Depression Treatment: Multiple Pathways of Influence

by Donald Gorassini, howinfluenceworks.com

This blog reviews therapeutic treatments for clinical depression, thus focusing on a beneficial form of influence where the recipient’s best interests take priority. The problem of depression is a pressing and widespread one. Its treatment falls within the broad category of social influence because human beings have intentionally developed and applied these interventions to change the condition of other human beings.

Depression treatment illustrates the compassion, diversity, and strength of human influence. Significant shifts for the better in symptoms may arise from several methods of the exceptionally diverse array that have been developed.

I will describe the many methods used to treat depression and review literature on their effectiveness when applied individually and in tandem. This provides useful information on influencing depression. For a site devoted to understanding social influence, it provides something more: it offers a model for a possible approach to altering the mind and behavior generally.

Clinical Depression

When I refer to depression here, I mean major depressive disorder (MDD), a clinical condition. Because symptoms can be severe, patients usually consult a health professional. If MDD is suspected or used to exclude other concerns, criteria in a diagnostic manual guide the assessment of whether the disorder exists. If confirmed, a treatment plan is developed that includes a procedure designed to help the recipient. Its implementation is thus social influence.

Major Depressive Disorder

Major depressive disorder involves depressed mood and/or a marked loss of interest or pleasure, together with other symptoms that cause significant distress or impairment. In outline, the criteria for MDD as stipulated in a widely used diagnostic manual, the DSM-5-TR¹, are: (1) At least five of nine listed changes—which must include depressed mood or loss of interest or pleasure—must be present.² (2) The symptoms reflect clinically significant distress or impairment. (3) The symptoms must have persisted for at least two weeks. (4) The symptoms cannot be better explained by another medical condition (example: thyroid disorder), ingestion of a substance, or manic/hypomanic disorder.

Frequency of Occurrence

Among adult Americans, roughly 8.3% experienced a major depressive episode during the preceding year.³ The corresponding Canadian estimate is about 3.9%.⁴ Women experience major depression at considerably higher rates than men. This represents many individuals, substantial distress, and a major effect on health systems in both nations.

A second measure involves lifetime prevalence, meaning at least one episode of MDD during a person’s life. Because the estimate spans an entire lifespan, the figure is naturally higher than one-year prevalence. A different U.S. survey found a lifetime prevalence of DSM-5 major depressive disorder of 20.6%.⁵ Canada shows 9.9%.⁶ Over the world, depression rates differ considerably among nations.⁷ Surveys and compilations emphasizing lifetime prevalence across various nations indicate a spread from roughly 1% to nearly 20%.⁸ The differences suggest the operation of social and cultural influences, although differences in measurement and reporting also contribute.⁹

Influence Through Information

As human beings, we learn through instruction and experience. We might be told that water is wet, or we might walk in the rain. Both methods provide information by indicating directly that water is wet. They work well together. Instruction suggests a possibility, making the point quickly and with the precision of language. Experience teaches us if the possibility is real. Psychotherapies draw on one or both of these modes to deliver a lesson meant to ease depression.

Psychotherapy

Psychotherapy is frequently applied as a standalone approach for depression and may be combined with therapeutic drugs. It relies on social interaction between therapist and client, encompassing dialogue, training, or both. Dialogue serves as a channel for instruction through conversation, advice, direction, suggestion, questioning, evaluation, and feedback. Training generates experiences that support learning, and can include instruction, encouragement, assignments, practice, role-playing, exposure to consequences, and progress charting. These two methods are complementary and integrate smoothly.

The most extensively studied psychotherapy for depression is cognitive-behavioral therapy (CBT). In regard to the cognitive component, it is assumed that depression is maintained by negative views of self (“I can’t do anything; “I’m no good.”), the world (“It’s a cruel world.”), and the future (“I’m gonna die alone”.). The therapeutic strategy applies talk and other techniques (e.g, diaries) designed to modify these patterns of thinking, with the expectation that this will contribute to improvement in depressive symptoms.¹⁰

For example, a woman in her fifties with depression felt she had been a bad mother. The therapist pointed out that her four children were all successful and happy in their lives. Therapist: “You couldn’t have been all that bad.” Client: “Well, I guess I had my moments.”

