Depression, Diabetes, and Obesity: Case Study and Treatment

Introduction and Patient Background

This is a case study of a 58-year-old male who worked at a supermarket and is now retired. He has a supportive wife who works full time and children who are all independent. He has a history of smoking but quit ten years ago, and he drinks alcohol twice a week. He is obese and has been a known case of type 2 diabetes for one year. He has gained 8 kg over the past four months and his blood glucose levels are uncontrolled. He denies feeling sad but no longer enjoys activities he once did, feels tired and lethargic after any exertion, and his sleep pattern is disturbed. His drug history reveals that he is taking glyburide and multivitamins. He has scored 14 on his PHQ-9, which indicates moderate depression. The patient has been diagnosed with depressive disorder not otherwise specified (DSM-IV 311).

The patient has type 2 diabetes, also known as non-insulin-dependent diabetes. It is a metabolic disorder in which the beta cells of the pancreas do not produce enough insulin, or there is resistance to the action of insulin on the body's cells (Kumar et al., 2010). It affects 8.3% of the U.S. population (CDC, 2011). He has not been taking his diabetes medications regularly, which increases his risk of developing complications. He is also obese, a condition caused by various factors including environmental, genetic, cultural, dietary, socioeconomic, endocrine, and lifestyle influences. In this patient's case, obesity is most likely attributable to his sedentary lifestyle, lack of exercise, and depression. Obesity is prevalent among 35.7% of the U.S. population, and one-fourth of obese patients are likely to develop depression (CDC, 2011). Obesity can also lead to certain cancers, coronary heart disease, and premature death.

The social and lifestyle determinants responsible for his condition most likely include early retirement due to comorbid illnesses, increased free time, alcohol consumption, a past history of smoking, a full-time working wife, and the burden of managing a chronic illness.

Diagnosis

According to the DSM-IV, this patient has been diagnosed with Depressive Disorder Not Otherwise Specified because his presentation does not meet the full criteria for Major Depressive Disorder, Dysthymic Disorder, Adjustment Disorder with Depressed Mood, or Adjustment Disorder with Mixed Anxiety and Depressed Mood. This classification includes premenstrual dysphoric disorder, minor depressive disorder (in which two to five symptoms of major depressive disorder are present for more than two weeks), recurrent brief depressive disorder, depressive disorder due to an underlying medical condition or substance abuse, and post-psychotic depressive disorder of schizophrenia (American Psychiatric Association, 2000).

To be classified as major depressive disorder, a patient must have experienced at least one episode in which five or more of the following symptoms were present for more than two weeks: feelings of emptiness or sadness, decreased pleasure in previously enjoyed activities, significant weight loss or gain, disturbed sleep (insomnia or hypersomnia), fatigue, suicidal thoughts, feelings of guilt without valid cause, and slowed neurological function or inability to concentrate (American Psychiatric Association, 2000). This patient denies feeling sad, reports no guilt, and has no suicidal ideation, but is experiencing all other listed symptoms of depression.

Depression occurs in approximately one in ten adults in the United States. It is influenced by biological factors—studies show a high incidence among first-degree relatives even when they have not been raised together—as well as environmental factors. Lack of family support, stress, financial difficulties, and occupational problems are situational factors that can worsen a depressive disorder (NANDA Nursing, 2012).

Treatment of type 2 diabetes requires tight glycemic control and lifestyle modifications including regular exercise and a diet low in carbohydrates and high in protein. Several pharmacologic drug classes are available to help maintain blood glucose levels. Sulfonylureas stimulate the release of insulin from the pancreatic beta cells. Meglitinides also stimulate insulin release but are shorter-acting than sulfonylureas. Biguanides reduce hepatic glucose production and increase peripheral glucose utilization. Alpha-glucosidase inhibitors delay glucose absorption and prevent post-meal glucose spikes. Glitazones increase insulin sensitivity. Incretin mimetic agents reduce glucagon secretion and stimulate insulin release. If all oral therapy fails, insulin may be added to the regimen. The patient should also aim to reduce his weight through regular exercise, reduced alcohol intake, and behavioral changes such as joining support groups. Diet modifications, and in some cases pharmacologic or surgical weight-loss interventions, can further assist with weight reduction (NANDA Nursing, 2012).

Treatment Options

Depression is effectively treated with pharmacologic therapy combined with cognitive behavioral and interpersonal therapy. Selective serotonin reuptake inhibitors (SSRIs)—including citalopram, escitalopram, fluoxetine, fluvoxamine, paroxetine, and sertraline—are the first-line drug treatment for depression. They act by inhibiting the reuptake of serotonin (5-HT) and stimulating 5-HT-1 receptors, producing antidepressant and anxiolytic effects. SSRIs have a favorable safety profile, are easy to administer, and do not require dose adjustment. Potential side effects include nausea, anxiety, insomnia, and sexual dysfunction.

