Literature on the overall efficacy of psychological interventions in reducing clinical depression in patients with cancer is limited. There are few high-quality randomized controlled trials (RCTs) of interventions in patients with cancer with clinical depression specified as an outcome and measured using validated tools [5, 42]. Additionally, there is a lack of clarity in defining “psychological interventions” in the cancer literature [43]. In a systematic review of RCTs for depression in adult patients with cancer, Walker et al. found only eight published manuscripts (describing seven trials) that met inclusion criteria for the analysis. Only one was a trial of psychotherapy, which found that behavioral activation and problem solving were both effective in treating depression in patients with breast cancer [5].

While psychotherapeutic and pharmacologic interventions have been shown to be efficacious for depression in some studies, the effectiveness and potential harms of different treatment approaches for depression in cancer patients are largely unknown, underscoring the need for more comparative effectiveness studies [5, 37]. A common call is for improved quality of study design and reporting, clear definition of clinically defined and measured end points, and unbiased reporting of results.

Research supporting various psychotherapeutic interventions in specific groups of cancer patients has examined a variety of outcomes. In a systematic review of interventions for patients with gastrointestinal cancers, interventions including various types of psychotherapy as well as exercise and pharmacologic interventions were generally found to be effective in reducing physical and psychosocial symptoms and improving quality of life [44]. In patients with colorectal cancers, various interventions were found to reduce length of hospital stay, days to stoma proficiency, symptoms of anxiety and depression, and quality of life [45]. In patients with prostate cancer, psychotherapeutic interventions have been found to improve the quality-of-life outcomes and increases in knowledge, but the clinical significance of these benefits is unclear [46].

The overall aim of psychotherapy in the oncology setting is to help patients improve coping strategies and promote adjustment to cancer diagnosis and treatment [37]. Other goals of therapy include reduction of distress, improvement of problem-solving skills, assistance in finding other sources of support, and reshaping negative or harmful thoughts. Additional benefits can be drawn from emotional support from the provider. Common therapies used with patients with cancer include supportive-expressive therapy, various types of cognitive behavioral therapy (CBT; including cognitive behavioral stress management and problem-solving therapy), and psychoeducational interventions.

Supportive, cognitive behavioral, and family or couples therapy are well supported by RCTs, reviews, and meta-analyses to be effective in reducing distress and improving quality of life in patients with cancer [4, 6]. In a meta-analysis of the efficacy of interventions for depressive symptoms in adults with cancer, Hart et al. evaluated ten RCTs with 1362 participants with mixed cancer types [4]. The authors found that five psychotherapeutic and four pharmacologic interventions were superior to control conditions for reducing depressive symptoms in adults with cancer (effect size d = .42). Interventions that were selected for elevated distress had larger effect sizes than those that did not select for elevated distress [4]. A meta-analysis of psychotherapeutic interventions targeting cognitive dysfunction in patients with various cancers showed no evidence of effect for reduced cognitive complaints but good support for improved quality of life [47]. Similarly, a systematic review of information provision and needs in patients with various cancers found that patients who were most satisfied had fulfilled information needs and experienced fewer information barriers, reported better health-related quality of life, and had less anxiety and depression; however, the authors found that reports of successful psychoeducational interventions aimed at improving information provision for patients are lacking [48].

One of the most effective behavioral interventions for patients with cancer may be promotion of physical activity. Exercise has been associated with improvements in physical and psychological function and has the added benefit of improving body image and health-related quality of life in patients with cancer [49, 50]. Across cancer types, exercise may have beneficial effects over time on fatigue and physical and social functioning. The authors found that positive effects of exercise interventions are more pronounced with moderate- or vigorous-intensity vs. mild-intensity exercise programs but concluded that further research is needed to determine how best to sustain positive effects of exercise over time and the essential attributes of exercise (mode, intensity, frequency, duration, timing) according to cancer type and treatment [51].

