of exercise dropped considerably. Nonetheless, exercise was still just as good as cognitive therapy, in their analysis.
Further research needs to verify these findings with other control groups and compare findings with other psychological interventions. However, given the lack of adverse effects and the known benefits of exercise, it is an extremely promising intervention.
A subset of the research on exercise. The research on yoga as an intervention for depression is limited. Very few controlled studies have been conducted. However, reviews of those studies that do exist have found that yoga appears to be effective at reducing depression scores. One recent review found that yoga was no different in effectiveness than exercise or antidepressant treatment.
One study in women found that a mindfulness-based yoga intervention was about as good as walking regularly, in terms of reducing scores on depression measures. That study also found that rumination (repeatedly thinking about an unchangeable past or worrying about the future) was reduced far more by the yoga intervention than by walking.
A study on exercise that included yoga found that both yoga and more intense exercise were “at least as effective as treatment as usual by a physician.”
Reviews have also noted that the studies on yoga have unclear, potentially biased methodologies. As more rigorous studies are conducted, we may see the effectiveness of this intervention diminish.
According to the research literature, a healthy diet appears to consist of mostly vegetables, fruit, fish, and nuts, with very few processed foods, and very few high-fat and high-sugar content foods. Diet interventions for depression have in research have taken several forms, including reduced caloric intake, reduced fat intake, and increased intake of healthy foods.
One review of the research literature found that only slightly less than half (47%) of the studies on diet for depression found a positive effect. This calls into question the effectiveness of this intervention.
However, a recent large-scale review of the research focused on what factors were shared amongst those studies that did find an effect.
They found that the interventions had a positive effect on reducing depressive symptoms, but only for women. Men were likely to either not improve, or actually have worsening depressive symptoms. This could be due to the cultural expectations around women’s body image and dieting.
The interventions were also only successful if they were led by a dietician/nutritionist. If they were carried out by other treatment professionals, they appeared to have no effect on depressive symptoms.
The most successful interventions were those targeting reduced fat intake and reduced caloric intake. For some reason, the interventions that focused on improved overall nutrition were sometimes effective, sometimes not—averaging out to no real effect.
Most of the trials on diet have used a “subthreshold” sample—people who do not have the diagnosis of depression. They analyze the effect of diet on the experiences measured by depression scales, but it’s unclear how this might generalize to people who have really intense experiences that meet the criteria for a diagnosis.
In these studies, improving diet appeared to have very little to no effect on anxiety.
One study that examined the Mediterranean diet in a sample who actually had the diagnosis of depression did find that it significantly improved symptoms. In this small study, with a personal dietician leading an individualized diet, it appeared very positive. People who had the diet were far more likely to experience full remission of their symptoms, when compared to a “befriending” control group.
In sum, diet is probably a good alternative to other treatments for depression, but only if you’re a woman who can have an individualized plan crafted by a personal dietician/nutritionist.
4. Fish Oil
Fish oil contains omega-3 fatty acids, including EPA and DHA. They are also known as poly-unsaturated fatty acids (PUFA), which are theorized to support emotional well-being on a biological level. As with antidepressants, controlled studies have found a slight benefit for omega-3 supplementation when compared with placebo; however, this effect is unlikely to be clinically significant. When tested in people with a PTSD diagnosis, the study had to be stopped early: omega-3 supplementation resulted in early drop-outs due to adverse events, as well as worsening avoidance and other problems.
Having a pet can foster a sense of connection, and of responsibility for another’s well-being. It can enforce a regular schedule, encouraging people to get out of bed. It can also require engaging in activities (such as dog walking) which provide opportunities for physical exercise and meeting others. Physical touch with animals may also have an effect on well-being.
Although research on this topic is slim, studies have found that animal-assisted therapies result in reduced depressive symptoms on depression rating scales. Another study found that having a dog is associated with reduced odds of depression after a diagnosis of a life-threatening illness.
Studies have found similar results for having cats as well. In fact, one study found that cat owners had even lower scores on a depression scale than dog owners, but this was one small study and people were not randomly assigned an animal. Personal preference is most likely a factor.
Importantly, however, depression and anxiety may worsen if the animal’s health suffers.
Volunteering also requires keeping to a schedule as well as engaging in activities that foster both human connection and a sense of purpose and meaning. Although the research on this as a psychological intervention is minimal-to-nonexistent, surveys and anecdotes support the idea that helping others through volunteer work improves emotional well-being.
Research compiled by Peter Simons