The behavioral component consists of inducing behavior or altering the person’s environment in some way. The therapist might ask the depressed woman to chat with her children more often and later discuss the results within a therapy session. This would comprise a change in behavior and environment. The follow-up review would be a further opportunity for targeting cognitions.

Through therapy and the use of several established methods, enduring shifts in thinking, surroundings, and actions are expected to emerge, which should ease the mood symptoms they are thought to produce.

A typical course of Beck’s CBT consists of approximately 12 to 16 one-hour sessions conducted once a week, although treatment length varies according to the patient and the form of CBT used. A goal is ultimately to provide people the skills for treating themselves. The patient is encouraged to return when needed. So, the therapy has a clear rationale, straightforward tactics, and is applied reasonably quickly.

In a large recent analysis of psychotherapy effectiveness involving all the major psychotherapies, conducted over many years, and involving tens of thousands of participants, CBT was the most frequently examined, in 52% of cases. CBT led to improvements in symptoms relative to no-treatment participants. Time and again over its 50 years of implementation, CBT has been found effective. Alongside this finding is the equally important result that other psychotherapies, using different approaches, are about equally effective.¹¹

Beyond cognitive and behavioral approaches, several psychotherapies exist: interpersonal psychotherapy aims to enhance relationships and ease life transitions; psychodynamic therapy seeks to adjust maladaptive emotional patterns; problem-solving therapy targets coping with practical issues; supportive therapy offers reassurance and adaptive connections; and humanistic therapy fosters acceptance and self-understanding.¹²

Although these methods carry different names, use varied techniques, and arise from distinct traditions, two shared features make them more alike than their labels imply. First, they necessarily share common practices, such as a therapist relationship, problem-solving, self-reflection, and awareness of being helped. Second, key techniques vary more in degree than in type. For example, insight therapies (like psychodynamic and humanistic approaches) and cognitive therapies both seek changes in the person’s habitual patterns of thinking, feeling, and responding, although they conceptualize those patterns differently.

Comparative research has found surprisingly little difference in the average efficacy of established psychotherapies for depression. A network meta-analysis of 331 randomized trials involving more than 34,000 patients found that the major psychotherapies examined—including cognitive behavioral therapy, behavioral activation, interpersonal psychotherapy and psychodynamic therapy—were generally more effective than usual care or waiting-list controls, while the psychotherapies generally did not differ significantly from one another.¹³ More recently, a meta-analysis specifically designed to test equivalence found that standardized psychodynamic therapy and CBT were statistically equivalent immediately after treatment, although the available evidence was insufficient to establish equivalence at follow-up.¹⁴

The many different ways of interacting with a client that these therapies represent indicate that there are many avenues into the mind in an interpersonal setting. Each form of influence ultimately produces changes in brain processes, psychological experience, behavior, or some combination of these that can reduce depressive symptoms.

Computerized Psychotherapy

Computer-assisted psychotherapy for depression, which commonly applies CBT techniques, emerged during the 1980s.¹⁵ Originally provided through desktop computers, it grew more accessible online—known as iCBT—during the 1990s and 2000s.¹⁶ The broad application of CBT in these programs reflects the tangible, well-defined, and therefore readily adaptable quality of CBT methods.¹⁷

Computer methods in therapy have evolved through three phases: 1) therapist-designed tools, such as self-help apps for independent use; 2) therapist-supervised methods, where guided therapy apps operate under therapist oversight, now mainly delivered on the internet; and 3) AI-assisted or AI-generated approaches, in which AI systems can generate individualized therapeutic interactions, sometimes without direct human supervision.

