Depression: Essential Study Facts For Medical Students

Depression is common. Its a condition seen by most doctors on a regular basis either as a primary concern or often as part of an overall picture. It is therefore very likely to be a topic that is assessed in medical student exams.

What are the key facts that medical students should understand about depression? Well these would include the following:

• that depression is a common mental health condition;
• the key diagnostic condition in DSM5 is Major Depressive Disorder in which 9 possible symptoms are described: depressed mood, anhedonia, weight changes, sleep changes, psychomotor disturbances, fatigue, feelings of worthlessness or inappropriate guilt, diminished thinking abilities, and recurrent thoughts of death or suicide;
• treatment in a biopsychosocial framework is important with the main treatments being: psychoeducation and lifestyle changes, antidepressants and psychological therapies
• patients can utilize online treatments effectively; and
• the impact on carers should be remembered.

Read on further for more information about how we diagnose and help treat depression.

Major Depression. The Technical Name for Depression

Major depressive disorder (MDD) is the ‘technical term’ to describe what is commonly referred to as ‘depression’. It is more than just feeling down or sad.  MDD is not a sign of weakness. It is not possible for the person who is suffering from MDD to ‘pull themselves out of it’, even if this may be the advice from well-intentioned friends and family.

MDD affect feelings, thoughts, behaviour, and day-to-day functioning. It ranges in severity from mild (e.g. 1-2 symptoms), to moderate (three symptoms), to severe (four or five symptoms, with motor agitation).
Major depressive disorder is common. It’s likely either yourself or someone you know has experienced it or been affected by it in some way.

There are clear diagnostic criteria for diagnosing MDD in the DSM 5 (the diagnostic manual mental health professionals use). Five or more of the following have been present during the same 2 week period, and represent a change from usual functioning. At least one of the symptoms is 1.) Depressed mood or 2.)anhedonia ( i.e. loss of interest/pleasure).

DSM 5 Criteria for Major Depression. The individual must be experiencing five or more symptoms during the same 2-week period and at least one of the symptoms should be either (1) depressed mood or (2) loss of interest or pleasure. There must be some form of impairment and the condition is not able to be explained better by something else.

The good news is that awareness is growing and there are highly effective treatments available – including biological, psychological, and lifestyle modifications.

How Does Major Depression Come About?

MDD may arise gradually; it may initially present with changes in sleep or energy, rather than subjective complaints of depressed mood. It’s important to keep this in mind when you’re assessing a patient with a possible mood disorder. Sometimes people may find it difficult to describe their mood state.  

The course of illness varies. Some patients with MDD will achieve full remission in symptoms, but in other patients, symptoms can persist for months to years. Depression is generally a recurrent condition. Most mood disorders need to be managed as long -term conditions. Some patients remain depressed, with fluctuations in symptom severity.

It’s important to consider the impact of the illness upon the patient, their relationships, career, and physical health. It’s also critical to consider suicide risk in the depressed patient.

The Impact of Depression on Others.

MDD doesn’t just affect the patient – it impacts upon carers, partners, family members, and friends too! So its important to include these people in the assessment, diagnosis, education and management plan.

Rates of depression in carers is reported to be far higher than the normal population.

Differential Diagnosis.

It’s always important to consider differential diagnoses including grief and other psychiatric disorders. (e.g. Substance use, personality disorders, anxiety disorders) in any patient presenting with depressive symptoms. Depression can also arise in context of physical illness. It’s not hard to imagine why dealing with a long term illness or chronic pain may be associated with depression.

Be aware that MDD has both cognitive AND biological symptoms. Cognitive symptoms relate to negative and self-defeating patterns of thought about self, the world, and the future (sometimes referred to as “Beck’s cognitive triad“).

When someone is presenting with MDD, it’s always helpful to consider triggers or precipitants which have led to the illness. These may include stressful life events such as the breakdown of a relationship, the death of a loved one, or the loss of a job. Stressful life events are different for each person – and it’s important to consider the unique circumstances of the patient in front of you.

Some personality styles are more predisposed to developing a depressive disorder, for example people who are prone to worry, self-doubt, low self-esteem, or more sensitive to rejection or criticism.

Note: symptoms od depression can cause clinically significant distress or impairment in social, occupational, or other areas of functioning. Other exclusion criteria include:  the episode is not attributable to the physiological effects of a substance or medical condition, not better explained by another psychiatric disorder, there has never been a manic or hypomanic episode.

Other Forms of Depression

Apart from major depressive disorder, the DSM lists persistent depressive disorder and disruptive mood dysregulation disorder as other primary depressive disorders. Persistent depressive disorder is like a chronic low grade depression (previously referred to as ‘dysthymia’), often lasting several years. These patients will often complain of being depressed for several years, sometimes their whole lives.

Other depressive disorders include premenstrual dysphoric disorder, substance/medication-induced mood disorder, or mood disorder secondary to a medical condition. It’s worth being aware of these – particularly if the depressive symptoms begin following ovulation and improve with the onset of menses (as in premenstrual dysphoric disorder), or depressive symptoms occur in the context of substance use/ medications or medical illness.

Don’t Forget Bipolar Depression.

Finally, don’t forget that patients with Bipolar Disorder can and do experience depression. In fact, it is often the case that individuals experience one or more episodes of depression before presenting with a hypomanic or manic episode. At which point Bipolar Disorder is diagnosed.

It is important to check for a family history of Bipolar Depression in any patient with depression and warn all patients who are being treated with medication for depression of the risk of mania.

Types of Depression.