Serotonin modulators such as trazodone, nefazodone, and mirtazapine block 5-HT-2 receptors and inhibit reuptake of serotonin and norepinephrine. Nefazodone does not cause sexual dysfunction and promotes restful sleep without suppressing REM sleep, though it carries a risk of hepatotoxicity. Mirtazapine blocks 5-HT-2 and 5-HT-3 receptors and enhances serotonergic function without causing nausea or sexual dysfunction, but it does cause weight gain and sedation. Selective norepinephrine reuptake inhibitors (SNRIs) such as duloxetine and venlafaxine share a mechanism with SSRIs and carry similar toxicity profiles; they may cause loss of appetite, dizziness, fatigue, weight loss, nausea, sexual dysfunction, urinary retention, and elevated blood pressure. Norepinephrine-dopamine reuptake inhibitors such as bupropion do not act on the serotonin system but instead influence catecholaminergic, noradrenergic, and dopaminergic function; they can cause agitation and hypertension. Monoamine oxidase inhibitors (MAOIs) increase the availability of norepinephrine, dopamine, and other phenylethylamines and are reserved as a last resort when depression is refractory to all other antidepressants and to electroconvulsive therapy. They must never be combined with a tyramine-rich diet or sympathomimetic drugs. Heterocyclic antidepressants increase availability of serotonin and norepinephrine; they are effective but rarely used due to overdose toxicity and a greater adverse-effect burden than newer agents (Mycek, Harvey, & Champe, 2010).

Several non-pharmacologic treatments exist for depressive disorder, of which psychotherapy is the most thoroughly studied. Psychotherapy alone is beneficial for mild to moderate depression, and is frequently combined with pharmacotherapy for severe depressive disorder. Among all psychotherapeutic approaches, Cognitive Behavioral Therapy (CBT) and Interpersonal Therapy (IPT) have yielded the most consistently positive results (Gelenburg et al., 2010).

CBT combines cognitive therapy—which focuses on how thoughts and beliefs affect mood and behavior—with behavioral therapy, helping patients change maladaptive thought patterns and eliminate unhealthy behavioral habits. The therapist works with the patient to distinguish harmful behaviors from healthy ones and to develop strategies for changing negative patterns into positive ones. The role of CBT in treating depressive disorder alongside type 2 diabetes is significant and is associated with improved glycemic control. One study found that 85% of patients who received CBT achieved remission of moderate depressive disorder after ten weeks of therapy, and approximately 70% remained symptom-free at the six-month follow-up (Williams, Clouse, & Lustman, 2006).

Interpersonal Therapy focuses on the interpersonal context of mood disorders and on building interpersonal skills. It is grounded in the behavioral-psychosocial model, which holds that mood disorders are related to interpersonal processes and should be treated accordingly. IPT aims to change a patient's interpersonal behavior by helping the individual adapt to current roles and relational situations (Wood & Wood, 2008).

Electroconvulsive Therapy (ECT) is a somatic treatment of choice for patients with severe major depressive disorder that has not responded to psychotherapy, pharmacotherapy, or a combination of both. It is of particular benefit when there is significant functional impairment, when multiple treatment trials have failed, or when the patient presents with psychotic or catatonic features, or requires urgent intervention—for example, in the case of active suicidal ideation (Gelenburg et al., 2010). The precise mechanism of action of ECT is unknown; the therapy involves electrically induced seizures in anesthetized patients.

Psychodynamic therapy and problem-solving therapy are less commonly used approaches. Psychodynamic therapy addresses the patient's subconscious processes and how they shape behavior, with the goal of increasing awareness of how past experiences and unresolved conflicts influence current functioning. It may be especially useful in patients with depression associated with alcohol or substance use (Wood & Wood, 2008). Problem-solving therapy is a brief psychological intervention comprising approximately seven sessions, during which the clinician helps the patient identify life problems, examine each individually, and apply a structured approach to resolving them (Wood & Wood, 2008).

Light therapy (phototherapy) is used primarily for Seasonal Affective Disorder, a form of depression that recurs seasonally, typically in fall or winter. The patient sits near a light box that emits artificial light, which stimulates neurotransmitter activity in the brain and improves depressive symptoms. Light therapy may also have some benefit for other depressive disorders, sleep disturbances, and conditions linked to abnormal neural transmission (Wood & Wood, 2008).

Some studies regard hypnotherapy as an effective adjunct for treating depression associated with comorbid conditions. Although results have been promising when hypnotherapy was combined with CBT, the evidence base is insufficient to support a formal recommendation at this time (Gelenburg et al., 2010).

Several factors affect the frequency and type of psychotherapy sessions selected, including: severity of the depressive disorder, comorbid conditions, patient cooperation, availability of social support, and the frequency of visits needed to build and maintain the therapeutic relationship, ensure treatment compliance, monitor progress, address complications, and assess suicide risk (Gelenburg et al., 2010).