It may be particularly important to treat depression in the palliative care setting. There is little evidence supporting specific therapies in palliative care settings, but medications, CBT, problem-solving therapy, mindfulness techniques, and supportive therapies may all be helpful [20]. There is also growing evidence that quality palliative care itself may have significant psychosocial benefits. Early palliative care in patients with metastatic non-small cell lung cancer resulted in improved quality of life and less depression than in controls who received standard oncologic care alone. Patients in the early palliative care group had less aggressive end-of-life care but had longer survival [52].

Patients and caregivers may experience a decline in emotional well-being, including an increase in depression, when barriers to treatment are not addressed and access to treatment or treatment engagement is impeded. Oncology social workers are often part of the multidisciplinary oncology team and can help manage the emotional, social, and concrete needs of patients, families, and caregivers. Social workers can provide navigational support and advocacy within complex medical systems, identify psychosocial or situational issues that may impair a patients’ ability to engage in treatment, and help to coordinate referrals to other supportive services, such as psychiatry, psychology, chaplaincy, palliative care, and support groups. They may also provide direct counseling and emotional support to patients and family members on issues including grief and loss, communication with family/couples and medical providers, parenting and family concerns, substance use and co-occurring disorders, medical-legal documents, and practical issues such as transportation and financial assistance.

With social workers often being co-located within an oncology treatment setting, they can routinely connect with patients in person or by phone to provide information or support, such as following significant medical appointments where they may have learned of disease progression or a recurrence. In this capacity, they are in a good position to initially screen and identify patients who are in high distress and engage them in treatment [53].

There are 4.6 million Americans who care for someone with cancer at home [54]. A diagnosis of cancer can be overwhelming for both patients and family members, resulting in many lifestyle and role changes. While assessing the impact of cancer and treatment on the family, it is helpful to understand the patient’s and family’s baseline strengths and difficulties, as preexisting psychosocial and mental health issues may be exacerbated by a cancer diagnosis.

Psychosocial care that supports patients and family members in establishing routine pleasant activities and rituals, re-establishing roles, and creating family time for communication and other activities can ease the burden of cancer and result in improved patient and family emotional and mental health [55]. Studies with non-cancer patients suggest that the presence of effective family caregivers can increase treatment adherence and improve overall care. For example, caregivers increase the probability of adherence to medication regimens, exercise protocols, and dietary recommendations, thus potentially diminishing the frequency and duration of hospitalizations. It is important to recognize, however, that a caregiver’s negative emotional state, cognitive and physical impairments (including fatigue), and low literacy can impede their ability to accurately manage patients’ medications [56].

A recent review of meta-analyses indicates that stress in caregivers can lead to psychological changes, sleep disturbances, and changes in physical health, immune function, and financial well-being. The authors note that when the patient and caregiver dyad is collectively treated, well-being of both parties is improved [57]. Research-tested interventions delivered to caregivers of patients with cancer have demonstrated reductions in many negative effects and improvements in caregivers’ coping skills, knowledge, and quality of life. These interventions may also reduce patients’ symptoms, lower mortality, and enhance patients’ physical and mental health [57]. Most of the published studies on interventions for caregivers are psychoeducational in nature, providing information on helping to manage the patient’s physical and emotional care. Other interventions focus on skills training (e.g., developing coping skills or training on couples’ communication strategies) or therapeutic counseling. Although these studies tended to have small to moderate effect sizes, they consistently demonstrated improvements in both patient and caregiver physical and mental health outcomes [57]. Depressed mood in spouses of patients with breast cancer has been shown to have a negative impact on the patient’s own functioning and well-being. Factors identified as risks for elevated depression in spouses of women with breast cancer include older age, less education, more recent marriage, elevated fears regarding their wife’s well-being, worry about their job performance, uncertainty about the future, and poorer marital adjustment [58]. It is critical to attend to modifiable risk factors in spouses and caregivers of all cancer patients, as it is likely that earlier intervention and support will benefit the family member and the patient themselves.