Large research reviews indicate that both therapist-designed and therapist-supervised computer approaches to depression therapy are more effective than control methods, with therapist-supervised approaches showing greater effectiveness.¹⁸ Differences in persistence were noted at one-year follow-up.¹⁹

An expanding set of studies on AI-assisted and AI-generated methods indicates potential. This body of work is considerably newer and less developed than research on conventional psychotherapy and iCBT. Current AI investigations suggest modest benefits, although the evidence remains heterogeneous.²⁰ Because AI methods have varied so widely thus far, it is still uncertain which might show reliable or even robust results.²¹

Influence Through Changes in Behavior/Environment

In behavioral therapy, nowadays referred to as behavioral activation therapy, the focus, as noted, is on changing behavior and environment, thus comprising experiential learning. The underlying idea is that withdrawal and inactivity drive depressive mood, leading to fewer rewarding experiences; boosting activity and reward opportunities may thus restore pleasure in living.²²^,²³

CBT already includes this behavioral element. It is notable that a behavioral component alone has improved depressive symptoms relative to controls and matches CBT in effectiveness.²⁴

CBT and behavioral therapy both aim to alleviate mood symptoms but use different approaches. CBT focuses on changing cognition, environment, and behavior, while behavioral therapy directly targets environment and behavior. Despite their different pathways, both methods ultimately lead to similar relief from mood symptoms. This result is important given that behavioral activation therapy costs less to deliver than CBT.²⁵

Influence Through Direct Biological Intervention

A biological therapy uses a delivery method that changes the body directly, including pills, injections, surgery, mechanical manipulation, magnetic fields, electrical current, or brain implants.

The influence is social in origin and application, even when its immediate mechanism is biological. People discover, design, prescribe, administer, and receive these interventions as part of an organized human relationship. The fact that a treatment at some point changes neural activity does not make its origin or use any less a product of human influence. Indeed, psychotherapy changes neural activity through the sensory systems of the body.

Antidepressant Medication

The administration of drugs to treat a disorder is termed pharmacotherapy. Antidepressant medication, usually introduced chemically in pill form, is the most frequent approach for treating depression. Selective serotonin reuptake inhibitors (SSRIs) represent a common class within this group. Other medications include selective norepinephrine reuptake inhibitors, atypical antidepressants, tricyclic antidepressants, and MAO inhibitors; these drugs are believed to modify neural activity in the brain.

Large-scale studies provide strong evidence that these medications reduce symptom severity. Two very similar conditions were compared, differing in one key way: participants received pills the same way, but only one group’s pills contained the treatment chemical. Each condition is otherwise comprised of many elements—physical setting, pill appearance and taste, prescribed schedule of the pill, belief in treatment, interacting with study personnel, group makeup, and more. Because the active ingredient is the principal intended difference between the two conditions, the additional benefit is attributed to the drug’s pharmacological action, subject to the usual limitations of placebo-controlled trials. Thus, improvement in the placebo condition should not be equated with the placebo effect itself. The condition includes expectancy, attention, contact with clinicians, assessment, natural symptom fluctuation, regression to the mean, and other influences.

Antidepressant effects exceed those in two baseline types: placebo conditions and groups not yet given the treatment drug.²⁶^,²⁷

Electro-Convulsive Therapy

Electro-convulsive therapy (ECT) applies a controlled electrical stimulus through the scalp of an anesthetized patient to induce a therapeutic seizure. Canadian guidelines have historically placed ECT among the most effective neurostimulation treatments and rTMS (see below) as an important less invasive alternative.²⁸ It is particularly important for severe depression, treatment-resistant depression, depression with psychotic features, severe suicidality, and situations requiring rapid improvement.

