Formulating and empirically testing hypotheses lies at the core of the scientific method, and is a cornerstone for practicing evidence-based medicine – especially if and when the evidence base for a given problem may not yet be so well developed in the literature. Whether we realize it or not, every clinical encounter is essentially the buildup to generating a hypothesis – a framework for explaining how and why a set of problems arose, and then figuring out whether the available information supports or refutes the proposed explanation. A hypothesis is a testable, falsifiable question posed about the association between two variables.

Clarity about the intended targets of treatment is, by necessity, a prerequisite for any psychiatric or other medical intervention. One cannot make sensible treatment decisions unless one knows with some degree of confidence what exactly constitutes the object of treatment. Yet, by and large, psychiatric diagnoses are made on purely clinical grounds – meaning, they derive from collections of signs and symptoms that cohere in an organized fashion, seldom with definitive corroboration by an external biomarker. (Some exceptions to this might include positive blood or urine toxicology screens to affirm the diagnosis of alcohol or other substance intoxications; low cerebrospinal fluid levels of orexin to diagnose narcolepsy; or neuroimaging or other laboratory tests that affirm an underlying nonpsychiatric medical condition (such as a brain malignancy, or metabolic derangement) that might explain an acute mental status change.) Herein lies a dilemma: while evidence-based treatment means identifying a plausible working diagnosis, categorical diagnoses cannot always be made with the degree of exactitude one might otherwise hope for.

If we had to pick the single most important factor that goes into clinical decision-making in psychiatry, it would not be anything related to pharmacology, psychotherapy, genetics, Maudsley staging scores, or any other kinds of historical illness characteristics, but rather, it would be determining the appropriate level of care needed for a given individual patient. Why is that, given the many breakthroughs in neuroscience and our understanding of psychopharmacology? Nobel prizes have been awarded for elucidating the intricacies of second messenger signal transduction in neurons, but not for the intricacies of deducing the merits of an intensive outpatient program versus a partial hospital program. Or for knowing when a multidisciplinary “team” approach is wiser than being seen by an individual practitioner. For all the attention heaped upon presumptive brain mechanisms of psychopathology and the impact of evidence-based treatments thought to modulate brain dysfunction, one cannot escape the psychosocial context in which most mental health conditions arise. Chronic and recurrent mental health conditions often spill into people’s daily lives in ways that can be tumultuous, volatile, and precarious. Coping with distress and adversity often can become a primary goal of treatment, and for some difficult-to-treat psychiatric conditions, questing for a medicine to eradicate chronic symptoms may sometimes need relegation to a secondary rather than primary objective. Many treatments in psychiatry are more disease-managing than disease-modifying (meaning, they may lessen the adverse impact of psychiatric symptoms but not necessarily eradicate or prevent them).

Thus far we have discussed how clinicians are the primary if not sole evaluators and decision-makers when it comes to devising treatment recommendations. Shared decision-making (SDM) is a not-so-new but increasingly recognized form of patient-centered care in which a patient and their clinician actively collaborate to determine which treatment options are most consistent with the patient’s own values, priorities and goals. As described originally by Charles et al. (1997) and later expanded on by Elwyn et al. (2012), an SDM model first involves introducing choice followed by describing options (sometimes using patient decision-support tools – such as charts, graphs, brochures, interactive websites, or audiovisual materials) followed by helping patients explore their preferences in order to make the best decisions for them. Greater focus is placed on the patient’s own narrative and personal experience as influencing treatment decisions, rather than on general diagnostic issues or outcomes.

The core foundation of excellent psychiatric treatment starts with obtaining a coherent history, preferably as a longitudinal narrative that follows a chronological timeline, with an emphasis on parsing relevant pertinent “positives” and “negatives” from that narrative. A simple organizing principle is to have patients present their concerns from a chronological perspective, in order for the clinician to develop a clear narrative. “When was the very first time you recall having any problems involving your mental health?” provides a good starting point, followed by “When was the first time you sought any kind of treatment for those problems?” A chronologically organized narrative gives some sense not only about the backdrop and longevity of a psychiatric disorder but, moreover, clues about the degree of distress and disruption caused by symptoms, the potential duration of untreated illness, and symptom severity as reflected by the kinds of interventions that previously occurred. A clinical timeline that starts with years of psychotherapy differs from one that begins with an involuntary psychiatric hospitalization or a suicide attempt; low-grade symptoms that persist for extended periods unnoticed by others, or cause no outward functional impairment, imply a different level of severity and debilitation, and possible prognosis, from those linked with more obvious outward signs of disability. For persistent problems, one always wonders why the patient is seeking help now and not a week or month or two ago.