There are a few particular subtypes of depression which medical students should be aware of:

Melancholic depression is a subtype of depression. It’s characterised by anhedonia, and or lack of reactivity to usually pleasureable stimuli + 3 of the following: Distinct quality to depressed mood, worse in the morning( diurnal variation), early morning awakening, marked psychomotor disturbance( agitation or retardation), significant  weight loss or loss of appetite, excessive or inappropriate guilt.

Depression with psychotic features is another subtype of severe depression, where the patient loses touch with reality. They present with depressive AND psychotic symptoms – delusions, hallucinations and thought disorder.

When patients are depressed and experiencing psychotic symptoms these are often (but not always) mood-congruent delusions/hallucinations: Mood-congruent means the delusions or hallucinations are consistent with how the person is feeling at the time. Which in the case of depression means that the patient will have depressive themes, e.g. personal inadequacy, guilt, disease, deserved punishment, death, nihilism. Mood-incongruent delusions/hallucinations in depression are not typical for depressive themes (for example these may be paranoid or bizarre or even grandiose in nature).

It’s important to be aware that melancholic depression responds better to biological treatments for depression such as antidepressants or ECT. Psychotic depression also requires biological treatments, usually a combination of antidepressants, antipsychotics, or ECT.

How We Treat Depression.

Treatment goals for MDD include optimising mood, treating any comorbidities, facilitating a return to premorbid functioning, and relapse prevention.

Lifestyle Is Important.

It’s also important to encourage patients to incorporate healthy lifestyle modifications – such as exercise, healthy diet, and smoking cessation, reducing alcohol /other substances, sleep hygiene, incorporating relaxation techniques, and increasing social engagement.

As clinicians when we are giving parents advice about depression we should always consider pharmacological, psychological, and lifestyle modifications. So what factors help guide treatment choice?

The Role Of Antidepressants.

It’s important to be aware that antidepressants are generally indicated in moderate to severe depression. Regarding choice of antidepressants, it’s common to see SSRIs and SNRIs used first line, then tricyclics and MAOIs as second line options.

Psychological Interventions.

There is a range of psychological therapies that can help with depression. Evidence supports the use of psychological therapies such as psychoeducation, Cognitive Behavioural Therapy (CBT), interpersonal therapy (IPT), Acceptance and Commitment therapy (ACT), and Mindfulness based cognitive therapy. It’s worth being familiar with the way at least one type of therapy works.

Online Therapies.

There are a wide array of online web therapy applications available to people with depression. Many with a strong evidence base. Online therapy can be hard to define. It can just be a series of educational but helpful blog posts or videos. Or it can be an actual elearning course where you teach your self something like CBT or mindfulness. Or it can be a therapist working with you online using some sort of video technology. Or it can be a combination of the above.

Some of the more popular and credible sites are MoodGym and ThisWayUp

Psychoeducation.

As we have noted above the role of psychoeducation is important in helping any patient with depression. As a clinician you should take the time to explain things properly and give resources. Remember cognitive slowness and thought problems are an issue for many people with depression. Don’t forget to provide information to carers and family members.

Combining Treatments.

Patients often think that it is either antidepressants or psychotherapy. But actually that is not the case. Most patients benefit more from a combination of antidepressants and psychological approaches.

Related Questions.

Question: How long would you treat someone with antidepressant medication?

Answer. General wisdom suggests maintenance antidepressants for at least six months post recovery.  However, some patients with recurrent depressive episodes will require lifelong treatment.

Question: Are there medical conditions that are associated with depression?  

Answer. Absolutely. A number of medical conditions are known to either be associated with or a direct medical cause for depression. These can include conditions that directly affect the brain, such as stroke or parkinson’s syndrome, as well as a whole host of chronic medical conditions, such as hepatitis, HIV/AIDS and arthritis.

Question: How do you differentiate depression from grief? What are some helpful differences to consider?

In previous versions of DSM the term grief was used as an exclusion criteria for being depressed. This is no more. It was being found that there were cases of depression which were being overlooked because it was assumed that the person was simply sad because of their loss. Yet the sadness was continuing on far longer and at a greater extreme than should normally occur. Whilst grief and loss are common experiences with known psychological impacts if someone who has recently been bereaved is experiencing symptoms of depression we now call this depression. So the simple answer to this question is that grief can now be seen as a possible precipitant for why someone would become depressed.

Question: What are some important psychiatric comorbidities to consider in the depressed patient?

Answer. As is the case in most of mental health it is far more likely that a patient with one mental health diagnosis has a second or third one than just one. This is partly due to the somewhat arbitrary nature of our current classification symptoms. Regardless there are a number of common conditions associated with Major Depression.

Firstly, you should be aware that up to 80% of patients with Depression have a significant anxiety component and for many such patients they will probably also have a formal anxiety disorder. So expect to see things like Generalized Anxiety Disorder and Panic Disorder as well as PTSD.

Secondly, don’t ignore the role that substances, in particular, alcohol, play in depression.

Question: What are the risk factors for the development of major depressive disorder?

Answer. There are many known risk factors for depression, including genetics and family history, prior history of depression, recent loss or trauma, medical illnesses and substance abuse. Depression is also more commonly diagnosed in women than in men as well as younger and older people.

Further reading/suggested resources:

Castle D et al, A primer of Clinical Psychiatry, Elsevier, 2^nd edition, 2013

Bloch, S et al, Foundations of Clinical psychiatry, Melbourne University Press, 4^th edition

Diagnostic and statistical manual of mental disorders (DSM V), fifth edition, American Psychiatric association, 2013