Transcranial Magnetic Stimulation

Transcranial magnetic stimulation is referred to as rTMS (“r” for repetitive) because the treatment delivers a train of repeated magnetic pulses rather than just a single isolated trial. The source is a small wand-like device that is held just outside the skull. Unlike ECT, rTMS does not require general anesthesia and is considerably less invasive. A meta-analysis of 65 sham-controlled randomized trials involving nearly 3,000 patients found that rTMS reduced depressive symptoms and increased the likelihood of remission more than sham treatment.²⁹ Very recent research continues to find significant effects of modern rTMS protocols over sham treatment.³⁰

The medication, ECT, and rTMS studies demonstrate marked differences when compared to one another in method. This ranges from chemicals introduced into the digestive system (pill) or bloodstream (injection), to diffuse neural stimulation of the brain by electrical current to the scalp, to somewhat more focused neural stimulation to the brain by magnetic field applied just outside the skull. The brain is affected in all instances. The routes are radically different; the intended outcome is the same: reduction of depressive symptoms.

Deep Brain Stimulation (DBS)

In DBS, electrodes are surgically implanted into the brain. A mild electrical current is run through the electrodes on a periodic schedule from a small computer installed in the chest. This should be seen as an experimental biological approach with potential but whose efficacy for depression has not yet been established to the same degree as ECT, rTMS, antidepressants, or psychotherapy. With respect to potential, it gives with one hand and takes away with the other. It could target the neural tissues of the brain very accurately but it is invasive and very expensive.

Influence Through Expectations/Context

It is important to note that substantial placebo effects often emerge in these studies. A substantial proportion of participants in placebo conditions improve, although the proportion varies considerably among studies. The additional benefit of medication over placebo is often considerably smaller than the improvement observed in the placebo condition.³¹ As emphasized above, the improvement rate in a placebo group does not stem solely from believing one is being treated and possible expectations that improvement beckons; these beliefs combine with an entire context to shape depressive symptoms, reflecting a distinct social influence.

Combining Pathways

Comparative research has found surprisingly little difference between psychotherapy and antidepressant medication in their average ability to reduce acute depressive symptoms. A 2013 review of 67 randomized trials found no significant overall difference between psychotherapy and medication.³² A much larger 2020 analysis reached essentially the same conclusion: the two approaches produced very similar response rates. Combining them, however, increased the likelihood of both response and remission.³³ These large reviews of research suggest that psychological and biological interventions can each exert substantial effects on depression, while their combination may produce additional benefits.

The combined result of research into depression treatment broadens the lesson drawn separately from psychotherapeutic research and biological therapy research. In each case there was a variety of ways into the brain and mind to produce a result on mood. In comparing the two approaches to each other, and with placebo conditions, we see an even wider spectrum of methods, evincing an even wider array of pathways into brain and mind. Moreover, while many of the treatments have broadly similar average effects, combining CBT and medication can produce additional benefit.

The observation that two therapeutic pathways can yield a stronger effect than either alone is significant. This supports testing multiple routes of influence and, through their combination, uncovering enhanced outcomes. Beyond practical treatment benefits, identifying combined effects offers insight into why a specific pairing might excel. One possibility—still speculative—is that medication may reduce painful affect enough to make engagement with CBT easier.

Conclusions

In this blog on depression treatment, we see that human beings have discovered multiple routes by which one person’s actions, knowledge, and technology can change another person’s brain, behavior, and subjective experience. Conversation can work. Behavioral change can work. Computerized interaction can work. Drugs can work. Brain stimulation can work. Expectation/context can contribute. Combinations can work. It is a rich and powerful example of human influence.

This multifaceted approach, having demonstrated that depression can be influenced through multiple pathways, might be tried elsewhere. Each of the methods used to treat depression, and their various combinations, could potentially be adapted to alter any number of outcomes of significance. Future contributions could address questions of relevance both to depression treatment per se and to other social influence realms.

Study Questions

Where exactly is the boundary between psychological and biological influence?
Could future technologies directly modify beliefs, memories, motivation or other psychological states?
Could the same multiple pathways used beneficially in depression treatment be used for harmful social control?