Deciding when psychiatric medications or other types of treatments are indicated – and defining precise targets and goals of treatment – is perhaps the most fundamental of all undertakings in clinical psychiatry. As with all medical treatments, clinicians and patients should both have a clear and explicit understanding of what they expect medications, psychotherapy, or other interventions, to do. Medicines do not fix bad relationships or resolve existential dilemmas, but they can equip people with more intact capabilities to solve problems through better concentration and executive functioning, or improve someone’s capacity to negotiate stresses with less bias and influence from distorted beliefs or intense emotions. Pharmacotherapy is somewhat analogous to eyeglasses when it comes to driving a car; glasses do not confer driving skills but they can help minimize visual obstructions and improve how the brain processes information in ways that might otherwise prevent someone from making the fullest use of their knowledge about the rules of the road. Psychotherapy constitutes driving lessons.

In preceding chapters, we have focused mainly on how to think through clinical problems that are often ambiguous or have multiple viable solutions, each with their respective pros and cons. We have deliberately refrained from offering specific recommendations about “what to do” in a given situation when no single best answer may exist. When that happens, the clinician’s task involves framing testable hypotheses and applying a reasoning process to arrive at a sensible individualized treatment regimen (ITR) for a given patient based on their unique clinical profile. Our goal has been to steer readers away from one-size-fit-all protocol-driven care and replace that approach with a more decision-analytic patient-specific iterative strategy, where nodes along a decision tree are determined by the personalized characteristics of a given individual.

Part of the intellectual intrigue for many people who choose a career in mental health is the challenge of reading between the clinical lines and sussing out information that transcends the obvious. Do patients’ words and behaviors align? Are subjective symptoms consistent with overt functioning? Does a clinical narrative conform to a set of circumstances? How does a clinician know when someone is lying, concealing key information, embellishing facts, or otherwise operating with an agenda? Or what if the patient has no vocabulary for accurately communicating their internal experience, and it is left to the clinician to deduce what may actually be happening for them internally? A clinician’s ability to recognize the unspoken parameters of psychiatric communication pertains to many if not most forms of mental illness, either by intention or happenstance, since patients themselves may not always be fully aware of what it is that they want or need. Clinical decision-making can only be as sound and logical as the quality of information made available to the decision-maker. Herein lies the challenge both for assessment and treatment planning when the patient is less than forthcoming, deceptive, confabulating, confused, denying, demented, delirious, malingering, ashamed, scared, alexithymic, misinformed, or otherwise less than a full-fledged participant in their own care.

“Measurement-based care” (MBC) refers to the systematic assessment of patients’ symptoms over the course of some observation period in order to glean information about likely treatment effects. The concept grew mainly from the world of clinical trials and US Food and Drug Administration registration studies, where efforts to judge the efficacy of an intervention depended on reliable quantifiable measures to track changes in symptoms or clinical status over time. In this chapter, our interest in MBC pertains mainly to describing the ways in which it can impact hypothesis-testing, decision-making, and outcome-tracking in clinical practice rather than in research settings.

More often than not, an initial intervention in psychiatry requires modification. Sometimes sooner than later, the clinician must judge whether a medication dose needs adjustment, an augmentation is warranted, or an outright change should occur when something has been tried and deemed to be unsuccessful. Perhaps a new additional diagnosis comes to light (such as alcohol or substance use disorder) requiring its own treatment. Or an insurmountable medication intolerance develops. Or the originally identified target symptoms worsen, metamorphose, or persist long enough after a previous medication change to warrant a further alteration. Other times, changes to a regimen happen not necessarily because sufficient time has elapsed to deem a change necessary, but because a patient’s (or significant other’s) capacity to tolerate negative affect or other elements of distress become saturated, prompting entreaties or outright demands to “do” something that seems more proactive. In all such instances, there is seldom if ever only one correct approach to iterative pharmacotherapy.